Roe I Biplane

  A. V. Roe’s first man-carrying aircraft was a canard biplane of wire braced, wooden construction, similar to the Wright-type model with which he won £75 at Alexandra Palace in April 1907. The aircraft was built round a large white wood, three bay, triangular structure mounted on four homemade pneumatic tyred wheels, the front pair being steerable. The pilot sat in the forward part of the machine and a 6 hp J.A.P. air-cooled motorcycle engine was situated amidships, driving a 6 ft 2 in diameter two bladed paddle-like pusher airscrew of 3 ft pitch through five feet of extension shafting which formed the apex of the central structure. Wing construction was primitive, the kauri main spars being external and therefore thin to reduce drag. For rigidity it was necessary to employ a large number of bracing wires and kingposts with the result that the cotton covering could only be applied to the underside of each wing, the erroneous belief being that lift was only generated by pressure on the undersurfaces. The covering was then tightened with a coat of size and the whole wing structure braced from three much taller kingposts. There were no ailerons and no rudder but a car-type steering column warped and pivoted the large front elevator and so gave both lateral and fore-and-aft control. A. V. Roe was the true inventor of the single-lever type of control and had patented such a system as early as 1906, ante-dating the claims of Continental inventors by several years.
  The Roe I biplane was built in the stables behind the surgery of A. V. Roe’s brother Dr. S. Verdon Roe at 47 West Hill, Putney, London, and on completion in September 1907 was taken to Brooklands, where Roe hoped to make an attempt to win at least two of the prizes on offer for successful powered flight. The Brooklands Automobile Racing Club had offered £2,500 for the first flight round their three-mile circuit before the end of that year, stipulating that it should be completed at not less than 10 mph and at a height of between 30 and 50 ft, and The Graphic and Daily Graphic were offering £1,000 ‘to the inventor who first produces a machine which, being heavier than air, shall fly, with one or more human passengers, between two given points not less than one mile apart.’
  Although a great deal of taxying was done along the concrete track, the 6 hp engine was not powerful enough and the biplane flew only when towed by friendly racing motorists. Such flights were successful on straight tows, but turns resulted in sideslips and damage until Roe designed a quick-release which enabled him to cast off at will and make controlled landings. In this way he learned the feel of the controls but the end of the year came without the prize being awarded.
  ‘A. V.’ then negotiated the loan of a 24 hp Antoinette eight cylinder, water-cooled engine designed and built in France by Levasseur. It had copper water jackets and direct petrol injection and on its arrival in May 1908, gave Roe the extra power he so badly needed. To carry the increased weight, extra wing area was provided by inserting short stub wings at mid gap in the inner wing bays. Unfortunately the extra power was more than his airscrews could absorb and many blade failures occurred, but the trouble was eventually cured and in the early morning of June 8, 1908, he succeeded in taking the biplane off under its own power and in making several hops at a height of 2 to 3 ft. above the track. A. V. Roe did not publicise his achievement and two years passed before he let it be known that he had left the ground in 1908. In 1928-29 the Gorrell Committee of the Royal Aero Club disallowed his claim to have been the first to fly in Britain on the grounds that he had not been airborne for a sufficient distance, ruling that the first Briton to do so had been J. T. C. Moore-Brabazon in a Voisin biplane at Eastchurch nearly a year later.
  During his long stay at Brooklands, Roe received no encouragement from his landlords. Indeed, the Clerk of the Course, E. Rodakowsky was at times openly hostile to aeroplanes, and at the start of the 1908 motor racing season insisted that Roe’s shed be painted dark green and be moved from its original site alongside the finishing straight, close to the judge’s box, to the other side of the paddock. The shed was also pressed into service as a refreshment room on race days and it was on the first such occasion that Rodakowsky ordered Roe’s biplane to be lifted over 5 ft railings into an adjoining field. During this exercise, track attendants stumbled under the load in the gusty conditions and dropped the machine into a dried-up dyke breaking some ribs. Some further damage was caused by mishandling but the machine was repaired and six trials were possible before Roe was evicted from Brooklands on July 17, having been given two weeks’ notice on July 4. The Antoinette engine was then returned to France as Roe could not afford to buy it and the biplane dismantled. A wheel and a few other selected parts were kept by Roe to remind him of some of the ingenious constructional methods he had used. In later years these items were preserved in a glass case at his home as part of the Roe private aeronautical collection.


SPECIFICATION AND DATA
   Construction: By A. V. Roe at 47 West Hill, Putney, London, S.W.15
   Power Plants:
   One 6 h.p. J.A.P.
   One 24 h.p. Antoinette
   Dimensions:
   Span 36 ft (upper wing) 30 ft (lower wing)
   Length 23 ft.
   Weights:
   Tare weight 350 lb. All-up weight 650 lb.
   Weight of Antoinette engine (without radiator) 98 lb.

Roe I Triplane

  After his eviction from Brooklands, A. V. Roe turned his attention to a triplane design. In January 1909 he filed a patent for a novel control system applied to a tandem triplane arrangement. The main wings provided control in the pitching plane by varying incidence, operated by fore and aft movements of the pilot’s control lever. Side to side movement of the same lever warped the centre wing, and the upper and lower wings were warped in unison by the rear wing struts acting as push rods. The rear triplane unit acted simply as a fixed lifting surface; a rudder behind this was operated in consort with the wing warping.
  Early in 1909, Roe began work on two triplanes for which engine manufacturer J. A. Prestwich agreed to supply two of his J.A.P. engines. The larger machine, intended to have a 35 hp engine, was apparently built with financial support from motor dealer George Friswell, but before it was completed the partnership was dissolved. The incomplete airframe was subsequently auctioned at Friswell’s Sales Rooms in Albany Street, London, where it realised £5 10s (£4 19s after commission).
  For his own use, Roe designed a machine to use a four-cylinder inline engine of 10 hp. Unfortunately this engine failed on test in the J.A.P. factory, so Prestwich agreed to build a two-cylinder engine of similar power. Until this was ready, Roe had to install the 6 hp engine from his Brooklands biplane.
  The new triplane closely resembled the patent drawings. The two sets of wings were joined by a fuselage of triangular section, with three deal longerons joined by cross struts and wire braced. The main undercarriage consisted of two cycle wheels in reversed forks, with a smaller cycle wheel under the rear fuselage ahead of the tail unit. The wings were each made in three panels, with internal wooden structure of spars and ribs. For lightness and cheapness, the surfaces were covered with wrapping paper with open weave fabric backing. A coat of yellowish varnish earned the machine the ironic name of Yellow Peril later in its career.
  The components of both triplanes were made at Putney early in 1909 while Roe sought a flying ground. After a protracted search, he found the open space of Walthamstow Marshes alongside the River Lea in Essex, where he was able to rent an arch under the Great Eastern Railway’s bridge across the river. Erection of the two triplanes under the archway probably began in March, and after the larger unfinished machine had been removed, taxying trials with the 6 hp engine began in April. By this time, Roe’s younger brother Humphrey had agreed to provide financial support. He owned a factory in Manchester whose best-known product was gentlemen’s trouser braces sold under the trade-mark ‘Bulls Eye’; in recognition of this sponsorship, A. V. Roe added the name ‘Bulls Eye’ to the side of the triplane, which already carried his own trade name ‘Avroplane’.
  The new J.A.P. engine arrived about the end of May. It was a V-Twin with the same 50 degree angle as the 6 hp engine but had mechanically operated overhead valves and, from mid-June, a Simms magneto replacing the battery and coil ignition. Although it only provided 9 hp instead of the promised 10 hp, this was sufficient to enable Roe to get airborne for brief hops from June 5, making (in his own words) ‘dozens of short flights up to 50 ft in length at a height of 2-3 ft, which were hardly more than jumps.’
  The propeller was mounted on a drive-shaft above the engine, with belt-drive from a pulley on the engine to a larger pulley on the propeller shaft. Varying pulley size allowed different gear ratios, and the pitch of the propeller blades could be adjusted on the ground between flights. After a series of trials in which Roe investigated the effect of these variations, and also refined his piloting technique, on Friday July 23 he made three flights of about 900 ft at an average height of 10 ft, thus becoming the first to fly an all British aeroplane with a British engine over British soil.
  Further flights were made during the next two months, interspersed with mishaps leading to repairs and modifications. Skids were fitted under the wing tips, and later removed; the pilot’s seat was moved forward, and then the engine was moved forward, so that the drive wheel on the propeller shaft was ahead of the centre wing spar. Finally, the belt-drive was replaced by a motor cycle chain between pinions on the engine and propeller shafts.
  In this form, and with the vertical fin surfaces in the tail unit removed, the first triplane appeared at the Blackpool meeting of October 18-24. It made a few short hops of up to 150 ft on October 19 but according to contemporary reports it was suffering from engine trouble; Roe himself later suggested that the main trouble was heavy rain soaking the paper covering.
  Roe took two machines to Blackpool; the second aircraft was similar to the original, but was designed to have a new four-cylinder engine which was intended to produce 20 hp but which seems to have only produced about 14 hp. This new engine arrived in Blackpool at mid-week and Roe had the second aircraft ready to fly by October 21, but storms prevented any further flying.
  Blackpool Week 1909 ended the active career of the first Roe I triplane. It made a brief reappearance at an aero exhibition held at Belle Vue Gardens, Manchester, January 1-3, 1914, spent 11 years in storage at the Manchester factory, and was presented in 1925 to the Science Museum at South Kensington, London where it remains on permanent exhibition.
  The airframe of the second Roe I triplane closely resembled that of the first but fortunately there were several prominent recognition features which made it easily distinguishable from its forebear. Whereas the earlier aircraft had a fuselage of constant depth and large tail wheel, the second fuselage was tapered towards the rear and equipped with a long tail skid. There were also additional struts in the undercarriage. The first machine had a small fuel tank mounted on a fuselage longeron but the second had a narrow, cigar-shaped tank on struts ahead of the pilot to give a greater head of fuel. It must also be remembered that only the first triplane bore the fuselage inscription ‘Bulls Eye Avroplane’ under which appeared a clearly painted figure 3, indicating that the inventor regarded it as his third individual aeroplane. He had meanwhile been evicted from Lea Marshes and on his return from Blackpool, transferred to Old Deer Park, Richmond, Surrey. The new site proved unsuitable and late in November 1909 he moved to Wembley Park, Middlesex, where on December 6 the second Roe I triplane made its first exploratory flights with encouragingly few mishaps. The bigger engine improved the performance to the point where local authorities sportingly felled a number of trees to enable him to fly a circular course and land back at his starting point. Attempts to improve the control system were not always successful as on Christmas Eve 1909 when Roe found it impossible to lift the port wings quickly enough and sideslipped into the ground, once more demolishing the port mainplanes.
  In January 1910, with financial help from his brother H. V. Roe, the private firm of A. V. Roe and Company was formed with workshop space in the factory of Everard and Company at Brownsfield Mills, Manchester. Wembley Park flying ground was retained until Maj Lindsay Lloyd converted the centre of Brooklands track into an aerodrome. ‘A.V.’ then returned to the scene of his 1908 experiments and made three half-mile introductory flights there on March 11, 1910. He then left for London to look after his new Roe II triplane, the first example of which, named Mercury, was that day introduced to the public at the Olympia Aero Show. No doubt influenced by the success of contemporary biplanes, he later tried out this configuration using the second Roe I triplane as a guinea pig. All three outer wing panels were removed and the top two replaced by others similar to, but longer than, those of the Roe II Mercury. At the same time a Mercury-type bottom centre section and improved undercarriage were fitted. The tail wheel from the original Roe I triplane was borrowed and fitted into a strengthened mounting, a piece of cannibalism which explains its absence from the Science Museum exhibit to this day. When flown in this guise at Brooklands on Easter Monday 1910, the aircraft was nicknamed the ‘Two-and-a-Bit Plane’ but the advent of newer designs speedily ended its career and the old aircraft was dismantled at Brooklands at the end of the following month.


SPECIFICATION AND DATA
   Construction: By A. V. Roe at 47 West Hill, Putney, London, S.W.15; erected at Lea Marshes, Essex (1st machine) and Blackpool, Lanes. (2nd machine)
   Power Plants:
   One 10 h.p. J.A.P.
   One 20 h.p. J.A.P.
   Dimensions:
   Span 20 ft. 0 in. Length 23 ft. 0 in.
   Wing Area 285 sq. ft.
   Tailplane span 10 ft. 0 in.
   Tailplane area 35 sq. ft.
   Weights: Tare weight 300 lb. All-up weight 450 lb.
   Performance: Speed 25 m.p.h. Range 500 yards
   Production:
   No. 1 Fitted with 2 cylinder 10 h.p. J.A.P., small fuel tank and tail wheel; preserved without engine or tail wheel at the Science Museum, South Kensington, London
   No. 2 Fitted with 4 cylinder 20 h.p. J.A.P., raised cylindrical fuel tank and tail skid; wings and undercarriage modified 4.10; dismantled at Brooklands 5.10


Roe II Triplane

  First product of the newly formed A. V. Roe and Company was a single seat triplane known as the Roe II. This was approximately equal in size to the original machine but was fitted with a 35 hp Green four-cylinder, water-cooled engine driving a birch two-bladed, adjustable-pitch airscrew. Cooling was by means of two spiral tube radiators built into, and fitting flush with, the sides of the front fuselage. The new triplane was structurally superior to its predecessors, with silver spruce struts and spars, and an ash fuselage covered with Pegamoid fabric. The undercarriage was a rigid triangulated structure to which the two-wheeled axle was secured by rubber shock absorber cord. Climbing and diving control was improved by pivoting the entire triplane tail and linking it to the mainplane variable incidence gear, the range of movement being from four to eleven degrees of incidence.
  Named Mercury with due ceremony by the Lord Mayor’s daughter, the first Roe II triplane occupied the place of honour at the Manchester Aero Club’s model aircraft exhibition at White City, Manchester, on March 4, 1910, and although it had not yet flown, was priced at £550 (with tuition). A week later it was again exhibited at the London Olympia Aero Show of March 11-19, where the Prince and Princess of Wales were shown round the machine by A. V. Roe and an order was received from W. G. Windham, later Sir Walter Windham MP, a manufacturer of motor car bodies at Clapham Junction. References to the sale of yet another Roe II triplane to the Rangie Cycle Company appeared in several publications at the time but there is no evidence that such an aircraft was ever built.
  The exhibition machine Mercury was retained by A. V. Roe for school and experimental use but when flight trials began at Brooklands, it rolled on take-off and twice landed upside down. The second crash (by pupil Job), April 17, 1910, resulted in the destruction of the undercarriage and most of the mainplanes. During reconstruction Roe took the opportunity of correcting the C. G. position by moving forward the pilot’s seat, and abandoned wing warping. The control column was remounted on a universal joint, large unbalanced ailerons were hinged to the trailing edge of the top wing, and a tall rectangular rudder more than twice the area of the original was fitted. Ten days were sufficient to complete this work and Mercury was out again for taxying trials on April 27.
  W. G. Windham’s aircraft was delivered to Brooklands early in May and assembled during Whitsun. First hops were made on May 26 by A. V. Roe who then handed it over to the owner for some preliminary taxying. The amount of flying done on this machine is uncertain but it is known that Windham landed in soft ground at Brooklands on July 12 and turned the triplane over on its back.
  Accidents to Mercury were now much less frequent and on Thursday June 2, Roe made several circuits of Brooklands at a height of 20 ft and executed a number of fairly steep turns. At the end of July it was dismantled and taken to Weybridge station along with its successor, Roe III, for despatch by rail to the Blackpool Flying Meeting of August 1, 1910. Hopes of winning the prize money so necessary for future experiments were dashed when sparks from the engine of the LNWR goods train set fire to their truck while puffing up an incline near Wigan on July 27. Both aircraft were reduced to ashes.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company, Brownsfield Mills, Great Ancoats Street, Manchester; and Brooklands Aerodrome, Byfleet, Surrey.
   Power Plant: One 35 h.p. Green
   Dimensions:
   Span 26 ft. 0 in. Length 23 ft. 0 in. Height 9 ft. 0 in.
   Wing area 280 sq. ft.
   Weights:
   Weight of engine without flywheel 150 lb.
   All-up weight 550 lb.
   Performance: Maximum speed 40 m.p.h.
   Production:
   No. 1 "Mercury", Avro experimental, burned out near Wigan 27.7.10
   No. 2 For W. G. Windham, Brooklands

Roe III Triplane

  The ‘prototype’ Roe III was a two-seater, structurally similar to Roe II, but with the important difference that the mainplanes were fixed to the fuselage, climbing and diving being effected for the first time by means of a tail elevator. The aspect ratio was 8 and the bottom wing was cut back to a span of only 20 feet. The lifting tail remained, but as a result of experiments with the triplane Mercury, lateral control was by means of ailerons (5 ft span by 2 ft chord), this time hinged to the rear spar of the top wing so that they were slightly inset. By this time the functions of the rudder were better understood and this organ was increased in size to a rectangle equal in height to the maximum tailplane gap as on the modified Roe II. A more robust undercarriage was of the twin-skid, four wheel Farman type and the engine a 35 hp J.A.P. eight-cylinder vee air-cooled unit.
  First taxying trials were made at Brooklands by A. V. Roe on the evening of June 21, 1910, and the first straights were flown in a tricky wind on June 24. Flight times gradually increased until on July 4 he made a best flight of 11 minutes (with ‘just a touch’ after 3) minutes) and later in the day carried his mother and several other passengers. Roe seldom exceeded 20 minutes in the air in the ‘prototype’ Roe III because the J.A.P. engine had a tendency to overheat and cover pilot and passenger with sooty oil ejected from the scavenging holes at the base of the cylinder walls. Carburettor fires were frequent but Roe persevered until on July 9 he remained aloft for 25 minutes and made comparatively steep turns. He also practised figure eights in readiness for Royal Aero Club tests which he passed on this aircraft on July 20. Aviator’s Certificate No. 18 was issued to the great pioneer on July 26, but within a year he had given up piloting in favour of designing and did not take the Air Ministry’s ‘A’ Licence tests when they came into being in 1919. He kept no log books and did not know how many hours he had flown as a pilot. The J.A.P. engined Roe III was advertised secondhand by the makers for £250 in May 1911 but its ultimate fate is uncertain.
  The three subsequent triplanes of this type (all powered by 35 hp Green four cylinder, water-cooled engines) had the span of the top mainplane increased to 31 ft and were fitted with ailerons hinged to the rear spar of the centre wing. First of these, identified by rounded comers to the trailing edge of the rudder and by fuselage covering applied only in the region of the cockpits, was a special slow flying aircraft with a more heavily cambered wing section for instructional use at the Avro School. Piloted by the designer, this triplane first flew at Brooklands on July 9, 1910, and its performance was at once encouraging. Both Roe and Pixton carried passengers on July 13 and one another on the following day. At the end of the month the machine was sent by train from Weybridge to the Blackpool meeting only to be destroyed by fire en route, as was the Roe II Mercury.
  Determined to compete, Roe and Pixton hastily brought spare components from the Manchester works to Blackpool and arranged for a new engine to be delivered direct from the Green factory. Work started on Thursday July 28 and the finished aircraft flew on Monday August 1, much of the erection having been done by Roe himself during the previous night. There was not even time to cover the fuselage. Three attempts were made to take off, during which a tyre burst and some rubber shock absorbers snapped. Two struts were broken on landing but not before Roe had made four circuits of the course, at least two with passengers (who could face forward or backward according to taste). For this he received a special merit award of £50. August 2 dawned wet and windy but after repairs Roe succeeded in making two more short hops at 7.30 p.m. and on the following afternoon left the ground in a much more lively manner. In turning, the wind carried him dangerously close to one of the pylons, to avoid which he had no alternative but to make a crash landing, breaking several more struts, the airscrew and one mainplane.
  Visitors to the Blackpool meeting included J. V. Martin, Organiser of the Harvard University Aeronautical Society, who ordered a Roe III triplane which was built, crated and despatched (without engine) to the USA by August 13! A. V. Roe and Claude Grahame-White were also invited to fly at the Boston Aviation Meeting scheduled to open on September 2. They left in the White Star liner Cymric on August 23, Roe taking with him the makeshift Blackpool triplane in a 40 ft packing case. Arriving at Boston on September 1, they collected the Harvard Society’s triplane (which had been stored at East Boston Docks since its arrival in the Cunarder Ivernia a week previously), and took all the aircraft by lighter to the airfield at Squantum Point. Here Roe and mechanics Pixton and Halstead complete the erection of the Blackpool triplane on September 3, but flights begun on September 6 were disappointing, the longest being 75 ft at a height of 10 ft. At 5 p.m. the engine failed and the triplane landed heavily in front of the grandstand, damaging the starboard mainplanes and undercarriage. Local woodworker C. H. Metz made a new airscrew and at 6.30 p.m. on September 8 Roe succeeded in leaving the ground properly for the first time, reaching a height of 30 feet. When he shut off the engine to land, however, a sudden gust caused the aircraft to swerve to starboard and dig the right undercarriage skid into the ground, causing it to swing round with major breakages. Roe was unhurt and more determined than ever to show the Americans that his triplanes were more than just interesting freaks. On September 9 he secured permission from Harvard to erect the Society’s triplane and fit it with the 35 hp Green engine taken from the wreck. Erection was completed and engine runs made on September 12 and it is said that the aircraft was slightly heavier than its predecessor and had two instead of four wheels. Two days later, amid the applause of 10,000 spectators, successful flights were made up to a height of 50 feet but the engine still refused to give full power. After tinkering with it for most of September 15, Roe made a good take-off at 4.20 p.m. and flew the length of the field. In attempting to round the pylon, he sideslipped into the ground from 50 feet, totally wrecking the port side of the aircraft and suffering a severe scalp wound. A cordon of police saved the wreck from souvenir hunters and after A. V. Roe returned to England, Pixton built a new triplane for Harvard out of the remains of the other two. He then sold the surplus spares to the local aircraft firm of Burgess and Co and Curtiss of Marblehead to raise money for his passage home, leaving Harvard with their machine untested in the air.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company, Brownsfield Mills, Great Ancoats Street, Manchester; and Brooklands Aerodrome, Byfleet, Surrey
   Power Plants:
   One 35 h.p. J.A.P.
   One 35 h.p. Green
   Dimensions:
   Span (upper) 31 ft. 0 in. (lower) 20 ft. 0 in.
   Length 23 ft. 0 in. Wing area 287 sq. ft.
   Tailplane area 75 sq. ft.
   Weight: All-up weight 750 lb.
   Production:
   No. 1 Prototype with 35 h.p. J.A.P., first flown 24.6.10, up for sale 5.11
   No. 2 Avro School machine, first flown 9.7.10, burned out 27.7.10
   No. 3 Blackpool makeshift machine, first flown 1.8.10, crashed at Boston, U.S.A. 8.9.10
   No. 4 Harvard Aeronautical Society machine, first flown (and crashed) at Boston, U.S.A. 15.9.10

   Note: A work of reference of the period states that a triplane of this type was built for the great pioneer pilot Cecil Grace. This aircraft is conspicuous by its absence from contemporary records and diligent research by the author only makes it evident that no such aircraft existed.

Roe IV Triplane

  The last of A. V. Roe’s primitive triplanes, completed in September 1910, was a single seater structurally similar to its predecessors and powered by a 35 hp Green water-cooled engine, the radiator for which was mounted in the centre section gap. The shortened bottom wing was retained but the wing chord was somewhat reduced. Despite the improved lateral control given by ailerons, the Roe IV triplane reverted to wing warping, effected by rotating a control wheel mounted on a column which moved fore and aft for diving and climbing. The tailplane was triangular in shape and for the first time of the non-lifting monoplane type equipped with movable elevators. The familiar four-wheeled undercarriage of the previous triplanes was also a feature of Roe IV.
  By the middle of 1910 ‘A.V.’ was fast becoming interested in building a biplane, with the result that only one Roe IV was constructed. It was used almost exclusively for instructional work at the Avro Flying School at Brooklands where pupils found it rather sensitive on the controls and more difficult to master than the earlier machines. Needless to say it was broken many times as on October 10, 1910, when, in the words of an onlooker, ‘a pupil rose unsteadily and after 225 yards slowly sideslipped into the sewage farm, completely smashing the starboard mainplane.’ Such incidents were so frequent that they excited little comment and the aircraft structure was so simple that even major damage could often be put right the same day.
  Several famous pilots were trained on the Roe IV triplane, including Hubert Oxley and C. Howard Pixton, the former starting his training with a flourish by attempting to take off down wind without previous experience and nosing over in the sewage farm on October 17, 1910. Pixton, practising figure eights at 200 ft on November 8 for his Royal Aero Club certificate, sideslipped Roe IV into the ground, where it caught fire and suffered extensive damage. Nevertheless the machine was out again on November 17, back in the sewage farm by December 4 and carried Pixton successfully through the tests for his aviator’s certificate on January 24, 1911. It continued to suffer at the hands of trainees such as F. Conway Jenkins, Gordon Bell, R. C. Kemp and Lt W. D. Beatty, until the last mentioned slipped in and badly wrecked it on February 14, 1911. This time the damage took a fortnight to repair and the opportunity was taken to insert a 4 ft extension piece into the fuselage.
  Pixton made the first test flight in the revised Roe IV on March 1 and managed to coax it up to 750 ft. This performance contrasted sharply with the usual 150 ft ceiling associated with this machine. A week later, on March 8, engine trouble compelled R. C. Kemp to abandon the tests for his certificate and soon afterwards (certainly no later than August 1911) the Roe IV was dismantled and replaced at the Avro School by the Type D biplane of superior performance.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company, Brownsfield Mills, Great Ancoats Street, Manchester; and Brooklands Aerodrome, Byfleet, Surrey
   Power Plant: One 35 h.p. Green
   Dimensions:
   Span (upper) 32 ft. 0 in. (bottom) 20 ft. 0 in.
   Length 30 ft. 0 in. (increased to 34 ft. 0 in. February 1911)
   Height 9 ft. 0 in. Wing area 294 sq. ft.
   Weights: Airframe less engine 350 lb. All-up weight 650 lb.
   Production: One aircraft only, completed 9.10, withdrawn from use at Brooklands about 8.11

Avro Type D

  In 1911 A. V. Roe abandoned the triplane configuration and designed a biplane which bore a close resemblance to the Roe IV. It was a two-seater with triangular girder fuselage, twin undercarriage and the same type of cumbersome, triangular monoplane tail. This was replaced almost at once by one of rectangular shape. As on Roe IV, lateral control was by means of wing warping but the passenger seat was placed at the C.G. so that the machine could be flown solo without ballast. Power was supplied by a 35 hp Green, the radiator for which, placed vertically behind the engine at right angles to the direction of flight, distinguished this machine from later aircraft of the same type. It is probable that the engine was that knocked down to A. V. Roe for £67 10s. when the assets of the Scottish Aviation Syndicate were auctioned at Brooklands on December 17, 1910.
  In later years aircraft of this type became known as the Avro Type D even though no reference seems to have been made to Types A, B, or C. These, of course, would have been designations posthumously applied to the early triplanes.
  The first Avro Type D was erected at Brooklands in March 1911 and first flown on April 1 by C. Howard Pixton (who later took Mrs Roe up in it). He declared it stable, viceless and easy to fly, characteristics confirmed by Gordon Bell and effectively demonstrated on April 11 by Lt Wilfred Parke RN who, without having been in an aeroplane before, flew the length of the aerodrome. Numbered 1, it was flown in the Brooklands-Shoreham race by Pixton on May 6, 1911 - the first event in which the Avro entry was not flown by the designer. Pixton lost time at the start because he was flying round in an attempt to win the £500 Manville endurance prize with passenger. He had completed 26 minutes 30 seconds before noticing competitors taking off at the start of the race. He had no map, no cross country experience, and the Type D had never before been flown outside Brooklands Aerodrome. Nevertheless he made a hasty landing to refuel and set off after the others. He lost his way and took three hours for the trip, landing en route at Plumpton Racecourse, seven miles short of his destination. On the way back he spent two days at a flying demonstration at Oakwood, Haywards Heath, returning to Brooklands on Monday May 9 after a very turbulent trip via Dorking. On May 12 he flew the Type D to Hendon in 48 minutes to give a flying display before the Parliamentary Aerial Defence Committee, during which he carried the famous Cdr Sampson RN as passenger and sent A. V. Roe solo in the machine for the first time. Pixton flew home to Brooklands next day and on May 19 made a nonstop flight of 1 hour 30 minutes towards the Manville prize. On June 11 the Type D climbed to a considerable height with the 12 stone Pixton and a 14 stone passenger.
  After a flight at Brooklands in June 1911, Cdr Schwann (later AVM Sir Oliver Schwann KCB, CBE) of the Naval Airship Tender Hermione, bought the Type D for £700. It was despatched by rail to Barrow-in-Furness where the original triangular tailplane was replaced, the wheels removed and the skids lashed directly to a series of float undercarriages designed by Schwann and his associates and built by naval personnel. The drag of the floats was partially offset by repositioning the radiator horizontally on top of the centre section and by covering the rear fuselage with fabric.
  During first taxying trials on August 2 in the 9 ft deep Cavendish Dock on Schwann’s narrow flat bottomed Mk.I floats, the aircraft assumed such a tail-down attitude on the water that the small tail float caused excessive wash. This and the fin were therefore removed and the rudder moved upward along the hinge line to clear the water. Later the rudder was raised still further till the lower edge was in line with the bottom of the fuselage. Maximum speed was only 18 knots and the machine eventually capsized. Report R & M 69 deals at length with Schwann’s further experiments with seven different types of single and twin float undercarriages. Limited success came on November 18, 1911, after the Green Engine Co Ltd had coaxed an extra 10 hp out of the engine by fitting additional open exhaust ports, and float design had reached the Mk.VII stepped type. On that day the Type D lifted on to the step for the first time and left the water rather unexpectedly, reaching a height of 15-20 ft. Schwann was not at that time a qualified pilot and the aircraft fell back into the water and capsized. After salvage and reconstruction, trials were resumed by S. V. Sippe who made the first of a series of short flights at Barrow on April 9, 1912, during which he reported favourably on the feeling of acceleration from the unstick speed of 25 mph to the flying speed of 40 mph. It became the first seaplane ever to take off from British sea water. On April 12 Sippe made two or three circuits of the dock and reached a height of 160 feet. The seaplane was then handed over to the owner who had just qualified as a pilot at the Bristol School on Salisbury Plain. The feasibility of marine aircraft had been proved but the rate of climb of the Type D seaplane was poor due to an increase in all-up weight to 1,000 lb (an accurate figure obtained by weighing the machine in the airship shed at Barrow). Endurance was but 20 minutes - the time taken for the cooling water to boil away, so a 50 hp Gnome rotary was fitted in an attempt to improve the performance, but there are no recorded flights with this engine.
  The sale of the Type D biplane reduced the Avro School to only one aircraft - the Roe IV triplane. Pending delivery of new machines from Manchester, A. V. Roe acquired a secondhand Gnome-engined Farman pusher purchased in Newcastle. The crates housing this relic were too big for railway trucks and travelled south by sea at a cost of £25. This charge contrasted sharply with that for Avro aircraft, which broke down into sections to fit into a single crate, the Manchester-Brooklands rail charge for which was a mere £1 16s. 6d.
  The next Avro aircraft was a modified Type D built to compete in the £10,000 Daily Mail Circuit of Britain Race. It was a sesquiplane with upper and lower spans of 33 and 23 feet, powered by a 60 hp E.N.V. eight-cylinder, water-cooled engine. Like all subsequent machines of the type, its fuselage was increased in length from 26 ft to 28 ft, but it was the only one, apart from the prototype, to be fitted with the large triangular tailplane. Construction took place at Manchester during June 1911 under the watchful eye of the pilot, R. C. Kemp, and first taxying trials were made at Brooklands by A. V. Roe on July 18. First flights made by Kemp later in the day showed the machine to be fast, but the engine overheated and the rate of climb was poor with full load of petrol and oil. Without A. V. Roe’s approval, extensions were hurriedly fitted to the lower wing, making it equal in span to the upper and increasing the wing area by 50 sq ft. After an initial test circuit at 100 ft on July 22, morning of the race, Kemp climbed to 800 ft but during a fairly steep descent at half throttle the extension to the port lower mainplane failed at 150 ft. Although he jerked on full right rudder and full left warp, the machine spun into the ground wingtip first and broke up. Miraculously Kemp stepped unhurt from the wreckage.
  The third Type D, the assembly of which was completed at Brooklands on September 9, 1911, was almost identical with the first but distinguishable from it because drag had been reduced by fitting the radiator in a sloping position behind the engine. Minor differences included straighter front skids, a covered fuselage and no fin. First straight hops were made by F. P. Raynham on September 11 and after adjustments a flight to 600 ft was made on September 17. Although intended as a school machine, it was entered for the Michelin Speed Prize but during his flight to Hendon to compete on September 21, Raynham ran into thick fog. In attempting to ‘press on’ with primitive instruments, he made what may have been the first recorded spin and recovery, afterwards landing at New Barnet to ask his way. Unsatisfactory experiments with a new airscrew, and sagging wing fabric compelled him to give up the attempt. He therefore returned to base, arriving over Brooklands at 1,000 ft on the evening of September 24 and by the end of the month the Type D was in full time use by the Avro School.
  Delivered at Brooklands on September 30, 1911, the fourth Type D was a single-seater but otherwise identical with the equal-span school version, except for the radiator which was fitted vertically behind the engine in line with the direction of flight. The engine was a specially tuned Green giving 45 hp and identified by holes at the base of the cylinder walls which improved scavenging. After some trouble with slack fabric, satisfactory first flights on October 12 again raised Raynham’s Michelin hopes and although he reached 1,000 ft with 5 hours’ fuel (13 gallons) during a practice flight two days later, bad weather on October 15, last day of the competition, ruined his chances. With an eye on the Michelin long distance prize, he coaxed the machine off on October 18 with 8 hours’ fuel (24 gallons) but the attempt came to an abrupt end when the machine forced landed in the sewage farm with an iced-up carburettor on October 27, only three days before the closing date.
  The fifth Type D was an improved sesquiplane version generally similar to, and having the same dimensions as, the ill-fated Circuit of Britain machine. The engine was a 35 hp Green.
  The sixth machine was a single-seater powered by a new 35 hp five-cylinder Viale air-cooled radial which had been delivered to A. V. Roe on September 30, 1911. The installation was done by Maurice Ducrocq (British concessionaire for Viale engines) and his apprentice Jack Alcock. Work was completed on October 6 but it was not until November 20 that first flights were made by F. P. Raynham. The Viale-powered Type D proved very manoeuvrable and flew strongly in the hands of a number of school pilots. On December 6 Raynham used it for joyriding by removing the fuselage petrol tank to make room for a passenger to kneel facing him. On December 27 Wilfred Parke climbed the machine to 2,500 ft over Addlestone as a prelude to his ‘Superior Brevet’ tests and S. V. Sippe gained his Aviator’s Certificate on it on January 8, 1912. During an attempt to fly to Oxford as part of his tests on January 13, Parke followed the Thames until poor visibility forced him down at Abingdon where he broke two bracing wires and damaged the undercarriage and mainplanes. On the following morning the machine was dismantled in 65 minutes and temporarily stored in a local garage. The ‘broken parts’ of the machine were subsequently sent to the Avro works at Manchester, arriving there on February 16, 1912. The necessary repairs were reportedly almost complete by the end of the same month but there is no record of the aircraft ever having flown again and its Viale engine was installed in the Avro Type F cabin monoplane in the following April.
  It is believed that only seven Type D biplanes were produced at the Manchester works. Advertisements making a special offer of 12 Type Ds at a reduced rate of £400 each during October and November 1911 can only be regarded as a publicity stunt. There is no evidence that any orders were placed.
  In October 1912 the Avro School moved from Brooklands to the new aerodrome at Shoreham-by-Sea, Sussex, and became the Avro Flying School (Brighton) Ltd with A. E. Geere as CFI. Last noteworthy flights before the transfer were made in mid-August by Wilfred Parke in the old sloping radiator Type D to Staines, Ripley, Hounslow Heath and Walton. The machine was used for instruction at Shoreham during 1913 and became well known along the South Coast as did the school’s 45 hp Green engined Type D, Type D with 50 hp Isaacson seven-cylinder radial, and the Avro Type E prototype described later.
  The Isaacson-engined machine was the seventh and apparently final Type D manufactured. Recorded in the Avro works’ log as being under construction on October 31, 1912, the airframe was complete by November 29, 1911, though the engine was not delivered to the factory until December 4, 1912. Its first flight date is not recorded.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company, Brownsfield Mills, Great Ancoats Street, Manchester; Brooklands Aerodrome, Surrey; and Shoreham Aerodrome, Sussex
   Power Plants:
   One 35 h.p. Green
   One 45 h.p. Green
   One 35 h.p. Viale
   One 50 h.p. Isaacson
   One 60 h.p. E.N.V. Type F
   Dimensions, Weights and Performances:
   Standard Seaplane Sesquiplane
   Span, upper 31 ft. 0 in. 31 ft. 0 in. 33 ft. 0 in.
   Span, lower 31 ft. 0 in. 31 ft. 0 in. 23 ft. 0 in.
   Length 28 ft. 0 in.(*) 26 ft. 0 in. 28 ft. 0 in.
   Height 9 ft. 2 in. - 9 ft. 2 in.
   Wing area 310 sq. ft. 310 sq. ft. 279 sq. ft.
   All-up weight 500 lb. 1,000 lb. 550 lb.
   Speed 45-50 m.p.h. 40 m.p.h. -
   Range 100 miles(**) - -
   (o)Prototype 26 ft. 0 in. (**)With Viale engine.

   Production:
   No. 1 Prototype, 35 h.p. Green, transverse radiator, first flown 1.4.11, converted to seaplane, last mentioned 4.12;
   No. 2 Circuit of Britain machine, E.N.V. engine, first flown 18.7.11, crashed at Brooklands 22.7.11;
   No. 3 School machine, 35 h.p. Green, slanting radiator, first flown 11.9.11, withdrawn from use at Shoreham 5.14;
   No. 4 Single seater, 45 h.p. Green, fore-and-aft radiator, first flown 12.10.11, withdrawn from use at Shoreham 5.14;
   No. 5 Improved sesquiplane, believed that advertised for sale at Shed 4, Brooklands, 5.12 and that reported scrapped near the petrol store 12.12;
   No. 6 School machine, Viale engine, first flown 20.11.11, almost certainly re-engined with 50 h.p. Isaacson, withdrawn from use at Shoreham 5.14
   No. 7 School machine, Isaacson engine, withdrawn from use at Shoreham 5.14.

The Burga Monoplane

  In 1912 A. V. Roe and Company built a shoulder-wing monoplane to the designs of Lt Burga of the Peruvian Navy, who wished to try out some highly original ideas on aircraft control. The machine was constructed at Brownsfield Mills at the same time as the Avro Type E prototype and used the same tail and undercarriage, but the fuselage was much slimmer and the engine a 50 hp Gnome rotary.
  Rectangular monoplane wings were wire braced to strong points on the undercarriage and to a pylon built over the fuselage. There was no wing warping, lateral control being obtained by two ‘rudders’, one above and one below the fuselage, working in opposite directions. The design made provisions for wings of varying camber which fitted at varying angles of incidence to give the machine any desired performance.
  Construction of the Burga at Brownsfield Mills was evidently undertaken on an intermittent basis as other work allowed. It was first mentioned in the Works Log in February 1912 but by the end of March had been dismantled and removed to a cellar, ending up the following month suspended from the boiler house roof. There it remained until June 3 when it was re-erected and the left wing doped in time for the machine to be inspected by visiting VIPs the following day. Work started on the engine in July and the top wing bracing was finished in August. A further two months elapsed before the whole machine was completed and it was finally dispatched from the factory on October 15, 1912.
  Lt Burga took a shed at Shoreham where the machine was test flown on November 20, 1912, by H. R. Simms. The mainplanes fitted were those best suited for maximum speed and the pilot reported that it was certainly fast and had a good rate of climb. Further taxying trials were made by H.S. Powell in the following month shortly before the machine was seriously damaged in an accident. This resulted in the Burga monoplane being returned to the Avro Works at Manchester in January 1913 for repair and it was not heard of again.


   Manufacturers: A. V. Roc and Company, Brownsfield Mills, Great Ancoats Street, Manchester; and Shoreham Aerodrome, Sussex
   Power Plant: One 50 h.p. Gnome
   Dimensions: Length 29 ft. 0 in.
   Production: One aircraft only, first flown at Shoreham 20.11.12

The Duigan Biplane

  John R. Duigan was an Australian who designed and built a Farman-type biplane at Mia Mia, Victoria, in 1910 and flew it before a very large crowd at Bendigo Racecourse, Melbourne, on May 3, 1911. A series of accidents convinced Duigan that he needed proper flying instruction and some weeks later he sailed for England, arriving in August 1911. Two months elapsed before he joined the Avro School at Brooklands, having by then already placed an order for a private Avro aeroplane. In November he went to Manchester to see it built.
  The machine was a two-seat, dual control biplane, similar to Type D but fitted with a square rudder, steel framed tailplane and square instead of triangular section fuselage. The seats were arranged so that the occupants’ heads were raised just above the padded rim of an elliptical opening and celluloid windows were provided in the floor to give downward view. Following current Continental practice, Roe tried a newer wing section having ‘Phillips entry’ whereby the chord line of the wing was horizontal in level flight. Wing warping was employed for lateral control and wing spars were of English ash with poplar ribs, rounded wingtips being formed from rattan cane. As usual, the whole machine was built in sections, easily dismantled for transport, the fuselage consisting of two halves bolted together behind the rear cockpit. The engine was a 40 hp horizontally opposed Alvaston driving an Avro airscrew of kauri pine and cooled by large spiral tube radiators on each side of the front cockpit.
  The undercarriage was a complete departure from normal Avro practice, incorporating a Nieuport-type leaf-spring axle and centre skid with bracing wires to flatten long grass and prevent nosing over. This type of undercarriage proved so successful that in modified form it was used on Avro aeroplanes for a generation. First straight hops were made by Duigan at Huntingdon Racecourse flying ground early in December 1911 but in spite of experiments with different airscrews the machine was very loath to leave terra firma. Considering it advisable to return to the Avro fold, Duigan took the machine to Brooklands where a 35 hp E.N.V. engine was fitted and he met with more success. On March 10 several long straight flights were made but the aircraft was sadly underpowered and only flyable in good weather. Duigan then made and fitted an airscrew of his own design and working as his own mechanic, tuned the E.N.V. engine to such good effect that on April 13 he succeeded in flying several times round Brooklands track. On April 19 he flew figure eights at 300 ft and on April 20 successfully completed tests for his Aviator’s Certificate (No.211), the aircraft having completed four hours in the air up to that date entirely without damage. Passenger flights, not so successful on low power, were confined to straights within Brooklands track. Duigan’s best solo flight in his machine, consisting of an hour’s circuits over Addlestone at an altitude of 400-600 ft, was made on April 30. His final recorded flight was on May 15.
  Having achieved his objectives, Duigan returned home. There he built a very similar machine to the Avro which crashed on its first flight on February 17, 1913. His British aeroplane was put up for sale with engine for £380 but was almost immediately reduced to £180, no doubt because the engine had been sold separately. The airframe was purchased by the Lakes Flying Company and it was delivered to Windermere on June 4, 1912. Here it was rebuilt as the centre float seaplane Sea Bird which H. Stanley Adams flew off the lake for the first time on August 28, 1912. The company entirely redesigned the front end of the fuselage to accept a 50 hp Gnome rotary, the upper half of which was cowled and gave a cocked-up appearance to the nose. New three-bay, warping mainplanes of Eiffel 12 section and 8-5 aspect ratio were also fitted. The machine proved much faster than the old Avro-built Water Bird and after it has been fitted with an improved twin float undercarriage, carried large numbers of holiday makers during 1912-13.
  At the end of 1912 the machine was tested with an amphibious undercarriage but trials came to an end on December 18, 1912, when Sea Bird piloted by Lt J.F.A. Trotter was caught by a gust of wind and the lower port wing struck the water. In January 1915 the Lakes Flying Company was taken over by the Northern Aircraft Company Ltd and thereafter the machine was generally referred to as the Avro Biplane Tractor. It was equipped with dual control soon after and at the beginning of June was fitted with new floats. Unfortunately, pupil R. Buck took off in the Avro for his Vol-plane test on June 5 unaware that the latter had altered the centre of gravity. On switching off the engine to begin his glide approach, Buck failed to lower the nose sufficiently and the machine stalled at 300 ft, crashing into the lake tail first. Miraculously Buck was unhurt but the Sea Bird was destroyed.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company, Brownsfield Mills, Great Ancoats Street, Manchester; and Brooklands Aerodrome, Byfleet, Surrey.
   Rebuilt by The Lakes Flying Company, Cockshott, Lake Windermere, Westmorland
   Power Plants:
   (Duigan)
   One 40 h.p. Alvaston
   One 35 h.p. E.N.V. Type D
   Dimensions:
   (Duigan) Span 34 ft. 0 in. Chord 4 ft. 6 in.
   Height 10 ft. 6 in. Wing area 350 sq. ft.
   Performance:
   (Duigan) Speed 40 m.p.h.

   Production: One aircraft only, first flown 2.12; converted into the Lakes Sea Bird 10.12, crashed at Windermere 6.15



Avro 500 (Type E)

  The first War Office military aircraft specification, issued in 1911, called for a two seater to carry a 350 lb load in addition to essential equipment and have an endurance of 4 1/2 hours, initial rate of climb of 200 ft/min, maximum speed 55 mph, ability to maintain 4,500 ft for one hour, and be capable of delivery to Salisbury Plain in a crate. Competing firms had only nine months in which to design, build and test.
  A. V. Roe and Company met this specification by building a new two seat biplane, very similar in design and construction to the previous year’s Duigan machine. The built-up box-girder fuselage was again of square section, fabric covered in the rear and metal clad forward. It was more streamlined than the Duigan with pilot and passenger seated at the widest part with their heads protruding through padded openings in the top. Small celluloid panels were again provided in the floor to give downward vision. The mainplanes used ash spars and an improved, double-surfaced section covered with Pegamoid fabric. They were detachable in three sections for ground transport. The undercarriage was of the Duigan type with centre skid and leaf-spring axle, the tail being carried on a rubber-sprung skid.
  A 60 hp E.N.V. watercooled engine was mounted on the top longerons and drove a 10 ft Avro airscrew. The main fuel tank was in front of the passenger and twin gravity tanks were fixed to the centre section struts. Known originally as the ‘Military Biplane’, but in later years as the Type E prototype, the machine was first flown at Brooklands by Wilfred Parke on March 3, 1912. It was obvious from the outset that this was no ordinary aircraft but one with that rare quality, a reserve of power. This encouraged its entry for the Mortimer Singer prize. Test flying took but a few days, during which it was promptly dubbed Elinor Glyn (after a well-known novelist of the period) and on March 23 Parke climbed to 1,000 ft in under six minutes and 2,000 ft in 13 minutes with a heavy passenger (R. L. Charteris).
  Cooling was by spiral tube radiators on each side of the front fuselage, augmented by two smaller units on the centre section struts on each side of the passenger’s head. On April 20 Parke suffered partial engine failure when taking off for Hendon to compete for the prize. The hurried landing ripped off undercarriage and mainplanes and when the aircraft rolled on its side the auxiliary radiators folded over the front cockpit and engineer W. H. Sayers had to be extricated through a hole cut in the side. In the interest of future passengers the machine was rebuilt with only the lower radiators fitted. Parke successfully piloted the machine through Farnborough trials in June 1912 after which it returned to Brooklands to become a flying testbed for the new 60 hp A.B.C. engine. First straight hops with this power unit were made by F. P. Raynham on August 31 but it was not until October 18, when several engine and airframe adjustments had been made, that it flew strongly in the hands of the A.B.C. representative R. L. Charteris. In 1913 the E.N.V. engine was reinstalled and the aircraft sent to Shoreham and there flown by experienced pilots of the Avro School, such as H. R. Simms and H. S. Powell. On June 29, 1913, pupils were allowed to fly it for the first time but in the afternoon it stalled on a turn, crashed and was destroyed by fire. Pilot R. N. Wight received fatal injuries, the first ever in an Avro aircraft.
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SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company (reconstituted as A. V. Roe and Co. Ltd., 11.1.13), Brownsfield Mills, Great Ancoats Street, Manchester (moved to Clifton Street, Miles Platting, Manchester, 4.13); and at Shoreham Aerodrome, Sussex
   Power Plants:
   (Type E prototype) One 60 h.p. E.N.V. Type F
   One 60 h.p. A.B.C.
   Dimensions:
   Span 36 ft. 0 in. Height 9 ft. 9 in.
   Length
   (Type E prototype) 30 ft. 6 in.
   Wing area 330 sq. ft.
   Weights:
   (Type E prototype) Tare weight 1,100 lb. All-up weight 1,650 lb.
   Performance:
   (Type E prototype)
   Maximum speed 50 m.p.h.
   Initial climb 170 ft./min. Endurance 6 hours

   Production:
   Type E
   Prototype only, first flown at Brooklands 3.3.12, destroyed by fire at Shoreham 29.6.13

Avro 500 (Type E)

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  Although he had created a remarkable aeroplane, A. V. Roe was not altogether satisfied. He therefore built an almost identical machine and fitted the 50 hp Gnome seven-cylinder rotary taken from the superannuated Avro School Farman when it was dismantled in November 1911. The Gnome, only a fraction of the weight of other engines of similar power, gave the machine a much enhanced performance and during first flights at Brooklands by Parke on May 8, 1912, the machine reached 2,000 ft in five minutes. The next day he flew 17 miles to Laffan’s Plain in 20 minutes and completed all official trials the same afternoon. Officialdom was impressed and after some haggling over price, the War Office bought it and ordered two others with dual control. One of these is said to have been tested to destruction under ground load, but it is now clear that the Avro 500 in question was merely proof loaded as part of the acceptance trials.
  A. V. Roe always regarded the Gnome powered Type E as his first really successful aeroplane. Dismissing all previous machines as mere experiments he gave it the imposing type number 500, first of the Avro series which continued in use throughout the firm’s existence.
  Wilfred Parke first flew the second Avro 500 at Brooklands on June 5, 1912, and delivered it to Farnborough in 23 minutes later in the day. Although so many Avro aircraft had first seen the light of day in Manchester, the inhabitants of that city had not at that time seen one in the air. To remedy this the third Army machine was ‘borrowed’ on June 28, taken from the factory to Eccles Cricket Ground and next day flown over Chorlton by Parke. Flights were made from Old Trafford over the Docks on the following day and from Fallowfield on July 5. After minor repairs the machine was then flown to Brooklands for normal flight test by Parke (with Gordon Bell as passenger) on July 19 before delivery by Raynham on July 22. The three Avro 500s joined the strength of the Central Flying School, Upavon, with serial numbers 404, 405 and 406. They were flown by pilots who later became famous, such as Maj Brooke-Popham (later Air Chief Marshal Sir Robert Brooke-Popham, Governer of Kenya) and Lt-Col Cook RA who made a notable flight to Portsmouth in 404 on August 8, returning via Lee-on-Solent (50 miles) in 40 minutes on August 17. The Avro 500 rapidly established itself as the best available trainer, resulting in a further order for four two-seaters in November 1912 and another for five single-seaters to equip No. 3 Squadron, Netheravon, in January 1913. The latter were given the Avro type number 502 though in military service they were simply known as the Avro Type Es in order to distinguish them from the two-seat Type E (Avro 500).
  Years of endeavour were being rewarded. To A. V. Roe fell the honour of escorting HM King George V round the second machine of the two-seater batch at the Olympia Aero Show of February 14-22, 1913. With total orders at the dozen mark the firm had become sufficiently stable financially to re-form as a limited company on January 11, 1913, and to move into larger premises at Clifton Street, Miles Platting, Manchester, in the following April. War Office orders were completed in June 1913 (the penultimate single-seater was tested at Shoreham by F. P. Raynham on June 12). The Air Department of the Admiralty also received two Avro 500s, both of which were stationed at Eastchurch. The first, 41, was delivered in March 1913 and the second, 150, in February of the following year.
  During the short Service life of the Avro 500, several important modifications were made. The prototype had no tail skid and depended on a steel shoe screwed to the bottom of the rudder. It was a weak arrangement and the rudder was redesigned to absorb landing shocks by sliding vertically up the kingpost against the action of a coiled spring. By mid-1913 this still somewhat hazardous system had been abandoned in favour of an ordinary bungee-sprung tail skid and the now-famous comma-shaped Avro rudder. Lateral control on all War Office Avro 500s and Avro 502s was by wing warping but modified outer wing panels incorporating inversely tapered ailerons on top and bottom wings were fitted later. At least 406 was further modified with constant chord ailerons, while in several instances the looped wing tip skids were replaced by braced bamboo rods with, or without, a small wheel at the tip.
  A few machines remained in commission throughout the early years of the First World War and one was locally re-engined at Chingford with a 100 hp Gnome fourteen-cylinder rotary.
  There were at least three other Avro 500s in addition to War Office and Admiralty machines. The first, of the sprung rudder type, was built for the Portuguese Government and paid for by public subscription. Despatched to Lisbon in September 1912 in charge of H. V. Roe, Copland Perry (pilot) and W. H. Sayers (engineer), it was unloaded on October 7 and conveyed by bullock cart to the flying ground at Belem. It was erected and flown on successive days, after which trial flights were made up the Tagus to Lisbon with the name Republica in large red letters on the fuselage and in green under the mainplanes. The machine was handed over to the Minister of War before 20,000 people on October 16 but the next day Perry just failed to reach the aerodrome when an exhaust valve on the Gnome jammed open. He put the Avro down gently in shallow water from which it was salvaged without damage, cleaned down, greased and stored for the winter.
  The best known of all Avro 500s was probably that flown by F. P. Raynham to the Burton-on-Trent Meeting of August 2-5, 1913, during which he carried numerous passengers and won the quick starting and cross country races. As if to underline the fact that this was no ‘stick and string’ freak, Raynham flew the machine south to Brooklands after the meeting and on August 9 raced it from scratch into second place in the six laps speed race at the Hendon August Meeting. Raynham then became so fully engaged in demonstrating the new Avro 504 prototype that the faithful 500 languished at Brooklands until he was free to give dual instruction to H. V. Roe and C. F. Lan-Davis. The latter bought the machine in December 1913 and gained his Aviator’s Certificate on it on March 24, 1914. He first kept the machine at Brooklands but it was later based at Hendon where Lan-Davis fitted an elaborate array of instruments. He also attempted to mass balance the elevator by fitting broomsticks which projected forward at each end.
  The other ‘civil’ Avro 500, delivered Brooklands-Hendon by F. P. Raynham on January 22, 1914, was used for display and instruction by J. Laurence Hall whose name appeared large on the fuselage. Two months later Hall succeeded in looping the machine to show that standard British aircraft were quite as manoeuvrable as the special lightweight French machines of the period. He flew hundreds of trouble-free hours in it and made numerous cross country flights including a 45 minute trip from Shoreham to Hendon with a lady passenger on July 14. An order for four Avro 500s by the Royal Aero Club was frustrated by the outbreak of the First World War but the Hall machine continued in instructional use at Hendon until commandeered by the War Office in September 1914 and allocated the RFC serial 491.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company (reconstituted as A. V. Roe and Co. Ltd., 11.1.13), Brownsfield Mills, Great Ancoats Street, Manchester (moved to Clifton Street, Miles Platting, Manchester, 4.13); and at Shoreham Aerodrome, Sussex
   Power Plants:
   (Avro 500) One 50 h.p. Gnome
   One 100 h.p. Gnome
   Dimensions:
   Span 36 ft. 0 in. Height 9 ft. 9 in.
   Length
   (Avro 500) 29 ft. 0 in.
   Wing area 330 sq. ft.
   Weights:
   (Avro 500) Tare weight 900 lb. All-up weight 1,300 lb.
   Performance:
   (Avro 500)
   Maximum speed 61 m.p.h.
   Initial climb 440 ft./min.

   Production:
   Avro 500
   (i) To War Office contract March 1912
404 - first flown at Brooklands 8.5.12, delivered to Farnborough 9.5.12, thence to CFS Upavon
405 - first flown at Brooklands 5.6.12, delivered to Farnborough 5.6.12, thence to CFS Upavon
406 - first flown at Manchester 28.6.12, delivered to Farnborough 22.7.12, thence to CFS Upavon
   (ii) To War Office contract December 1912
430, 432, 433, 448 - delivered to CFS Upavon 20.1.13, 24.2.13, 20.3.13 and and 17.4.13 respectively
   (iii) To Admiralty contract 1913
41 - delivered to Eastchurch 3.3.13, to Hendon 9.14
150 - delivered to Eastchurch 23.2.14
   (iv) Other machines
1. For the Portuguese Government - handed over in Lisbon 10.10.12, named Republica
2. Demonstrator, first flown 7.13, sold to C.F. Lan-Davis 12.13, awaiting more powerful engine at Hendon 8.14, believed to have been the Avro 500 that was in RNAS service at Hendon from October 1914 and carried the military serial 939.
3. To J. Laurence Hall, Hendon 22.1.14, commandeered 9.14 and allotted RFC serial number 491.

   Avro 502
   (i) To War Office contract January 1913
285, 288, 289, 290, 291 - delivered to No.3. Squadron, Netheravon, 3.4.13, 30.4.13, 14.5.13, 28.5.13, 21.6.13 respectively, all to No.5 Squadron by January 1914 and to the CFS by September 1914

Avro Type F

  In the spring of 1912 A. V. Roe’s fertile mind conceived the idea of an enclosed aeroplane affording the occupants complete protection from the elements. He straightway designed two such machines, the first of which was a single seat, mid-wing monoplane known as the Type F.
  Structurally similar to the Avro 500, it used the same undercarriage, tail unit and small rudder (this time linked to a steerable tail skid), but there the similarity ended. The box-girder fuselage was of streamlined shape built up from four wooden longerons and cross struts, reinforced by triangular plywood stiffeners in each bay and braced internally with piano wire. By unlacing the fabric half way along the rear fuselage to expose steel jointing plates, the fuselage could be taken apart quite easily to facilitate packing. Its maximum width was only 2 ft but there was sufficient depth for the pilot to sit wholly inside with a somewhat restricted view through a number of celluloid windows. Entry was through a sheet aluminium trapdoor in the roof and large circular holes were provided in each side through which the head could be thrust when flying in poor visibility. Fuel and oil tanks were situated inside the fuselage, remote from the engine to reduce risk of fire.
  The mainplane, constructed in two halves round a built-up front spar, was mounted on the centre line of the fuselage and braced by wires to a stout kingpost under the fuselage and to a pylon of steel tubes on top. Lateral control was by wing warping.
  The Type F monoplane was erected at Brooklands in April 1912 and Wilfred Parke made the first take-off on May 1, climbing the machine steeply on half throttle. It was the first flight in the world by an aeroplane with a totally enclosed cockpit. Critics predicted that oil thrown back by the 35 hp Viale five cylinder radial engine would completely obscure the pilot’s vision but this proved not to be the case. It was a carefully maintained engine well known to Parke, being that taken from the Type D school machine which he had flown from Brooklands to Abingdon in the previous January. First circuits were made on May 3 and test flying continued until May 17 when, during a flight over Chertsey, 1,000 ft was reached for the first time. On May 25 it was decided to show the machine at Hendon but the engine failed soon after take-off and in the ensuing forced landing at Weybridge, Parke hit a fence and turned over. There was little damage and the Type F was dismantled by four men in 25 minutes for return to the workshops.
  For some months the machine languished at Brooklands until taken out by R. H. Barnwell on September 13. After one or two straight hops, the front part of the skid was broken in landing and the aircraft turned over, suffering serious damage in the process. Barnwell was unhurt but it is evident that the Type F did not fly again.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company, Brownsfield Mills, Great Ancoats Street, Manchester; and Brooklands Aerodrome, Byfleet, Surrey
   Power Plant: One 35 h.p. Viale
   Dimensions:
   Span 28 ft. 0 in. Length 23 ft. 0 in.
   Wing area 158 sq. ft.
   Weights: Tare weight 550 lb. All-up weight 800 lb.
   Performance: Maximum speed 65 m.p.h. Initial climb 300 ft./min.
   Production: One aircraft only, first flown at Brooklands 1.5.12, damaged beyond repair at Brooklands 13.9.12. Engine preserved at the Science Museum, London, and the rudder by the Royal Aero Club.

Avro Type G

  A. V. Roe’s second cabin aeroplane was a two seat biplane designed specifically for the Military Aeroplane Competition of August 1912, and today historically important as the world’s first cabin biplane. Very similar structurally to the Type F, the fuselage filled the whole mainplane gap and was again very narrow with a maximum beam of 2 ft 3 in tapering to only 15 in at the front end. This was made possible by the use of a slim inline engine mounted on steel bearers and enclosed in louvred cowlings with the main exhaust taken over the roof. As on the Type E prototype, cooling was by means of spiral tube radiators on each side of the cabin, entry to which was through triangular doors hinged to slanting struts in the sides of the fuselage. Mainplanes, undercarriage and tail unit were identical with those of the Avro 500. Once again there was no vertical fin and the steel shod rudder also acted as tail skid. Lateral control was by wing warping with a maximum warp at the tip of 18 in.
  Two Type G biplanes were laid down. One with a 60 hp Green engine to be flown by Wilfred Parke with competition number 6 and a second, numbered 7, for R. L. Charteris of the All-British Engine Co Ltd with a 60 hp A.B.C. eight-cylinder engine. Unfortunately this A.B.C. engine was not ready in time and as a matter of expediency No.7 was completed with the Green engine in place of No.6.
  There was no time for test flying and the aeroplane was delivered in a crate direct to the competition ground at Larkhill on Salisbury Plain and there flown for the first time by Wilfred Parke. On August 7, 1912, he took off at the start of the 3 hours endurance test but after half an hour turbulent conditions compelled him to give up. Hurriedly landing down wind, he overturned and so damaged the machine that it had to be sent back to Manchester for repair. Exactly a week later on August 14, the machine returned, no doubt incorporating many components of the unfortunate No.6. During the resumed trials Parke demonstrated the machine’s all-weather qualities by flying in a rainstorm for 37 minutes and for half an hour in a wind of 40 mph.
  At 6.04 a.m. on Sunday August 25, 1912, Parke again started on the endurance test carrying Lt Le Breton as passenger. Just after 9 a.m. he commenced a series of steep dives to relieve the monotony and in so doing spun off a turn, but Parke’s cool head and analytical mind were equal to the situation and he soon discovered that if the stick were central, recovery was possible by applying full opposite rudder. He was the second pilot to survive a spin but the first to do so before competent observers. In the ensuing discussions he gave a lucid account of what had taken place and today ‘Parke’s Dive’ is recognised as an important milestone in the development of flying techniques. Later in that eventful day H. V. Roe flew as passenger to Upavon and became the first person to type a letter in an aircraft in flight.
  The Type G cabin biplane was an easy winner in the assembly test in a time of 14 1/2 minutes compared with the 9 hours 29 minutes of the Farman biplane and although the accident left insufficient time for the compilation of all the required data, the Avro company was awarded £100 for attempting all the tests. The Type G failed to secure a major award because the initial rate of climb was poor (9 min 30 sec to reach 1,000 ft).
  F. P. Raynham flew the machine home to Shoreham on October 11 but it had been in the open for so long that both engine and rigging needed attention. He therefore took the machine to Brooklands for adjustments on October 21 in 45 minutes and next day made an attempt to win the British Empire Michelin endurance prize. A broken water connection ended the flight after 3 1/2 hours but on October 24 he established a duration record for all-British aeroplanes with a time of 7 hours 31 minutes. Competing against Harry Hawker in the Sopwith Wright biplane, Raynham flew round Brooklands all day with the Green engine throttled right back to conserve fuel until forced to land through shortage of oil. His record stood for only an hour as Hawker went on to establish a new record of 8 hours 23 minutes and win the £500 prize. The Type G biplane was afterwards flown back to Shoreham where it was last heard of in February 1913 hangared with the Type D biplanes of the Avro School.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company, Brownsfield Mills, Great Ancoats Street, Manchester; and Shoreham Aerodrome, Sussex
   Power Plant: One 60 h.p. Green
   Dimensions:
   Span 35 ft. 3 in. Length 28 ft. 6 in.
   Height 9 ft. 9 in. Wing area 335 sq. ft.
   Weights: Tare weight 1,191 lb. All-up weight 1,792 lb.
   Performance:
   Maximum speed 61.8 m.p.h. Initial climb 105 ft./min.
   Range 345 miles
   Production: One aircraft only, second machine not completed

Avro 501 and Avro 503 (Type H)

  The choice of Shoreham as the Avro company’s new flying ground when it moved from Brooklands in the autumn of 1912 was largely the result of Cdr Schwann’s successful waterborne experiments and Avro’s awakening interest in seaplanes. It was an ideal site with Shoreham Harbour close at hand and it was from the adjacent River Adur that the Avro Type H seaplane made its first take-off. Construction of this machine followed tests on Windermere by H. Stanley Adams in January 1913 with the Avro 501 which, apart from a considerable strut-braced top wing overhang, was similar to an enlarged float-equipped Avro 500. Built at Brownsfield Mills in November 1912 and powered by a 100 hp Gnome, the Avro 501 first flew as an amphibian with a sprung central float designed by O. T. Gnosspelius, 15 ft long and 7 ft wide from which projected three small wheels, two in the rear and one forward. With so narrow a float an aircraft with a wing span of 47 ft 6 ins could be expected to heel over when steerage way was lost, and for this reason small wing tip floats were fitted and inclined to sit squarely in the water. This arrangement proved unsatisfactory and Gnosspelius replaced it with a twin float unit without wheels which made the aircraft sufficiently seaworthy to interest the Admiralty, to whom it was eventually delivered in the Isle of Grain. In the light of experience at Barrow, the airscrew leading edges were sheathed with brass to prevent damage from flying spray and the tail float was bolted directly to the old-style sprung rudder for steering on the water.
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  The float undercarriage of the old Avro 501 having proved far too heavy, the Admiralty agreed to accept it as a landplane. A. V. Roe thereupon devised a two-wheel, twin-skid undercarriage but the track was still too narrow to support the aircraft vertically at rest and stout wing tip skids were necessary. In land-plane form, with large inversely tapered ailerons replacing the constant chord units, the Avro 501 was so quaint a structure that it soon earned the name ‘Rickety Ann’. After delivery to Eastchurch it had to be lightened and several airscrews tried before F. P. Raynham could complete the acceptance tests. Bearing naval serial 16 it was flown to Shoreham on June 2, 1913, by Raynham with Lt Seddon as passenger.
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SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company (reconstituted as A. V. Roe, and Co. Ltd. 11.1.13), Brownsfield Mills, Great Ancoats Street, Manchester (moved to Clifton Street, Miles Platting, Manchester 4.13); and Shoreham Aerodrome, Sussex
   Power Plant: One 100 h.p. Gnome
   Dimensions, Weights and Performances:
   Avro 501 seaplane
   Span (upper) 47ft. 6 in.
   Span (lower) 39ft. 6 in.
   Length 33ft. 0 in.
   Height 12ft. 6 in.
   Wing area 478 sq. ft.
   Tare weight 1,740 lb.
   All-up weight 2,700 lb.
   Maximum speed 55 m.p.h.*
   *Landplane 65 m.p.h.

   Production:
   Avro 501 seaplane, first flown on Windermere 1.13, converted to landplane serial 16, still airworthy in 1914

Avro 501 and Avro 503 (Type H)

  The choice of Shoreham as the Avro company’s new flying ground when it moved from Brooklands in the autumn of 1912 was largely the result of Cdr Schwann’s successful waterborne experiments and Avro’s awakening interest in seaplanes. It was an ideal site with Shoreham Harbour close at hand and it was from the adjacent River Adur that the Avro Type H seaplane made its first take-off. Construction of this machine followed tests on Windermere by H. Stanley Adams in January 1913 with the Avro 501 which, apart from a considerable strut-braced top wing overhang, was similar to an enlarged float-equipped Avro 500. Built at Brownsfield Mills in November 1912 and powered by a 100 hp Gnome, the Avro 501 first flew as an amphibian with a sprung central float designed by O. T. Gnosspelius, 15 ft long and 7 ft wide from which projected three small wheels, two in the rear and one forward. With so narrow a float an aircraft with a wing span of 47 ft 6 ins could be expected to heel over when steerage way was lost, and for this reason small wing tip floats were fitted and inclined to sit squarely in the water. This arrangement proved unsatisfactory and Gnosspelius replaced it with a twin float unit without wheels which made the aircraft sufficiently seaworthy to interest the Admiralty, to whom it was eventually delivered in the Isle of Grain. In the light of experience at Barrow, the airscrew leading edges were sheathed with brass to prevent damage from flying spray and the tail float was bolted directly to the old-style sprung rudder for steering on the water.
  Also powered by a 100 hp Gnome, the Type H (later known as the Avro 503), was a slightly larger version of the Avro 501 but with less mainplane overhang and no inclined struts. Following standard Avro practice, the new seaplane was built with an eye to quick dismantling and was constructed round a 9 ft centre section to which were bolted fuselage, undercarriage and outer wing panels. The upper mainplane, 3 ft greater in span than the lower, was fitted with large inversely tapered ailerons but none was fitted to the lower wing. Two-step, internally sprung floats, 14 ft long and 2 ft 6 in wide, set at a track of 6 ft 6 in, were covered with rubberised material and attached to the aircraft by 14 tubular steel struts bound with varnished fabric.
  Such was his confidence in the Type H that F. P. Raynham made the first take-off from the Adur in sea mist on May 28, 1913, carrying passenger Jack (later Sir John) Alcock, two hours’ fuel and an anchor. The aircraft became airborne after a run of only 60 yards and cleared the adjacent railway bridge by 100 ft. Next day, again carrying the future conqueror of the Atlantic, Raynham made a first landing on the open sea outside Volk’s seaplane hangar opposite Paston Place, Brighton. A float was damaged on take-off so a landing was made in Shoreham Harbour where the aircraft was hastily beached. After some local strengthening of the nose of each float the machine was out again on June 12 and two days later Raynham made an hour’s demonstration flight over Brighton carrying Lt J. W. Seddon RN, Inspector of Naval Aircraft. Despite the weight and drag of the floats, the Type H climbed to 1,300 ft in 5 minutes.
  The Avro 503 was then flown by Capt Schultz, a German naval officer who had made several visits to the works while it was under construction, and before the month was out the machine was purchased by the German Government, dismantled and packed for shipment. Flown by Lt W. Langfeld it became on September 3, 1913, the first aircraft to cross the 40 miles of North Sea from Wilhelmshaven to the Island of Heligoland, a successful return trip to Cuxhaven being made on September 15. An Avro 503 seaplane was also ordered by the Peruvian Government but the outbreak of the First World War prevented delivery and it is believed to have been turned over to the British Admiralty.
  Three other 100 hp Gnome-powered Avro 503s were built - all to Admiralty order for use by the Royal Naval Air Service. The float undercarriage of the old Avro 501 having proved far too heavy, the Admiralty agreed to accept it as a landplane. A. V. Roe thereupon devised a two-wheel, twin-skid undercarriage but the track was still too narrow to support the aircraft vertically at rest and stout wing tip skids were necessary. In land-plane form, with large inversely tapered ailerons replacing the constant chord units, the Avro 501 was so quaint a structure that it soon earned the name ‘Rickety Ann’. After delivery to Eastchurch it had to be lightened and several airscrews tried before F. P. Raynham could complete the acceptance tests. Bearing naval serial 16 it was flown to Shoreham on June 2, 1913, by Raynham with Lt Seddon as passenger.
  The first RNAS Avro 503 seaplane, 51, was delivered in crates to the Isle of Grain on September 8, 1913. It easily passed its RNAS trials there on September 25, 1913, when, piloted by F. P. Raynham, it reached a speed of 64 mph and climbed to 3,000 ft in 19 minutes with full tanks (36 gallons of petrol and 10 gallons of oil giving 4 hours’ endurance) while carrying a passenger and wireless equipment. The second machine, 52, was delivered to the Isle of Grain on October 7, 1913, and the third, 53, on October 15, 1913. This last machine incorporated some undefined improvements. All three machines were later converted to landplanes and were in use at Eastchurch in September 1914. No. 52 remained active until January 1916.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company (reconstituted as A. V. Roe, and Co. Ltd. 11.1.13), Brownsfield Mills, Great Ancoats Street, Manchester (moved to Clifton Street, Miles Platting, Manchester 4.13); and Shoreham Aerodrome, Sussex
   Power Plant: One 100 h.p. Gnome
   Dimensions, Weights and Performances:
   Avro 503 seaplane
   Span (upper) 50ft. 6 in.
   Span (lower) 47ft. 0 in.
   Length 33ft. 6 in.
   Height 12ft. 9 in.
   Wing area 567 sq. ft.
   All-up weight 2,200 lb.
   Maximum speed 50 m.p.h.
   Initial climb 225 ft./min

   Production:
   Avro 503 prototype first flown at Shoreham 28.5.13, to the German Navy 6.13 with serial D12
   Three Avro 503 seaplanes with serials 51, 52 and 53 built for the RNAS and delivered to the Isle of Grain. All later converted to landplanes before September 1914. 51 crashed at Chingford 11.8.15, 52 withdrawn from use 1.16, 53 withdrawn from use at Eastchurch 11.15

Avro 504 to Avro 504H

  Design work on a successor to the Avro 500, begun at Brownsfield Mills in November 1912, was completed at the new Clifton Street works early the following year, Messrs Chadwick and Taylor being responsible for the fuselage and undercarriage and H. E. Broadsmith the wings. Designated Avro 504, it was very lightly constructed with a rectangular section, wire braced, box-girder fuselage built from four ash longerons channelled for lightness and strengthened by flanges. Cross struts were of spruce. For maximum view the pilot sat in the rear, the passenger occupying the front cockpit, from the corners of which four ash struts supported the centre section. Equal span, two bay wings were rigged with 2 ft stagger and braced by streamline section, hollow spruce interplane struts pin-jointed to the spars. Each wing panel consisted of five main ribs with spanwise stringers supporting a number of contour-forming strips of wood anchored to leading and trailing edges. Lateral control was by inversely tapered ailerons rigidly fixed at the inner end, the widened outer ends of which were warped by means of cables.
  Although similar to that of the Avro 500, the undercarriage was a much improved and simplified unit. An ash skid was anchored to the fuselage by steel V struts as before, but the axle was no longer bolted to it and was no longer a laminated spring. Instead, a simple steel tube axle was used in conjunction with two main undercarriage legs having built-in rubber shock absorbers (8 ft 8 in of bungee cord wound round the two halves of the leg) in streamlined cases. The tail skid was attached to the bottom of a comma-type rudder.
  In design, construction and performance the Avro 504 was considerably in advance of other 1913 types and benefited from the use of an improved wing section. Power was supplied by one of the new 80 hp Gnome rotaries (the actual power output of which is said to have been nearer 62 hp) installed in a square section cowling bulged on top and sides.
  To give it the widest possible publicity the Avro 504 was entered for the 1913 Aerial Derby and consequently was built in considerable secrecy. Its arrival at Hendon on September 20, 1913, morning of the race, was therefore something of a sensation as it was obviously very fast and the impression of speed was heightened by its staggered mainplanes. When F. P. Raynham crossed the finishing line in fourth place at an average speed of 66-5 mph, few realised that the Avro 504 was virtually untried, having been delivered at Brooklands only three days before (September 17), and flown for the first time on the following day.
  After the Aerial Derby the Blackburn Aeroplane and Motor Co Ltd issued a challenge to its Lancashire rivals and on September 29 Raynham flew the Avro 504 from Brooklands to Leeds for a race against a new Blackburn monoplane flown by Harold Blackburn. The 100 mile race was held on October 2 over a course starting and finishing at Leeds and passing over York, Doncaster, Sheffield and Barnsley. With H. V. Roe as passenger, Raynham flew neck and neck with Blackburn until bad visibility forced him to land near Barnsley.
  Although basically a sound aeroplane the 504 needed modification and went back to the Manchester works where the engine mounting was changed for an improved version carrying more streamlined cowlings. Aileron control was also lightened by replacing the warping arrangement with constant chord hinged ailerons with wires to complete the circuit in place of the original rods. The wing structure was strengthened by replacing the hollow pin-jointed interplane struts by solid ones fitted in metal sockets. Redelivered at Brooklands at the end of October, the 504 was flown a great deal by Raynham during the following month. He made a forced landing at Horley with a broken carburettor control during the Hendon-Brighton-Hendon race on November 8; flew from Brooklands to Farnborough and back on November 15; gained second place in the Shell Trophy Race at Hendon the same afternoon and broke the lap record at 73 mph; spent a week on day and night flying at Shoreham and flew to Farnborough for official tests on November 24. With a passenger and fuel for three hours the Avro 504 clocked 80-9 mph over the measured mile and climbed to 1,000 ft in 1 min 45 sec.
  An outstanding performance put up by Raynham on February 4 was a climb to 15,000 ft over Brooklands. This exceeded the existing British altitude record by almost 2,000 ft but was not an officially observed record. During the descent Raynham shut off his engine, put the machine into a glide, and 25 minutes later was at 5,000 ft over Hendon some 20 miles away. He then spiralled down to a landing, still without using his engine. Carrying R. J. MacGeagh Hurst in the front seat Raynham made an officially observed climb to a record height of 14,420 ft over Brooklands on February 10.
  Later in the season the machine was purchased by the Daily Mail and toured the country giving passenger flights piloted by F. P. Raynham and G. Lusted. A. V. Roe and Co built an interchangeable twin float undercarriage so that the machine could be flown off the sea at coast resorts. At the same time the original 80 hp Gnome was replaced by an 80 hp Gnome Monosoupape which was supposed to give more power but which in fact gave only trouble. First flights as a seaplane took place at Paignton in April 1914, after which it visited Falmouth, Southport and Ireland, but when war was declared on August 4 the machine was at Shoreham where it was immediately commandeered. Two days later the career of this historic aeroplane ended when the engine failed as Raynham took off to deliver it to the RNAS. With no height in hand there was no alternative to putting the machine down on land where it was damaged beyond repair.
  Series production of the Avro 504 began in the summer of 1913 when the War Office placed a contract for twelve machines. This brought about some restressing of the wings to comply with their strength requirements which included doubling the depth and width of the rear spar. Others were built for non-military and experimental purposes, one of which was exhibited at Belle Vue, Manchester, on January 1-3, 1914, and another, delivered at Brooklands on February 16, was fitted with the first Armstrong Whitworth-built 100 hp A.B.C. engine. After endless engine runs Raynham made what was possibly its only flight with this engine early in April. Drawings were also prepared for the installation of a 65 hp Austro-Daimler engine but as far as is known this scheme was shelved. A third Avro 504 was exhibited with rubber-sprung float undercarriage at the Olympia Aero Show in March 1914 and another was delivered to Harold Blackburn at Southport in July. In common with thousands of Avro 504 variants built in later years, these aircraft were noticeably different from the prototype because the top longerons sloped downwards aft of the cockpits to make the fuselage symmetrical in side elevation.
  Two Avro 504s, almost the last of the twelve War Office machines, were delivered at Brooklands on June 5, 1914, and it was in one of these on June 12 that F. P. Raynham succeeded in looping a 504 for the first time. They were delivered next day to Farnborough where 376 (the first machine of the batch) was tested to destruction during July. A few Avro 504s were among the aircraft of No.5 Squadron RFC when it left for France on August 13, one of which became the first British aeroplane brought down by the Germans when Lts V. Waterfall and C. G. G. Bayly were hit by infantry fire in Belgium on August 22. In mid-October, 383, another Avro of the squadron was fitted with a Lewis gun by 2nd-Lt L. A. Strange whose gunner, Capt L. da C. Penn-Gaskell, strafed a troop train at Perenchies and forced down an Albatros two-seater near Neuve-Eglise a month later. Only a few Avro 504s saw front-line service and the greatest number in RFC squadrons in France at any one time was thirteen.
  The Admiralty placed an order in the spring of 1914 for one Avro 504 and for six others a few months later. The first of these was delivered to the RNAS Eastchurch Squadron on November 27, 1914. Armed with four 16 lb bombs and piloted by Flt Sub-Lt R. H. Collet, an attempt to bomb the Bruges submarine depot on December 14 was foiled by bad visibility and an attack was made on the Ostend-Bruges railway instead. Very few offensive sorties were made by the Avro 504, the most ambitious being the brilliant and historic raid on the Zeppelin sheds at Friedrichshafen. A special flight of four machines formed at Manchester in October 1914 by Sqn Cdr P. Shepherd, was equipped to carry four 20 lb bombs per aircraft and shipped from Southampton to Le Havre. They arrived at Belfort by train on the night of November 13, 1914, and were hidden in a barn for fear of arousing the suspicions of local spies. It was not possible to flight test them and the first machine, 874, took off untried at 9.30 a.m. on November 21 piloted by Sqn Cdr E. Featherstone Briggs. Flt Cdr J. T. Babington then left in 875 followed by Flt Lt S. V. Sippe with five minutes separation in 873. Flt Sub-Lt R. P. Cannon’s machine 179 (the first Avro 504 built for the RNAS) broke its tail skid and could not go. The raiders followed the Rhine at 5,000 ft, crossed Lake Constance at 10 ft and put several bombs into the airship sheds from 1,200 ft. They narrowly missed destroying naval Zeppelin L.7 but hit the gas plant which exploded with considerable violence. Briggs was shot down but the others made the 125 mile return trip in safety after four hours in the air. Flown by Flt Lt H. L. Rosher, Sippe’s Avro 873 was one of five belonging to No.I Sqn RNAS which twice bombed Ostend and on March 24, 1915, destroyed two U-boats in an attack on the submarine depot near Antwerp. Together with 179 and 875, it survived to return to England for overhaul and transfer to school work. A pioneer Zeppelin interception was also made by an Avro 504 from RNAS Westgate piloted by Flt Sub-Lt Mulock who made contact with LZ.38 in the early hours of May 17, 1915. The airship climbed too rapidly for him to use his armament of two hand grenades and two incendiary bombs but later the same night the Avro 504 1009, piloted by Flt Cdr A. W. Bigsworth, pursued LZ.39 towards Ostend with more success. He managed to gain sufficient height to drop four 20 lb bombs on the airship’s stern and caused slight damage by fire which led to a heavy landing at Evere, Brussels.
  When the Avro 504 was relegated to training, a duty it was destined to fulfil with distinction for over 15 years, A. V. Roe and Co designed and supplied a self contained dual control unit comprising seats, control columns and rudder bars. Later in 1915 converted machines were joined by a number specifically built as trainers, total Avro 504 production amounting to at least 88 aircraft. As the war progressed, modification gave rise to a series of variants. The Avro 504A, built for the RFC, was a strengthened version with wide-chord interplane struts and ailerons of reduced span. The lower wing roots were sometimes stripped of fabric to improve the downward view and 2905, delivered on January 17, 1916, was used at Farnborough for fabric tests. At least B3103 was fitted with an improved undercarriage having rear shock legs and front radius rods for use by the CFS Communications Flight at Lopscombe Corner, Salisbury, in 1918.
  The Admiralty insisted on wing spars of greater cross section and was supplied with a drastically modified version known as the Avro 504B. It reverted to long-span ailerons and was identified by a large, unbalanced rudder hinged to a considerable dorsal fin. The top longerons were recessed to provide curved cut-outs in the sides of the rear cockpit. A stout ash tail skid, sprung with rubber cord and hinged to a pylon under the rear fuselage, became standard fitment on this and all subsequent 504 variants. A few RNAS Avro 504Bs were used operationally at Dunkirk, including 9890 and N5267 which had forward-firing guns and interrupter gear.
  The majority of Avro 504Bs were naval trainers and late production models had the 80 hp Le Rhone, provision for Scarff ring and no cut-outs to the rear cockpit. At least one was used in early deck landing arrester gear experiments. In the coastal reconnaissance role the endurance was increased to 4 1/2 hours but this soon proved insufficient and 80 examples of a singleseat version having 8 hours endurance were built. Powered by an 80 hp Gnome and known as the Avro 504C, it had a large cylindrical fuel tank in place of the front cockpit and a gap in the top centre section through which a Lewis gun could fire incendiary ammunition upward at an angle of 45 degrees. The RFC equivalent, conceived in 1915 under the designation Avro 504D, retained the balanced comma-type rudder and short-span ailerons, but had the recessed longerons and wing root modifications of the Avro 504C. Only six 504Ds were built and delivery began in August 1915.
  Modification on this scale led to a severe weight penalty and additional power had become a dire necessity. The next RNAS variant, the Avro 504E, was therefore fitted with the 100 hp Gnome Monosoupape. At the same time the rear cockpit was moved farther aft and the change of C.G. position caused by installing the main fuel tank between the cockpits was counteracted by reducing the stagger from 24 to 9 in. Centre section struts were then repositioned to converge towards the top in side elevation. The 504E also reverted to the straight top longerons of the prototype but was fitted with the fin, rudder and ailerons of the 504B. Ten were built, some of which were used at Chingford and Fairlop and one at Cranwell.
  Designation Avro 504F was given to a single Avro 504C, 8603, fitted at the suggestion of the Admiralty with a 75 hp Rolls-Royce Hawk six-cylinder in-line engine. It was evidently an unsuccessful union as a contract for 30 Avro 504F aircraft was cancelled and replaced by one for the 80 hp Gnome version.
  Designation Avro 504G was used by the RNAS for the 80 hp Gnome-powered Avro 504B conversions having racks for practice bombs, synchronised front Vickers guns and a Scarff ring for a Lewis gun on the rear cockpit.
  Last of the early exploratory variants was the 504H, a strengthened 504C fitted under the supervision of Sqn Cdr E. H. Dunning in 1917 with catapult pick-up points and a special padded seat. Piloted by Flt Cdr R. E. Penny this machine later became one of the first aircraft successfully launched by catapult.
  At this stage of the war orders for the several variants were far in excess of production capacity at Manchester and a number of sub-contractors were brought in as listed in the data section.


SPECIFICATION AND DATA
   Manufacturers:
   A. V. Roc and Co. Ltd., Clifton Street, Miles Platting, Manchester
   The Bleriot & Spad Aircraft Works, Addlestone, Surrey
   The Brush Electrical Engineering Co. Ltd., Loughborough
   The Eastbourne Aviation Co. Ltd., Eastbourne
   The Humber Motor Co. Ltd., Coventry
   Parnall and Sons, Mivart Street, Eastville, Bristol
   The Regent Carriage Co. Ltd., Fulham, London
   S. E. Saunders Ltd., East Cowes, Isle of Wight
   The Sunbeam Motor Car Co. Ltd., Wolverhampton
   Power Plants:
   (Prototype)
   80 h.p. Gnome
   80 h.p. Gnome Monosoupape
   (Avro 504 and 504A)
   80 h.p. Gnome
   80 h.p. Le Rhone
   100 h.p. A.B.C.
   (Avro 504B)
   80 h.p. Gnome
   80 h.p. Le Rhone
   (Avro 504C and 504D) 80 h.p. Gnome
   (Avro 504E) 100 h.p. Gnome Monosoupape
   (Avro 504F) 75 h.p. Rolls-Royce Hawk
   (Avro 504G and 504H) 80 h.p. Gnome
   Dimensions:
   Span 36 ft. 0 in. Length 29 ft. 5 in.
   Height 10 ft. 5 in. Wing area 330 sq. ft.
   Weights and Performances:
   Prototype Avro 504 landplane seaplane Avro 504A Le Rhone
Tare weight - 924 lb. 1,070 lb. 1,050 lb.
All-up weight 1,550 lb. 1,574 lb. 1,719 lb. 1,700 lb
Maximum speed 81 m.p.h. 82 m.p.h. 75 m.p.h. 86 m.p.h.
Climb to 3,500 ft. 7 min.* - - 7 min.**
Endurance 3 hours - - 4 1/2 hours***
*With 80 h.p. Gnome Monosoupape.
**With 80 h.p. Gnome 9 min. 30 sec.
***With Avro 504C and 504D 8 hours.


Avro 504J and Avro 504K

  In the autumn of 1916 a more powerful version of the Avro 504A with the 100 hp Gnome Monosoupape was produced for the RFC. This variant, designated 504J and known in the RFC as the ‘Mono Avro’, was externally identical with the earlier type and large numbers ordered as 504As were completed as 504Js.
  Among the first recipients of the Avro 504J was the School of Special Flying founded at Gosport in July 1917 by Maj R. R. Smith-Barry. Here (and later at similar schools at Shoreham, Lilbourne, Redcar, Ayr and Curragh) instructors were introduced to Smith-Barry’s revolutionary flying training technique, a system based on demonstration and explanation by an instructor who was in verbal communication with the pupil. The ‘Gosport’ speaking tubes specially designed for this purpose were still to be found in club aircraft half a century later. The Avro 504J was fully aerobatic and made an ideal training aircraft because its light and powerful controls quickly showed up faults in a pupil’s flying. It is now historically important as the aeroplane which made possible a system of training which, in modified form, became part of the RAF’s Flying Training School syllabus for more than 40 years. As the standard RFC trainer, the Avro 504J was ordered in such quantity that contracts were placed with additional sub-contractors. Components for Avro-built machines were constructed in Manchester for erection at the company’s new aerodrome at Hamble.
  In his memoirs C. A. Nepean Bishop recalls that the Gosport School Avro 504J C4448 was the personal machine of Capt Williams whose favourite trick was to land between the hangars, touch down on the tarmac, swing completely round and finish the landing run inside ‘C’ Flight hangar. Among other Gosport instructors were Maj E. L. Foot who was to become well known as airline, test and sporting pilot in the years immediately after the War, and Capt Duncan Davis, manager of Avro’s South Coast joyriding aircraft in 1919-20 and CFI of the Brooklands School of Flying in the 1930s. A distinguished pupil was HRH Prince Albert (later King George VI) who learned to fly on C4451. In 1918 a team of instructors took four Mono Avros across the Channel to demonstrate the Gosport system to the French.
  By the end of 1917 the 100 hp Gnome Monosoupape was outmoded as a front line powerplant and British production of this engine was allowed to tail off. To prevent interruption of Avro 504J production through engine shortage, all surplus rotaries, including 80 hp and 110 hp Le Rhones as well as 130 hp Clergets, were collected from English and French aerodromes. There was no difficulty in fitting the 80 hp Le Rhone and a number of 504Js were thus powered, but it was necessary to modify the front fuselage before larger engines could be installed. Following the trial installation of a 130 hp Clerget in B3157 for Smith-Barry at Gosport at the end of 1917, the Technical Dept of the Air Board asked A. V. Roe and Co to produce adaptors and a new type of universal engine mounting. In the older machines this was of the two bearer type, the front bearer being in the form of a ball race supported on four tubular arms forming extensions to the fuselage longerons. This ‘spider’ was now replaced by an overhung mounting designed by H. E. Broadsmith which consisted of two bearer plates which would accept any suitable engine and allow the use of a smooth open fronted cowling. Irrespective of the type of engine fitted, aircraft built with this mounting were known as the Avro 504K, even though many had been ordered as 504Js or even 504As as shown in the table on page 61. The original ‘Clerget Avro’ B3157 joined ‘F’ Flight, School of Special Flying, and crashed at Gosport on March 2, 1918.
  With standardisation accomplished the way was clear for greatly increased production and the Avro company was authorised to plan the construction of 100 machines a week, plus spares. They were also required to produce 20 sets of knock down parts per week for assembly at the Eastern Aircraft Factory at Aboukir, Egypt and by the Armistice production had reached eighty Avro 504Ks a week, including twenty sets of components for Aboukir.
  As a result of demonstration flights over Washington by Avro 504J C4312 imported by the British Mission under Col Lee in the winter of 1917-18, fifty-two Le Rhone engined 504Ks were purchased by the Americans in July 1918. These were used by the AEF for advanced training at No.3 Instruction Centre, Issoudun, France, and after the War survivors were shipped to the USA, where one or two still exist.
  Major modification of the Avro 504J was confined to the fitting of shortspan, single-bay wings and curved fin to B4264 at Gosport in January 1918. Standard 36 ft mainplanes were eventually replaced, rigged experimentally with the gap reduced from 5 ft 6 in to 5 ft 1 1/4in. In March 1918 the same set of short-span wings was fitted temporarily to B3155, a two-seater with shortened fuselage and armed with a Lewis gun. In the following May it flew as a single-seater with the fuel tank in the front cockpit, and this led logically to the first of a number of 110 hp Le Rhone engined single-seat 504Ks for high altitude work with Home Defence Squadrons in the north of England. These had the gravity tank repositioned to port to make way for a Lewis gun on the top centre section, and with front cockpit faired in could reach 18,000 ft. Some were fitted later with a low drag V-type undercarriage similar to that of the Avro 521. Two so modified were flown at Gosport - C605 with 130 hp Clerget on June 15, 1918 and C604 with Le Rhone on February 3, 1919.
  Total wartime production of Avro 504s of all marks exceeded that of any other type of British aeroplane but the oft quoted figure of 8,340 aircraft (3,696 by A. V. Roe and 4,644 by sub-contractors) is obviously in excess of the actual total. Nine were delivered to the Expeditionary Force in France in 1914; 4,771 to training units; 274 to Home Defence Units; 392 to the Middle East Brigade and 52 to the Americans. When the RFC and RNAS came under unified command on April 1, 1918, Avro 504Js and Ks were in use with almost every Service unit in Britain so that on October 31, 1918, there were 2,999 on RAF charge (including 2,267 at flying schools and 226 on Home Defence). One hundred and eleven were in Egypt and Palestine, where some were pressed into emergency air mail service during the Egyptian rising of March-April 1919.
  In 1919 the Sunbeam Motor Co, sub-contractor for the Avro 504B, J and K, fitted one of its 100 hp water-cooled Dyak airship engines into a 504K airframe. With brass nose radiator and attendant plumbing it was a heavy powerplant which substantially reduced payload. Conversions were consequently few but two were supplied to Norway in 1920 and several were built for civil use with the Dyak engine in Australia in 1922.
  The Royal Aircraft Establishment found the 504K a most useful test vehicle in the years immediately after the war, and each of Farnborough’s resident machines was used for a wide variety of experimental flying. One important phase was flight testing a number of wings designed by Boulton and Paul, Humber, Vickers and the Steel Wing Company with metal spars and/or ribs. The metal wing programme was initiated partly through timber shortage but chiefly because seemingly identical wooden spars varied considerably in strength and weight. Minor experimental devices flown on the 504Ks ranged from a Leitner-Watts metal airscrew to a windmill-driven clear vision rotating windscreen.
  A postwar gunnery trainer version of the Avro 504K (130 hp Clerget) was designated Avro 540 but differed from standard only in the region of the rear cockpit which was strengthened and built up to take a Scarff mounting for a rear gunner. There was no new production, the few that existed being converted 504Ks.
  Of greater importance was the 504K’s contribution to low speed flying research in the course of which H2402 was fitted with a V-type undercarriage, water ballast tanks near the C.G. and in the tail, as well as an immense fin and unbalanced rudder. Eleven gallons of water could be pumped into the rear tank in the air to enable the aircraft to fly at very large angles of incidence (up to 35 degrees) with the object of exploring controllability in stalled flight and so reduce the risk of hitting the ground in a nose-down attitude as described in R. & M. 991. In the event, H2402 experienced almost uncontrollable longitudinal oscillations and a second machine, F8940, with similar undercarriage, fin and rudder, was flown with variable-incidence tailplane and lead weights up to 80 lb over the tail skid. Large range differential ailerons allowing upward angles in excess of 90 degrees and interconnected with leading-edge slots, were actuated by a wheel mounted on the control column. Research also embraced balanced ailerons mounted at mid-gap and concluded with flight tests by E3269 equipped with Handley Page slots inter-connected with Frise-type balanced ailerons. This aircraft was demonstrated sensationally by F/Lt P. W. S. Bulman at Farnborough on April 15, 1925. A list of the main experimental machines appears in the data section.
  The 504Js were declared obsolete in September 1921 but the 504K remained in service as the standard RAF trainer with the CFS and Nos.1, 2, 3, 4 and 5 Flying Training Schools until the late 1920s. It also served with No. 24 (Communications) Squadron; with Nos.600, 601, 602 and 603 Auxiliary Air Force Squadrons; and with Fleet Air Arm training units at Netheravon and Leuchars. It took part in Hendon RAF Displays, beginning in 1920 when F/O Quinland cavorted ‘L’Avro Comique’ B3292 with extra large four-speed and reverse gear-box, be-cobwebbed undercarriage, vacuum cleaner, anchor, kettle, flue pipe, jazz painted interplane struts and four dummy heads! The Display of July 3, 1921 included a standard Avro race won for Kenley by F/O P. Murgatroyd who won again in the following year while representing Cranwell. Crazy flying by F/Lt Jack Noakes in 1921 and F/Lt W. H. Longton in 1922 brought congratulations from King George V. The Avro 504K made its final appearance in a star role in 1923 as the ‘Orva Mayfly’, which paraded in front of the crowd with ‘A.B.C. Lion’ engine, wireless clothes line, kettle, chimney, six-inch gun and carrot accelerator!
  The last Avro 504Ks, built by A. V. Roe to Contract 707157/26, appeared in two batches. The first 40, delivery of which was completed on November 11, 1926, were followed by 10 delivered by January 17, 1927.
  In 1990 three Avro 504Ks survived in the United Kingdom in military markings, D7560, fitted with the wings of E3104, property of the Science Museum, London, was on permanent exhibition. The Royal Aeronautical Society’s G-ABAA painted as H2311 was undergoing restoration for display at the Greater Manchester Museum of Science and Industry and the Shuttleworth Collection’s H5199, which had previously carried the fictitious marks E3404, was airworthy at Old Warden.
  G-ABAA which was flown from Scotland by F/Lt Birch to join the Nash Collection at Brooklands in 1938 was overhauled by A. V. Roe and Co for the Royal Aeronautical Society in 1950 and flown at the Farnborough RAF display by Gp Capt L. S. Snaith in July of that year. After a period in store at Hendon and London Airport, it was transferred to Upavon in 1962 and was later held in store at Henlow before being transferred to Manchester. The Shuttleworth machine, c/n R3/LE/61400, which had been stored for many years at Old Warden was rebuilt by apprentices at the Chadderton works of A. V. Roe and flew again in 1955. It later took part in the film Reach for the Sky.


SPECIFICATION AND DATA
   Manufacturers:
   A. V. Roe and Co Ltd, Park Works, Newton Heath, Manchester; and Hamble Aerodrome, near Southampton, Hants.
   Australian Aircraft and Engineering Co Ltd, Sydney, NSW, Australia
   The Brush Electrical Engineering Co Ltd, Loughborough
   Canadian Aeroplanes Ltd, Toronto, Canada
   The Eastbourne Aviation Co Ltd, Eastbourne
   The Grahame-White Aviation Co Ltd, Hendon Aerodrome, London, N.W.9
   Harland and Wolff Ltd, Belfast
   The Henderson Scottish Aviation Factory, Aberdeen
   Hewlett and Blondeau Ltd, Oak Road, Leagrave, Luton, Beds.
   The Humber Motor Co Ltd, Coventry
   Morgan and Co, Leighton Buzzard, Beds.
   Nakajima Hikoki Seisaku Sho, Ohta-Machi, Tokyo, Japan
   Parnall and Sons, Mivart Street, Eastville, Bristol
   Frederick Sage and Co Ltd, Peterborough and London
   S. E. Saunders Ltd, East Cowes, Isle of Wight
   Savages Ltd, King’s Lynn, Norfolk
   Societe Anonyme Beige de Constructions Aeronautiques, Haren, Brussels, Belgium
   The Sunbeam Motor Car Co Ltd, Wolverhampton
   Yokosuka Naval Arsenal, Japan

Powerplants:
   (Avro 504J)
   One 80 hp Le Rhone
   One 100 hp Gnome Monosoupape
   (Avro 504K)
   One 90 hp RAF.1A
   One 100 hp Gnome Monosoupape
   One 90 hp Thulin
   One 100 hp Curtiss K.6
   One 100 hp Sunbeam Dyak
   One 110 hp Le Rhone
   One 130 hp Clerget
   One 150 hp Bentley B.R.l
   One 170 hp A.B.C. Wasp I
   One 220 hp Hispano-Suiza

Dimensions:
   Span 36 ft 0 in
   Length (rotary engines) 29 ft 5 in (Dyak) 28 ft 11 in
   Height 10 ft 5 in
   Wing area 330 sq ft

Weights and Performances (Avro 504K):
100 hp Gnome Monosoupape 110 hp Le Rhone 100 hp Dyak
Tare weight 1,100 lb 1,231 lb 1,320 lb
All-up weight 1,800 lb 1,829 lb 1,857 lb**
Maximum speed 82 mph* 95 mph 70 mph
Cruising speed - 75 mph -
Climb to 8,000 ft - 6-5 min -
Service ceiling 13,000 ft 16,000 ft -
Endurance 3 hours 3 hours 2 3/4 hours
Range - 250 miles
*At 6,500 ft
**2,400 lb with 220 hp Hispano-Suiza.

Experimental Avro 504Ks used at the RAE, Farnborough:
   D8837 Used for static strength tests prior to 3.19
   D9068 The ‘fireproof’ Avro, fitted with 170 hp A.B.C. Wasp and flown 19.2.20 to 3.6.20 when crankshaft failed. Flown again 28.9.22.
   E3269 CTE petrol control valve tests 9.18; metal (including Vickers) wing tests 4.7.19 to 1.6.20; turn indicator tests 5.20; plug, fuel, temperature and Tampier Needle/Bloctube carburettor tests by C Flight up to 6.22; further steel wing tests 8.22; lateral control at low speeds until 2.5.25
   E3621 Steel spar tests commenced 20.5.19, destroyed 14.7.19 in fatal air collision over Farnborough with S.E.5A D7014
   F2234 Stall indicator, Holt flare, navigation light and Adamchick undercarriage tests 11.6.23 to 24.4.25
   F8857 Parachute tests 2.7.19 to 3.11.19; turn indicator tests 13.1.20; accident taking off from Laffan’s Plain 16.1.20
   F8940 Steel wing and accelerometer tests 28.7.21 to 11.21; low speed lateral control tests up to 8.22; F/O Bouchier flew it in landing contest, Hendon 29.6.22; automatic control recorder tests from 11.8.22; airscrew tests 4.23
   H2202 From Martlesham 28.7.22 for Tampier needle/Bloctube carburettor tests by Engine Research Flt, left for Kenley 18.12.22
   H2214 Leitner-Watts steel airscrew tests, commencing with ground runs 20. 9.21; lateral control tests 8.22; automatic control recorder tests 15.9.22 to 20.6.23; lateral control movement recorder tests from 26.6.24
   H2365 To Wireless and Photographic Fit 17.6.24 for short wave telephony and night flying equipment trials to at least 7.2.25
   H2402 Steel wing tests 22.1.19 to 1.3.20; revolving clear view windscreen tests 10.11.20 to 1.12.20; instrument, control column force recording, accelerometer, low speed lateral control, fuel pump, Mk.IV sextant and clinometer tests by A Flight up to 8.22; undercarriage collapsed
18.3.25
   J7555 Two Avro 504Ks A 101 and A 102, equipped with Sperry Mark A and gyroscopes and radio control gear, were acquired 8.24 from the Sperry
   J7556 Gyroscope Co, New York. To the RAE Instrument Flt 1.11.24 for research into automatically controlled flight. The aircraft were re-serialed J7555 and J7556 though only the latter was used; flown on six occasions 3.25 to 12.26.


Avro 504K (civil)

  The vast armada of Avro 504Ks rendered surplus by the 1918 Armistice included not only wartime training veterans but also large batches of new machines at storage units or still in the factories. An offer by A. V. Roe and Co to repurchase them en bloc was refused on the grounds that the Disposal Board found it impossible to compute the precise number of saleable aircraft. Sales therefore began by public auction at No.1 Aircraft Salvage Depot, Hendon, but in 1920 Handley Page Ltd bought all Disposal Board stocks and the 504Ks were thereafter marketed by its subsidiary, the Aircraft Disposal Co Ltd of Croydon. Trade was brisk despite the late G. P. Olley’s forced landing on March 31, 1920, in Southwark Park pond in the company’s demonstrator G-EAHW (130 hp Clerget). Foreign and Commonwealth governments made considerable inroads into stocks but even greater numbers were sold for civilian use. Low first cost and a seemingly endless spares backing, made the Avro 504K the only military aircraft of the period to find lasting favour as a civil type. Between 1919 and 1930 over 300 were allotted civil registrations in Britain alone and before the advent of the D.H. Moth in 1926 the Avro 504K was the most common British aeroplane. The majority had the dual controls removed and the decking cut away to make room for a third seat but a few were used for flying instruction and the total included a number ferried abroad in temporary civil marks.
  Civil flying was sanctioned in Britain at Easter 1919, a memorable Bank Holiday when A. V. Roe’s immortal trainer embarked on an even greater career as a pleasure trip machine. Its usefulness extended over two decades and its name will be linked for ever with the halcyon days of itinerant joyriding, the story of which falls into four clearly defined periods.
  Excited by the deeds of great wartime pilots, the public developed a thirst for flying which earned every airworthy 504K a handsome living for the rest of 1919. Despite an ambitious essay into organised pleasure flying by the Avro company, lesser concerns also made a great deal of money, particularly in Scotland. Quick to fill the gap when Avro withdrew from the business in 1920, many former RAF pilots bought 504Ks in the hope of reaping similar rewards but over 50 such mushroom enterprises were ended within the year by the trade slump. The third period, which lasted until the end of the decade, saw Avro pleasure flight business reduced to a number of old established firms run by a handful of seasoned pilots whose lives were dedicated to the game. Their eventual absorption into the great air displays of the 1930s brought the career of the 504K to an end as it had begun, in organised joy flying on the grand scale.

Genesis
  A. V. Roe and Co started operations at Hamble at Easter 1919 with three Avro 504Ks (100 hp Gnome Monosoupape) in military marks. Piloted by G. L. P. Henderson, H. A. Hamersley, F. Warren Merriam and others, they carried 359 passengers at £1 a head on the first day! Some 3 1/2 weeks later the Avro Transport Company was set up to run a daily return service between Alexandra Park, Manchester and Blackpool Sands via Southport. The inaugural flight, made on May 24 by four 3-seat 504Ks (110 hp Le Rhone), carried Avro director John Lord and a selection of civic dignitaries. During the 18 1/2 week life of the service, bad weather only prevented 28 of the 222 scheduled flights and when the route closed for the winter (and for ever) on September 30, 8,730 miles had been flown without a forced landing.
  Inspired by results at Hamble, the Avro Transport Company launched a nation-wide joyriding programme and put G. L. P. Henderson in charge. As prelude to this assignment he flew a brand new 504K (110 hp Le Rhone) H2586/G-EAEV into 6th place in the Aerial Derby at Hendon on June 21, 1919, at an average speed of 75-22 mph. Leading pilots of the day whom he had appointed to take charge of ‘Southern Area’ operations were already hard at it at Hounslow Heath (Maj A. G. Taylor); Manston (Capt Duncan Davis); Southsea/Eastney (F/Lt E. A. Sullock); Weston-super-Mare sands (Capt D. G. Westgarth-Heslam); Brighton/Patcham/Blatchington Farm (Capt D. I. M. Kennard); Swansea/Brynmill (F. G. M. Sparks); and Porthcawl (Capt E. D. C. Herne). The ‘Northern Stations’ were Blackpool South Shore (Capt W. G. R. Hinchliffe); Southport/Birkdale Sands (Capt Collison); Fleetwood/Scale Hall and Morecambe Sands (Lt Macrae); Rhyl (Capt E. Maitland Heriot); Liverpool/Waterloo Sands (machines diverted from the Manchester-Blackpool service on Wednesdays and Saturdays); Man Chester/Alexandra Park (Lt-Col G. L. P. Henderson); and Isle of Man/Douglas Promenade/Ramsay (Lt G. B. Moxon). Avro 504L seaplanes and Avro 536 five seaters were also used as detailed in their own chapters.
  During Wakes Weeks, industrial workers, coal miners and the like spent lavishly on longer flights, looping and inverted flying and by August 1 over 10,000 passengers had been carried at Blackpool alone. Similar figures were returned at Southport where flying often continued by moonlight and one woman passenger had 15 stunt flights within a week. In mid-August a gale of unprecedented fury struck the coast, wrought havoc among Avros pegged down with sandbags on the beaches and reduced the number in service on August 31 to 17.
  At Hounslow Heath where 6,400 passengers were carried during the season, Avro 504K E3289/G-EAAM and Avro 536 K-105/G-EAAP were chartered by the Evening Standard in July for daily newspaper flights to Brighton and Southsea. Another made an incredible eight hour flight from Perth to Hounslow on August 12 with 60 brace of grouse.
  Let by G-EAIH, ’II and ’IJ which left the Manchester works on July 28, 1919, nine Avros (including G-EAJQ, 'JU, a 536 and two 504Ls) attended the First Air Traffic Exhibition at Amsterdam in August 1919. A sustained demand for joy flights kept them in the Netherlands and the last two did not arrive back at Lympne until January 3, 1920. Meanwhile a rail strike in Britain had brought almost the entire fleet to Hounslow to convey passengers, newspapers, films and light freight to the provinces. The return flights were offered as a daily service to London and once again demand was far in excess of available seats. When petrol restrictions brought the season to an end the Avro Transport Company had carried over 30,000 people and flown the equivalent of 12 1/2 circuits of the earth. The craze for flying bordered on hysteria. Garden parties without a 504K were considered unfashionable and the Swansea machine was frequently ‘detached’ to the Abernant Hotel, Llanwrtyd Wells, for this purpose, and when the Town Crier flew over Swansea ringing his bell in flight, the local police could hardly control the resultant crowd of would-be aviators.
  Hounslow was not the only 504K pitch in the London area. Prewar premises were reopened at Hendon by the Grahame-White Aviation Co Ltd as the London Flying Club, a centre of fashionable society equipped with 12 Avro 504Ks acquired from the nearby Salvage Depot. Painted in carroty pink, they carried enlarged versions of their RAF serials until full civil markings on white rectangles were applied some months later. Instruction was available and an attempt was made to revive Saturday afternoon pylon racing but the Avros were engaged mainly on joy flights, 5,100 tickets being sold in the public enclosures that season. They also carried the Daily Mirror to the Midlands during the railway strike but the concern degenerated into a country club and flying ceased at the end of 1920. Across the road at Stag Lane, the London and Provincial Aviation Co Ltd used a single machine, G-EABT, which was later flown at Yarmouth by T. Neville Stack and George Lusted. An eight-strong fleet (110 hp Le Rhone engines), flown at Northolt by the Central Aircraft Co Ltd included G-EAGI fitted with the V-strut undercarriage of the Home Defence fighter variant. When the firm closed in 1921, chief pilot Herbert Sykes left to continue Avro joyriding on his own account at Kingsbury, Middlesex, with tours in the Midlands each summer, each of his machines being appropriately named Psyche in turn.
  Vickers Ltd opened south of the Thames with G-EACV, ’DS, ’EY and ’EZ at Joyce Green, Kent. Two of these did a roaring trade at Kings Heath, Birmingham, in August and on October 10 another, piloted by Capt Simpson, made commercial aviation history by carrying 333 lb of tinned fish from Newcastle to Turnhouse. Croydon figured as an Avro ‘pitch’ from August 1919 when Aircraft Transport and Travel Ltd started joyriding with G-EAIO - ’IS and Sir Philip Sassoon, who was just about the first owner of a private 504K, commuted to and from Lympne in G-EANN.
  Coastal resorts outside the Avro company’s network were served in 1919-20 by the Eastbourne Aviation Co Ltd with 504L seaplanes and two 504Ks; by the Bournemouth Aviation Co Ltd with five; and by the Navarro Aviation Co Ltd with three. The Bournemouth outfit ran a service to Weymouth and worked inland towns as far as Bath, while Navarro’s machines G-EADY, ’EA, ’EB and ’JP enjoyed lucrative seasons at Southend and Whitstable. Among the first concerns to offer flying instruction was the Cambridge School of Flying Ltd of Hardwick to which record crowds were drawn by F. J. Ottweiler’s aerobatics in E3501/G-EAEC in August 1919. Their other machine E4118/G-EAHL did good business at Hunstanton and during August and September 1919 two new Humber-built 504Ks G- EAGV and ’GIF ran a Harrogate-Hull-Scarborough service for the North Sea Aerial Navigation Company of Leeds.
  Aerial Photos Ltd of Edinburgh, owners of three (later six) 504Ks made a vigorous pleasure flight tour of St Andrews, Rothesay, Dundee, Perth, Berwick and Montrose. They carried 1,509 passengers, one of whom flown at North Inch, Perth, was the young Earl of Kinnoull, who four years later became the owner of private 504K G-EAMZ. The Ayr-Glasgow area was served by G-EADH, 'HY, ’HZ and ’IA of the West of Scotland Aviation Co Ltd, Renfrew.
  Smaller concerns of the period were run by Telford Rogers at Birmingham with G-EAFQ; G-EAHO (H. V. David) crashed at Aberystwyth after only three weeks; C. A. Crichton (Northern Aircraft Transport and Travel Co Ltd) flew ’GZ at Sunderland; and W. G. Pudney toured rural Essex with ’JZ, ’MI and ’RP. Probably the first British ‘executive’ aeroplane was Avro 504K G-EANT commissioned at Brooklands in October 1919 to assist Godfrey-Nash motor racing interests. J. D. V. Holmes, an ex-RAF pilot whose brother F. J. V. was a skilled aircraft engineer, pooled all available cash in May 1919 with the newly demobilised Alan J. Cobham, and bought G-EACL, first 504K sold by the Aircraft Disposal Co Ltd. After its conversion to three-seater by Avro at Hamble, Cobham commenced joyriding at Newbury, Wantage, Oxford and Aylesbury, but two months later ’CL overturned in a hayfield near Northampton, after which the replacement G-EAIB, worked Leicester, Nottingham and elsewhere.

The Lean Years
  Foreseeing the end of the boom, Avro left the joy flight business but the Holmes brothers continued through the winter at Bradford, Middlesbrough and Newcastle, Cobham alone carrying 6,000 passengers. Wing-walking was introduced by F. J. V. Holmes and R. Graham-Woolland at Leicester on August Monday 1919 and served to draw the crowds. G-EASF, destined to become the most famous of all joyriding 504Ks, was first flown at Warrington and Bolton in 1920 under Cobham and Holmes Aviation Co ownership but much of the income came from free flights paid for by local newspapers. When Cobham left to join de Havillands his place was taken by J. C. C. Taylor, an experienced pilot and engineer. Former Avro Transport machines G-EAHZ and ’KX were acquired to work the lucrative South Wales beaches but ’IB was sold. After overhaul at Manchester it was flown to Priory Heath, Ipswich, in 2 1/2 hours by Capt Anderson of the Anderson and Pool Aviation Co on July 2, 1920. To attract custom, fares came down to 15s 6d, a move found expedient by concerns such as J. M. Drysdale’s Oxfordshire Aviation Co which based G-EADU and ’GT at Caversham, Reading; J. Blake’s taxi service between Liverpool and the Isle of Man, flown by G-EAFD during the T.T. Races in June 1920; Ingham and Little (the Border Aviation Co) at Carlisle and Scarborough with G-EANQ in 1920, and at Cockermouth and Heysham with G-EAIA in 1921; Summerfield and Company on the East Coast with G-EADR and ’EB', and A. A. Mitchell (the Scottish Aerial Transportation Company) of Craiglockhart who carried passengers over Edinburgh in G-EAQU, ’QV and four others hired from Aerial Photos Ltd. By this time Croydon joyriding was in the hands of W. G. Chapman (Leatherhead Aviation Services) with the ex-Cambridge G-EAHL. He also sold flights at Reading, Leatherhead, Guildford and Chessington but withdrew from the business when his new 504K G-EBAV crashed at Slough on August 20, 1922. F. G. M. Sparks and E. A. Sullock formed the Welsh Aviation Co Ltd in November 1920 to revive the Swansea trade with G-EAWK, 'WL and ’IFAI but optimism went unrewarded and after one season they were bought out by local turf accountant Evan Williams. Only 71 hours were flown in 1922 and the new owner was drowned with pilot F. Bush when ’WK fell into the sea in the following October.
  Alexandra Park, birthplace of the 504K, housed the Midland Aviation Company equipped with G-EADP, ’GB and ’LE. It was a typical ‘one season’ outfit, taken over in 1922 by the Manchester Aviation Co Ltd which, with a smaller concern called Manchester Airways operated all over Lancashire. Three Avros G-EADP, ’ZW and ’ZX alone survived this ordeal to found the Northern Aviation Co Ltd in 1924. In the south C. L. Pashley (CFI of the Southern Aero Club until 1965) took 504K G-EATU to Shoreham for instruction and joyriding, while a more ambitious project, inaugurated by the Royal Aero Club in July 1921, sought to provide aeroplanes for the use of members. The Aircraft Disposal Co delivered G-EAXY, ’YB and ’ YC, newly overhauled, which were raced enthusiastically at Croydon in September 1921 but lost in accidents soon afterwards.
  Frank Neale (the Essex Aviation Company) who acquired G-EBCK from F. J. V. Holmes in 1923, did well at Epping and also on Margate beach. In the same year J. M. Drysdale’s old machine G-EADU was sold to Renfrewshire Flying Services to join ’JZ at the game in southwest Scotland. They were not alone at Renfrew as William Beardmore and Co Ltd was awarded a Reserve Training contract and purchased G-EAHY from the West of Scotland Aviation Co Ltd, G-EBFV from F. J. V. Holmes and G- EBGY, ’GZ and ’IS newly civilianised by A. V. Roe and Co. These and G-EBXA (a crash replacement) flew hundreds of hours per annum until the three survivors were replaced by Bristol Type 89As in 1927 and sold to the North British Aviation Co Ltd at Hooton for joyriding in 1929. G-EBLA, originally the Reserve Training 504K at Brough, was also sold for joyriding but fell into the sea at Weymouth on June 6, 1928.
  The 1923 Air Ministry Light Aeroplane Trials awakened interest in private flying and several 504Ks were thus used, including G-EAMZ (130 hp Clerget). This came out of storage as a mount for pioneer Avro test pilot P. Raynham in the Grosvenor Trophy Race on June 23. With rear seat faired over he flew round the Lympne-Castle Bromwich-Filton circuit at an average speed of 96-1 mph and came second. In June 1925 ’MZ was sold to the Earl of Kinnoull (whose enthusiasm for the 504K dated from a pleasure flight at Perth in 1919) for whom Beardmore test pilot Maurice Piercy made the delivery flight to Le Bourget where it crashed only a few days later. Flying from Hendon and Brooklands, G-EASB was widely publicised in 1925 as the mount for the first ‘aerial commercial travellers’, (Tellus Super Vacuum Cleaner representatives), flown about the country by J. C. P. Phillips and C. P. B. Ogilvie. G. V. Peck (the Southern Counties Aviation Company) painted up G-EASG as the concern’s ‘A Flight’ and a new machine G-EBKS, built from spares, as ‘B Flight’. Working from Brooklands they were a familiar sight in the south and a third machine G-EAAY was added in 1926. This ‘evergreen’ was soon acquired by F. G. Miles of Shoreham along with G-EBJE which had been at Brooklands for some months as the private aeroplane of racing driver John Cobb. Although he is well known as the founder of Miles Aircraft Ltd, few realise that F. Miles flew over 2,000 hours in Avro 504Ks. In 1927 the Gnat Aero Co Ltd (forerunner of the Southern Aero Club) was formed at Shoreham with G-EAJU, ’TU and G-EBYB and successfully worked the South Coast, a task in which G-EBJE, ’VL and G-AACW of Southern Aircraft Ltd also joined in 1928. ‘Opposition’ in the area was provided by the irrepressible Dudley Watt operating from Ford, Sussex, with G-AADY, ’FJ and G-ABBF. Other prominent members of the fraternity at that time were Messrs Thomas, Griffiths and Rimmer (South Wales Airways) of Porthcawl and Swansea who kept G-EBNH, ’SG, G-AASS, G-ABLV and ’LW in turn in their hillside hangar at Wenvoe; Messrs L. Lewis and L. A. Jackson (later of the Shuttleworth Trust) who ran L. J. Skytrips Ltd in the Home Counties; and Western Aviation Ltd which worked the West Midlands with the blue and cream striped G-EBQR and ’XV.

Renaissance
  Interest in the 504K as a private aeroplane revived in 1926. It was not easy to fly, but once mastered, was a real ‘pilot’s aeroplane’, but unfortunately stayed economically in the air solely by joyriding’s high utilisation. Thus C. L. Kent’s G-EBKR; J. C. Don’s ex-Gnat G-EAJU; G-EBSJ flown at Maylands by Battlesbridge flour miller A. H. Matthews; and L. E. R. Bellairs’ G-EBVL; soon returned to barnstorming, the last at Christchurch with F. C. Fisher. Of unique interest was G-EBWO rebuilt with a 100 hp Anzani radial at Woodley in 1928 by Philips and Powis Ltd for Dr M. C. Wall. After a few months it joined standard 504K G-AAGG at the Phillips and Powis flying school.
  As the decade drew to its close another crop of small operators appeared which included R. J. Bunning at Pontypool with G-EBSM; Midland Aero Flights Ltd with G-EBYE; Inland Flying Services Ltd of Maylands who worked Essex fields with G-AAFE and ’FT; and Aeroplane Services which spent the 1929 season at Southend using G-AAEZ in competition with Surrey Flying Services’ G-EBYW at Shoebury. The latter was sold in 1930 to Aviation Tours Ltd which plied its trade in the west country with some success, took over Western Aviation Ltd in 1933 and expanded its fleet to five - G-EBQR, ’XV, ’YIV, G-AAYM and G-ABAA. Airframes were by that time in very short supply and the last of these grand old biplanes were built from spares by Kent Aircraft Services Ltd who produced seven with private constructor’s numbers K.A.S.l to 7 at Kingsdown, Kent, in 1930- 31; by G. and H. Aviations Ltd at Stag Lane in 1930 (G-ABAA and ’AB), by the Essex Flying Club who built G-ABWK and ’YB in a garage at Orsett, Essex, in 1932; and by C. B. Field who constructed G-ABSL - ’SN, G-ACAU and ’AV at Kingswood Knoll, Surrey, in 1932-33. The Kent Avros flew at seaside resorts, one at Ramsgate piloted by E. Bicknell of Thanet Aviation Ltd and another at Gravesend by P. H. Meadway. The Essex Avros, intended for a club at Abridge, went instead to Springfield, Chelmsford, in a second vain attempt to form a club. C. B. Field’s machines were all sold to small concerns and on September 24, 1932, G-ABSN (130 hp Clerget) forsook its pitch at Herne Bay when London and Provincial’s pilot Pegg averaged 59 mph in the Hillman Trophy Race from May lands to Clacton and back and came 7th.

Grand Finale
  The useful life of the old 504K ended in the mid-30s in service with the big names of joyriding. The first of these came into existence on August 25, 1921, when the Holmes brothers reformed as the Berkshire Aviation Co Ltd (later restyled Berkshire Aviation Tours Ltd), operating initially at Porthcawl. Here A. L. Robinson joined O. P. Jones (later famous as the bearded Imperial Airways and BOAC Captain) on the payroll. The latter had been with the Holmes since February 1920, first flying commercially for them at Carlisle the same month. He, alone had carried 10,000 passengers by the end of 1921 (8,000 in G-EASF') but left to form his own company with A. N. Kingwill in 1922, using Avros G-EADH and G-EBCB. Robinson (who succeeded in carrying 155 passengers in one day in G-EAKX at Wells on May 14, 1922) also went to Imperial Airways in 1924, being replaced by J. D. Parkinson who alone carried 34,000 passengers, 10,000 of them for Berkshire in 1925. Overhauls continued at East Hanney where six more 504Ks were stripped and rebuilt as G-EBCK, ’EV, ’IN, ’KB, ’KR and ’KX before 1926, the year the firm moved to Witney Aerodrome, Oxford. Scarcely any part of England and Wales escaped their attention and the firm’s passenger figures to the end of 1925 exceeded 32,000. Berkshire amalgamated with Northern Air Lines in May 1929 to form Northern Air Transport Ltd with 16 aircraft, the largest 504K fleet since 1919. James Orrell, later chief test pilot of A. V. Roe and Co was the pilot of Northern’s oldest Avro, the famous G-EASF, at Rochdale in 1931.
  Surrey Flying Services Ltd, formed at Croydon in 1922 by A. F. Muir and W. F. Grant with two Clerget Avros, G-EAWI and ’WJ (in which Capt Muir made charter flights to Cardiff, Dublin, Brussels and the battlefields) were precursors of a large fleet of blue and silver 504Ks which became an integral part of the Croydon scene for more than a decade. Short trips were reduced to 5s, countless thousands of which were sold by the indefatigable Joe Chamberlain at the Purley Way gate. In addition to 13 for its own use the firm also reconditioned 504Ks for other companies and as late as 1934 their last serviceable machine, G-AAAF, was still ambling off Croydon’s turf in an aroma of castor oil to return to the accompaniment of never-to-be-forgotten blips of the rotary engine and with the wheels still spinning.
  The only other firm to operate on any scale was the now almost legendary Cornwall Aviation Co Ltd formed in September 1924 by Capt Percival Phillips DFC and F. L. Hill, garage proprietors of St Austell. Their first machine G-EBIZ, resplendent in pillar box red and built by Berkshires at Witney, worked Margate beach. As business increased, other red Avros flew from fields all over the Home Counties and by 1930 the fleet consisted of G-EBIZ, ’NR, ’SE, G-AAAF and ’ YI. Each winter they were overhauled in the garage at St Austell and in the spring flew out of a nearby field at Ventonwyn. Maintenance ‘on location’ was very difficult because the man-in-the-street who saw a partly dismantled aeroplane took it for granted that an accident had occurred. To prevent unwarranted loss of trade the Avros were taxied under a tree at nightfall and a spare engine installed secretly by means of block and tackle in the light of car headlamps. It spoke well for the superannuated 1913 design that 20 years later it could still make up to 40 take-offs a day, every day, and take the punishment involved in miles of taxying over rough ground. In the summer pilots and engineers lived a nomadic existence and flew the Avros from field to field laden with tool chests and spares, and with bedding, tents and passenger ladders lashed to the undercarriage and between the interplane struts.
  In 1932 they teamed up with Sir Alan Cobham’s National Aviation Day Display but at the end of the 1933 season the Cornwall fleet disbanded to make way for Capt Phillips’ new company. At the time of his death in 1938 Capt Phillips had carried over 91,000 passengers, nearly all of them in G-EBIZ.
  ‘Cobham’s Circus’ succeeded in its aim of fostering airmindedness largely through the imaginative use of the red Cornwall 504Ks which enabled passengers to take part in the events. In 1933 the silver and black fleet of the North British Aviation Co Ltd was enlisted to enable two separate tours to take place simultaneously. Founded at Hooton in 1929 by E. E. Fresson and L. J. Rimmer with G-EBGZ, ’IS and ’XA, it normally worked Cheshire and Lancashire but in 1931 made a Lakeland tour with a base at Keswick. In 1933 L. J. Rimmer and W. ‘Jock’ Mackay bought up the remaining stock of the late Northern Air Transport Ltd and the augmented fleet of fourteen Avro 504Ks was used by Cobham again during the 1934 season. A series of accidents in which Mackay was killed in an Avro 504N left them with only the seemingly indestructible G-EASF with which to finish the 1935 season. At the end of that year the Air Ministry refused to renew Certificates of Airworthiness for rotary engined aircraft and the heyday of the Avro 504K in Britain was over.
  

Avro 504K (overseas)

  In 1919-20 the British Government made each Dominion an Imperial Gift of surplus Avro 504Ks and other aircraft, and during the next 12 years large numbers of additional 504Ks were stripped, overhauled and test flown at Croydon by the Aircraft Disposal Co for military and civil use overseas. Vickers Ltd and A. V. Roe and Co were also heavily engaged, the latter completing one hundred 504Ks in 1921 alone. Manufacturing rights were also sold in Japan and elsewhere.

Australia
  Equipment of the Australian Flying Corps in 1920 included 48 Imperial Gift Avro 504Ks. They carried A3 serials and later served with the RAAF until replaced by D.H. Moths in June 1928. At least ten others were acquired by short lived joyriding outfits such as Kingsford Smith’s Diggers’ Co-op Aviation Co Ltd but few made money although Normal Brearley flew 80 passengers Perth-Kalgoorlie in two machines (100 hp Gnome Monosoupape) in October 1919 and C. A. Butler carried 62 at Adelaide. The Australian civil register was not established until June 1921 and all flew in old Service colours.
  Avro manufacturing and sales rights were vested in H. E. Broadsmith, former manager of the Manchester works, who left for Sydney with four 504Ks which had been allotted (but never carried) British marks G-EAIV - ’IY in the name of the Australian Aircraft and Engineering Co Ltd which Broadsmith had formed in association with Capt Nigel Love and Lt Warneford. He also took components for 15-20 additional 504Ks. On arrival three were converted to three-seaters and fitted with 130 hp Clerget engines at Mascot, where the first joyride took place on January 9, 1920. They carried no markings other than ‘AVRO’ and AAEC titling. Capt Love used the first machine for the first inter-city flight to Melbourne and a tour of the outback for a paint firm (September 7 - October 18, 1920). He also won the handicap section of the first Australian Aerial Derby on November 27, 1920.
  The company’s second 504K (first flown as a 504L at Manly Bay, Sydney) was exhibited at the Brisbane Show and afterwards carried several thousand joyriders at Eagle Farm Racecourse, piloted by F. L. Roberts who on June 26, 1920, flew the first air mail 87 miles from Lismore to Tenterden. Capt Wilson in the third Avro dropped foodstuffs to valuable sheep in flooded country, but of the three Clerget machines, only G-EAIV/G-AUCB survived to receive civil marks in 1921. Lt Adair delivered the fourth (110 hp Le Rhone) to the Queensland Northern Graziers Association at Brisbane on August 13, 1920, after a record flight of 240 miles between Newcastle and Grafton. This machine became G-AUBE in 1921.
  Broadsmith began the erection of 504Ks from imported parts in 1921 and fitted some of them with Sunbeam Dyak engines. The first, G-AUBG for the infant QANTAS, carried 283 passengers and flew 7,400 miles in a few months, while the second, built for P. Hogarth, was delivered 1,845 miles to Clio Station, North Queensland by J. Treacy in 20 flying hours. It was eventually registered to A. J. Driver, Brisbane, as G-AUEO in 1924. The third and fourth, believed G-AUCD and ’CE (Clerget engines), were followed by seven more Dyak 504Ks including G-AUBS for Percy Heyde of Nimmitabel, NSW, and two unregistered examples for inter-railhead connections of Auto Aero Services Ltd.
  In 1922 AAEC received a contract for six 504Ks (Clerget) for the RAAF. These were built at Mascot from selected Australian timber which proved equally strong for a weight penalty of only 80 lb. Serials were A3-48 to A3-53 and the first, named Mary by the wife of the Prime Minister, was handed over at Mascot on June 16, 1922, for acceptance tests by the well known Bristol designer Sq Ldr F. S. Barnwell.
  The 504K played a notable part in later Aerial Derby Races as in 1922 at Sydney when Dyak Avros G-AUBJ, ’CZ and a third (believed G-AUDM) with improved V-strut undercarriage, unbalanced rudder and triangular fin, were on the line. Capt E. W. Percival, who had earlier fitted G-AUDA with a 90 hp RAF IA, came fourth in the 1924 Derby in G-AUEP which had been modified to take the big 220 hp Hispano-Suiza engine, competing against H. C. Miller who had replaced the Dyak in G-AUDR by a 100 hp Curtiss K-6 taken from a Curtiss Seagull, a combination which won the major prizes.

Belgium
  Demonstrations at Brussels in August 1920 by Avro 504Ks G-EAHX and ’VD led to the placing of Contract 45/21 with Vickers Ltd in 1921 for 12 machines to re-equip the 8th (Flying School) Group of l’Aeronautique Militaire. The order was made up of six converted by A. V. Roe and Co at Hamble and flown out with Belgian civil marks, and six redundant Avro Transport Company machines originally converted for joyriding in 1919. A further 38 obtained from the Aircraft Disposal Co in 1922 included 18 flown from Croydon to Brussels in British civil marks November 1921 - July 1922. One other, O-BADB, was flown out by A. H. Forson for the pioneer airline SNETA on March 24, 1921.
  Further needs were met by the construction of 27 Avro 504Ks (80 hp Gnome or 130 hp Clerget) under licence at Evere by SABCA. A-51, first of these, was specially equipped and flew inverted for 2 min 27 sec piloted by G. F. van Damme of the Belgian Army Flying School, Wevelghem. Thirteen outdated SABCA 504Ks were sold for civil purposes 1934-38.

Canada
  In 1918 a contract placed with Canadian Aeroplanes Ltd, Toronto, for 500 Avro 504Ks (130 hp Clerget) was ended by the Armistice when only two had been completed. Their V-type undercarriages had a third bracing strut and differed considerably from the British original.
  After the war Canada received 63 Imperial Gift 504Ks which, from August 16, 1920, were used in lettered markings at Camp Borden, Ontario, for pilots’ refresher courses. Some were employed by the Air Board for forestry patrol or aerial photography, G-CYAC making the first Canadian Air Force survey of Ottawa. Survivors of the 49 Avro 504Ks at Camp Borden at the beginning of 1922 were reconditioned by the Lauren tide Air Service, Quebec, in 1924 and others were reworked by Canadian Vickers Ltd and the Ottawa Car Co, some as Avro 504Ns.
  Seven 504Ks (110 hp Le Rhone) were imported privately by the Canadian Aircraft Co Ltd of St Charles, Winnipeg, for conversion to three-seaters for joyriding. One of these, G-CAAE, came from the London Flying Club, Hendon; and G-CAAR made a 400 mile electioneering trip through Manitoba during 1920. On October 15-16, 1920, H. Dougall and F. H. Ellis flew G-CABV 487 miles from Winnipeg to The Pas, Manitoba, the longest commercial trip in Canada up to that time. Named Thunderbird by the Cree Indians, ’BV was the first aircraft to fly north of latitude 53 degrees.

China
  Sixty Avro 504Ks in batches of 20 and 40 were ordered by the Chinese Government from Vickers Ltd in 1919 and delivered to Peking. The twenty machines, ordered on August 12, were mainly unused Harland and Wolff-built machines, 18 of which were exported with British Certificates of Airworthiness dated March 10, 1920, and two others as instructional airframes or spares. First deliveries, which reached China in July 1920, were used at the Nanyuan Training School, Peking, but a number were seized by local warlords and only a few remained in Government hands at Tsing Ho in 1923.

Denmark
  Six Avro 504Ks bought from the Aircraft Disposal Co by the Danish Navy, arrived at Copenhagen by sea on December 29, 1920, and were erected at the Naval Flying School, Avedore. They moved to Kastrup in 1923 and to Ringsted in 1926. Three were lost in crashes but two of them, serials 104 and 106, survived for conversation into 504Ns in 1928 at the expense of 105 which was broken down for spares.
  Det Danske Luftfartselskab (DDL) obtained three 3-seat 504Ks from the same source for joyriding in 1919. Two of them, H2549 and H2556 (110 hp Le Rhone), already certificated in Britain as G-EAJE and JF to DDL pilot Capt J. D. Atkinson, reached Copenhagen by sea on August 8, 1919, but the third (unregistered) was shipped from Leith to Iceland in charge of Capt C. Faber who began pleasure flying at Reykjavik on September 3. Operated by Flugfelag Islands (not the later company of that name), the machine made a landing at the remote Westmann Islands and carried 140 passengers in three weeks. Faber then returned to Denmark and F. Frederickson used the Avro for fishery patrol in 1920.
  Only the first of Atkinson’s machines, which had been re-engined with a 150 hp Bentley B.R. 1, received a Danish civil registration but when joyriding petered out in 1921 both were acquired by the Danish Army which also took over the repatriated Icelandic machine in June 1922. They were re-serialled Avro 1, Avro 2, and Avro 3 but the first two crashed at Klovermarken early in 1922 and were replaced by two new Avro 504Ks bought from A. V. Roe and Co without engines. Bentley B.R.ls were installed on arrival and all three remained in service until replaced by D.H. Moths in 1929.

Estonia
  Aeronaut AS inaugurated an airmail service between Reval and Helsinki, with Avro 504Ks (130 hp Clerget) on February 7, 1920. Landings were made in the ice-bound harbours by British pilots Emery and Swatridge. Nine Avro 504Ks (130hp Clerget) were acquired by the Estonian Air Force in 1919, serials 12, 14, 15, 18-23, known former identities being 15/E9467, 18/E3145, 21/E9493. A further four (serials 72-75) were acquired in 1920.

Finland
  One Avro 504K G-EBNU/E448 was supplied by the Aircraft Disposal Co to the Finnish Air Force in 1926. It was issued with a British C of A on April 23 of that year, was delivered on September 22, and flew in Finland with a ski undercarriage. Given serial AV-57 it was withdrawn from use after an accident on November 11, 1930, but was then placed in storage, for many years at the Finnish Air Force Museum at Vesivehmaa. In 1968 it was transferred to Rissala for restoration and in 1979 was put on permanent display at the newly opened Aviation Museum of Central Finland, Tikkakoski.

India
  The Imperial Gift of 100 aircraft for India included 18 presented to the Indian States. Many were Avro 504Ks, surplus examples of which were returned to the Public Works Dept, Aviation Branch, and then given to individuals attempting to open up commercial aviation in India. Their subsequent activities are obscure and none appeared in the register of Indian civil aircraft.

Ireland
  In 1921 the Irish Air Corps purchased five Avro 504Ks from the Aircraft Disposal Co, and one from the Central Aircraft Co, Northolt, for reconnaissance, leaflet dropping and train escorting. They afterwards formed the equipment of ‘A’ Flight of the flying school at Baldonnel.
  Joyriding by civil 504Ks occurred only in 1932 when two aircraft bought from Northern Air Transport ltd, Manchester, were operated on a roving basis by Irish Air Lines of Waterford.

Japan
  A British mission to the Imperial Japanese Navy in April 1921 led by the Master of Sempill, took with it twenty Avro 504Ks. On arrival, one serialled 108 was displayed at the Yoyogi parade ground, Tokyo, to publicise the opening of a waterside training base at Kasumigaura also suitable for Avro 504L seaplanes. In the same year, A. V. Roe and Co sold 504K manufacturing rights to Japan for £30,000 as well as 48 complete aircraft to the Japanese Army, including eight redundant 1919 joyriding conversions. 250 Japanese Avro 504Ks were built by the Nakajima Hikoki Seisaku Sho (Nakajima Aircraft Manufacturing Co) at Ohta-Machi, Tokyo, and 30 by the Aichi Tokei Denki Kabushiki Kaisha (Aichi Watch and Electric Machinery Co) at Nagoya. Some were fitted initially with 150 hp Bentley B.R. 1 engines but as these wore out they were replaced by 110 hp Le Rhones built under licence by the Tokyo Gasu Denki (Tokyo Gas and Electric Industry Co). Over 75 flew in civil markings alone, at least three were still active in 1928, and in 1934 a solitary example was still used by Nihon Koku Kabushiki Kaisha (Japan Air Transport Co), Tokyo.

Malaya
  One Avro 504K was shipped to Penang in 1920 for a Chinese, Tsoe K. Wong, who had built and flown biplanes of his own design at Shoreham 1913-14. The 504K stalled on a climbing turn on its first take-off and the pilot L. J. Pugh, late of the Avro Transport Company, Southport, was killed.
  
Mexico
  At least one Avro 504K, E9441, was imported from the UK and a modernised version resembling the Avro 504K Mk.II was built under licence at Balbuena for the Mexican Air Force. These new aircraft were dubbed Avro Anahuacs and served with the Air Force flying school at Balbuena 1922-30 after which some were sold for civil use. During their careers they were fitted with a variety of engines, including the 80 hp Gnome, 90 hp Curtiss OX-5 and 150 hp Hispano-Suiza.

Netherlands Indies
  Thirty-six Avro 504Ks (130 hp Clerget) delivered to the Netherlands Indies Army Air Arm 1919-22, were supplemented by sixteen updated machines (110 hp Le Rhone) built in the Air Arm’s own workshops at Andir from 1924. Those bought in the UK were delivered by Vickers Ltd in three batches of 12, to contract 269/19 on May 31, 1919; to 453/19 on December 18, 1919; and to 640/22 on November 8, 1922. They were stationed at Kali Dvatch and bore the serials A-21 to A-56, one was formerly H9769. The locally built machines had serials in the range AL-57 to AL-73 and all surviving 504K aircraft were re-engined with the 130 hp Armstrong Siddeley Mongoose in 1933. The type remained in service until 1936.

New Zealand
  As she had no Air Force, only two of the twenty-one Imperial Gift Avro 504Ks accepted by New Zealand in 1920 were retained by the Government for official use. They were based at Sockburn, Christchurch, and the rest distributed on loan to the Canterbury Aviation Company, Sockburn; the New Zealand Flying School, Auckland; and the New Zealand Aero Transport Company, Timaru. A few of these eventually received civil marks.
  Four 504Ks (D6243, E4153, E4237, E4242) had been bought earlier from the Disposal Board in England by Capt Euan Dickson of the Canterbury Aviation Company. These arrived by sea on January 14, 1920, and E4237 was flown Sockburn-Fairlie-Mt Cook with two passengers on May 21, by Capt Dickson who also made the first flight across Cook Strait while en route Sockburn-Trentham, Wellington, in D6243 on August 26. The company’s fleet rose to eleven 504Ks when seven others were loaned by the Government. On December 23, 1921 E9432 High Jinks was flown by Capt L. Brake via Napier to Gisborne where pleasure flights were made from Waikanae Beach.
  The New Zealand Flying School received one 504L, H2990, and five 504Ks, four of which were converted into three-seaters and two into 504Ls.
  Capt R. Russell flew one from Auckland to Wanganui and continued in F9745 to New Plymouth on October 5, 1920. There it spun in from 200 ft on November 9, the local mayor, pilot and another passenger being killed. The New Zealand Aero Transport Company also received six machines, all of which were 504Ks and included E9429 which made a pioneer flight from Wellington to Nelson on November 11, 1921, piloted by Capt Fowler. Another of the firm’s pilots, Capt M. W. Buckley, acquired H5241 and named it Blazing Arrow. Trading as the Arrow Aviation Company he undertook joy flying at the 1923 Hokitika Exhibition, and made the first photographic flights over the Franz Josef Glacier. Leaving Greymouth on June 4, 1924, he also made the first flight from Westland to Canterbury, crossing between Mt Rolleston and Mt Frankton at 7,500 ft and covering the 128 miles to Wigram in 1 3/4 hours.
  In 1923 the New Zealand Government formed an air arm by purchasing the assets of the Canterbury Aviation Company together with Sockburn Aerodrome which it renamed Wigram. Initial equipment included E3137 and Hl 965, retained by the Government in 1920, and the Canterbury machines, all of which reverted to unprefixed military serials. Many served later with the NZ Permanent Air Force for which six replacement aircraft were erected locally in 1925 using new airframes obtained from A. V. Roe & Co and engines previously supplied as part of the Imperial Gift.

Norway
  Two ex-RFC 504As (80 hp Le Rhone) erected at Kjeller by the Norwegian Army Air Force on February 14, 1918, were allotted serials F-1 and F-7 (later changed to 101 and 103). The former crashed at Kjeller on September 30 and was rebuilt with a 90 hp Thulin (Swedish-built Le Rhone). The Army then acquired three Avro 504Ks in England. Two with 100 hp Sunbeam Dyak engines which arrived at Kjeller on November 2, 1920, were commissioned in July 1921 as 103 (reallocation) and 105. The third 504K (110 hp Le Rhone) was presented by explorer Roald Amundsen but crashed on its first test flight on June 30, 1922, both occupants being killed.
  The first civil flying school was started at Gardermoen in the summer of 1919 by Norsk Aeroplanfabrikk AS with one unregistered Avro 504J (100 hp Gnome Monosoupape), and at least one other 504A was also imported. Intended for naval training, the identity of the latter has not survived but after storage at Tonsberg, 1919-26, it was fitted with a 140 hp Hispano-Suiza HS 8Aa water-cooled engine for the firm’s proprietor Lt Christian Hellesen. Registered N-5, its end came swiftly and Hellesen then acquired two 504Ks one being 101, the original Norwegian Army 504A. Both were rebuilt with Hispano engines and were registered N-29 and N-37 respectively, the latter having enclosed cockpits and ski undercarriage.

Portugal
  Thirty Avro 504Ks (110 hp Le Rhone) ordered by the Portuguese Government from Vickers Ltd under Contract C.l 113/23 dated November 10, 1923, were entirely reconditioned at the Manchester works of A. V. Roe and Co and allotted constructor’s numbers accordingly. Bearing serials 1-30, they were all delivered in Portugal by May 20, 1924, and many were still in use at the Cintra flying school in 1927 and four were flying with the Grupo de Esquadrilhas de Aviacao ‘Republica’ as late as 1934.

South Africa
  Imperial Gift 504Ks formed the equipment of SAAF training, photographic and artillery spotting units until replaced by Avro 504Ns in 1927. For pleasure and charter flying three Le Rhone engined three-seaters were shipped to Johannesburg in July 1919. These had been allotted British marks G-EAFU, ’FV and ’FW in the name of the South African Aerial Transport Company, sole Avro agents for the territory. Named The Rand Queen, Natalia and Orangia at Baragwanath Aerodrome on October 25 and piloted by Maj A. M. Miller, Capt Ross and Capt Rutherford, they penetrated to all parts of the Union. Rutherford gave pleasure flights in the Northern Transvaal to former Boer War leaders Gen T. E. Botha and Capt de Jager, while Miller made a long distance flight to Kimberley and on November 15 flew to Durban for the Johannesburg Star, dropping 1,200 copies of the newspaper en route. One of two additional machines acquired in December 1919 was flown by Rutherford to Bulawayo where it was named Rhodesia in June 1920 and twice filmed the Victoria Falls. One Avro hired by the Union Air Force made unsuccessful rain making experiments on October 5, 1920, by dropping sand on clouds at a height of 5,000 ft.
  Although Natalia had rescued the crew of Handley Page O/7 G-EANV when it crashed at Beaufort West on February 23, 1920, and over 5,000 passengers had been carried in 15 months, the company was wound up and surviving Avros Natalia, Griqua and Rhodesia auctioned. Two continued operations with former SAAT pilots of the Ross-Thompson Aviation Company and on March 24, 1921, Maj Honnett established a South African commercial height record by flying one of them over the Drakensberg Range with two passengers and luggage. The third crashed on take-off from Baragwanath on December 15, 1920, killing purchaser S. Brick, his wife and pilot F. V. Preller. Ross-Thompson 504Ks barnstormed for 18 months before sale in Southern Rhodesia where one crashed at Rusapi through elevator control failure in 1921.

South America
  Argentina accepted the gift of one Avro 504K from the Aircraft Disposal Co in 1921 and purchased eight more on condition that the firm supplied an instructor for the flying school at El Palomar. A tenth 504K (110 hp Le Rhone) was used by the Tucuman Civil Aviation School under Capt S. H. Holland, but this was written off at Lules in April 1920.
  Five Avro 504Ks (100 hp Gnome Monosoupape, 110 hp Le Rhone or 130 hp Clerget engines) bought in England for the Brazilian Naval Air Service were joined by twelve others in 1921. At least fourteen were acquired by the Chilean Government, including ten reconditioned machines supplied by A. V. Roe and Co. in 1921 were used by the Military Aviation Service flying school at Lo Espejo and included as least two unused Avro Transport Company civil conversions and one aircraft, serial 82, named Curico. In 1924 the Guatemalan Air Force also purchased a number of Avro 504Ks.
  The Peruvian Ministry of War placed a third and final order with Vickers Ltd on March 13, 1922, for four Avros 504K trainers to Contract C.137/22/160, delivery of which was completed on August 3, 1922. They were erected on Lima Racecourse and flown to the training base at Las Palmas. These and machines from two earlier batches of four in 1920-21 to Contracts 275/20 and 34/21 were still used for training by the Peruvian Navy in 1925. Four Avro 504Ks were in use by the Uruguayan Air Force at San Fernando Aerodrome, Montevideo, in 1920.

Spain
  One Avro 504K overhauled at Ramble by A. V. Roe and Co was flown to Spain in September 1919 by Capt Truelove, had red mainplanes and yellow fuselage, and was maintained by the Air Force for the personal use of King Alphonso. In addition around 50 machines were bought by the Spanish forces, including 24 delivered to Military flying schools in 1923 and 20 acquired by the Spanish Royal Naval Air Service, four of which were obtained from the Aircraft Disposal Co. in 1925 and based in Barcelona. Five ex military aircraft were later civilianised, one as M-AIAI in June 1924. Another seven civil aircraft, bought in England by the Compania Espanola de Aviacion, were used to train military pilots at Albacete. Some 504Ks were still in use in the Republican flying schools 1937-1938.

Sweden
  The first two Swedish Avro 504Ks (110 hp Le Rhone), E3115 and H1955, were imported by the P.O. Flygkompani which operated from Barkaby and bore the initials of founder Lt Per Oscar Herrstrom who employed several British pilots including G. L. P. Henderson and A. B. H. Youell. Although surveyed by the Swedish authorities on July 11, 1919, and allotted civil marks S-AAC and ’AD, they flew with RAF serials and the letter S on the fuselage, and visited many provincial cities, taking off from deep snow in 25 degrees of frost. Engines were warmed for starting by a lighted blowlamp placed in the engine bay. An anonymous 504K (130 hp Clerget), flown out by Capt Saunders in October 1919, was not approved at survey on December 18 and not used. One machine flown temporarily as a seaplane and three others used in North Sweden in 1921 are discussed in the Avro 504L chapter.
  Two 504Ks (130 hp Clerget) ordered from A. V. Roe and Co by the Swedish Navy on October 27, 1923, were shipped from Hull on January 18, 1924. Numbered 6 and 7 (6 on skis) they were joined later by three others (believed 8, 9 and Iff) ordered on September 22, 1924. After the formation of Flygvapnet in 1926 they were renumbered 064 and 072-075 under the designations Sk 3. When 074 was struck off charge on June 30, 1928, it was auctioned at the Ljungbyhed Flying School and almost certainly became civil as S-AABT two weeks later.

Switzerland
  Avro 50Ks G-EAKR and ’KV (130 hp Clerget), overhauled by A. V. Roe and Co at Alexandra Park in August 1919 for the Swiss Aero club, were ferried via Hounslow on September 17, 1919, by Capts E. Bradley and H. M. Goode. G-EAKV arrived at Lausanne three days later via Paris, Dijon and the Jura Mountains, but 'KR was damaged beyond repair in a forced landing at Les Laumes-Alesia in the Cote-d’Or on September 20. G-EAKV crashed while avoiding high tension cables while joyriding at Nyon on November 2 but was rebuilt for the Lausanne Aero d’Aviation. The school erected a second Avro (110 hp Le Rhone) from spares. It first flew on February 21, 1920, piloted by Bradley.

United States
  Flights over Washington by Col C. F. Lee in Avro 504J 'C4312 during 1917 were followed by inspection by the Dayton-Wright Airplane Company at Dayton, Ohio, and evaluation at McCook Field under project number P.25. The result was an order for 52 Avro 504Ks (100 hp Gnome Monosoupape or 80 hp Le Rhone) for the American Expeditionary Force 3rd Instruction Center at Issoudun, France, in July 1918. After the war they were shipped to the USA and taken over with all available spares by the Interallied Corporation, one forming the only British exhibit at the Chicago Aero Show in January 1920. A Miss Nellie Brown Duff bought one but the majority were sold to barnstormers, not the least of whom as Charles Kingsford Smith (later Air Commodore Sir Charles Kingsford Smith) who in 1920 toured California with a 504k of the Moffett-Starkey Aero Circus as pilot and stunt man. In June 1920 Lts Runser, Turner and Freeland flew around the USA in a Clerget Avro with the intention of giving flights in every State, and early in the following year the Lawrence Sperry Aircraft Co Inc acquired all remaining stocks from Interallied. As late as 1928 there were still fifteen on the US civil register, at least two of which were preserved, NC5918, originally H2453, restored to flying condition as N8736R by Cole Palen of Old Rhinebeck, NY, but sold to the Canadian National Aeronautical Collection as G-CYFG in 1966 and NC710 kept in the Thompson Products Museum, Cleveland, Ohio. The latter had a 504L fin and last flew at Arcola Airport, New Jersey, in 1936. A third 504K, ex D8971, stored for many years in Connecticut was sold to the RCAF in 1961 and later ilew as G-CYCK. A fourth machine, ex B3182, stored in Mexico until 1968, made its first post-restoration flight at Boise, Idaho, in August 1972.

USSR
  Copies of the Avro 504K known as the U-1 Avrushka were built in Russia, using as a pattern an example shot down by the Red Army during the civil war. The first U-1s were produced for the VVS (Air Force) in 1921 and 1922 by the GAZ 5 “Samolet” state aircraft factory in Moscow while the GAZ 3, later GAZ 23, “Krasnyl Letchik” factory in Leningrad, now St. Petersburg, built 664 U-1s and 73 float equipped MU-1s between 1923 and 1930. Engine: 120 hp M-2 (Rhone copy). In December 1925 there were 176 U-1s and 10 MU-1s in service and in December 1930 there were 269 and 44 respectively. One went to Dobrolet in 1928 for spraying trials (reg DL-16 8.28, later CCCP-110, c/n 59/339), it crashed in 1929 and was replaced by another CCCP-195 used until 1931. Both were ex VVS. Others were used by the civil aviation schools (Aviakhim).


Avro 504L

  First peace-time 504K variant was the Avro 504L training seaplane. The prototype conversion, C4329, used two wooden, pontoon-type, single-step main floats, each attached to the fuselage by two steel struts, as well as tail and wingtip floats bolted directly to the main structure. A large curved fin was fitted to compensate for the extra keel surface forward and the fairing of the fuselage sides was improved to conform more closely to the shape of the cowling. To give a reasonable take-off performance the higher powered 130 hp Clerget was fitted and trials conducted at Hamble in February 1919 led first to the fitting of a four-bladed airscrew and the removal of the small wingtip floats. Later the main undercarriage was strengthened by means of an additional strut to the rear of each float.
  The Avro 504L did not meet any RAF requirement and was not adopted; nevertheless the Avro company built a considerable number of float undercarriages. The Hamble works also produced seven short-range float-equipped three-seaters for the Avro Transport company. Still more power was needed and a proposal to fit the new 170 hp A.B.C. Wasp I radial was turned down after trials with this engine in K-147, a ‘guinea pig’ 504K from the same production batch. The 150 hp Bentley B.R.1 rotary therefore became the standard engine and drove a two-bladed airscrew.
  G-EANB, last of the seven, was certificated too late in the season to be gainfully employed but the other six were all used for joyriding. Piloted by Capt F. Warren Merriam one worked the Isle of Wight resorts and Hayling Island, and the others went to Paignton, Devon. Flights over Torbay and to Teignmouth proved very popular and 250 passengers were carried during August-September 1919. On August 25, two 504Ls (in all probability K-145 and G-EAJX), flew along the South Coast en route to an autumn joyriding season at the First Air Traffic Exhibition, Amsterdam. One refuelled in Dover Harbour but the other was forced to alight off Ramsgate with petrol shortage and had to be towed in. Their replacements G-EALH and ’Ll were withdrawn to Hamble but K-146 (Capt Evans) was wrecked off Alderney in fog on October 5 while carrying newspapers to Guernsey.
  Operations begun on Windermere under C. Howard Pixton on August 4, 1919, were quite remarkable. His aircraft were not true 504Ls but float-equipped 504Ks (130 hp Clerget) and without the third undercarriage strut. In common with the majority of Avro Transport Company machines at that time, they flew with enlarged Service markings, in this case H2581 and ’82 (later G-EADJ and ’DK). They used the slipway and hangar at Bowness formerly occupied by the Lakes Flying Company and continued the lucrative pleasure flights pioneered eight years earlier by the Avro-built Water Bird. The suspension of night mail boat services to the Isle of Man also gave Pixton the opportunity of making twelve 90 minute early morning crossings to Douglas with 3 cwt parcels of the Daily News.
  The Eastbourne Aviation Co Ltd embarked on a South Coast joyriding season of its own and produced six float-equipped 504Ks. These were also without the third undercarriage strut, and the three occupants sat one behind the other in separate cockpits. The enterprise ended late in 1920 with a seaplane race as grand finale at Hove, Sussex, on August 19 during which G-EAJH sank with a collapsed undercarriage. Maj J. P. B. Ferrand carried 350 passengers in the former Windermere machine G-EADK at Folkestone in 1920 but Avro waterborne activities then ceased round the British Isles. In 1921 the Aircraft Disposal Co Ltd sold the new production 504L G-EANB and two others (almost certainly H1911 and 72) in Sweden to Kungl Vattenfallsstyrelsen (Royal Waterfalls Committee) as S-IAA, ’AB and ’AG. They were used in connection with power station construction in North Sweden. Later two were flown inside the Arctic Circle for seven months by Gosta Hultstrbm and Robert Holmen who made 106 return journeys between Projus and Suorva, flew 23,820 km in 202 hours 53 minutes flying time and carried 362 passengers plus 6,681 kg of mail. One Eastbourne 504L, G-EASD purchased for £400 by Ing G. Spaak, also went to Sweden in 1921.
  Activities elsewhere were confined to idyllic flights from Bermudan beaches in 1920 by two 504Ls of the Bermuda and Western Atlantic Aviation Co Ltd; from Manly Bay, Sydney Harbour, by one of the Australian Aircraft and Engineering Company’s imported machines (without dorsal fin) and later by two Imperial Gift 504Ls of the RAAF; at Mission Bay, Auckland, by three Imperial Gift aircraft of the New Zealand Flying School; in Canada where a few Imperial Gift float undercarriages were brought into use to enable 504Ks to operate from lakes on forestry patrol; and at Valparaiso where three 504L trainers (130 hp Clerget) were used by the Chilean Naval Air Service.
  A British Mission led by Col the Master of Sempill, sent out to advise the Imperial Japanese Navy in 1921, took with it a selection of British machines including ten Hamble-built Avro 504Ls. Maj Orde-Lees and Mr H. Crisp trained the first Japanese naval pilots on these at Kasumigaura, near Tokyo, from which on September 3, 1921, they made a mass formation flight to escort the Crown Prince’s warship and all alighted in Yokosuka Harbour. When Japan purchased the manufacturing rights from A. V. Roe, Bentley-powered 504Ls were built for the Navy by Nakajima. They were without the strengthened undercarriages and their performance deteriorated considerably when the B.R.ls wore out, the only available replacement engine being the licence-built 110 hp Le Rhone. One Avro 504L remained in service with the Japan Air Transport Research Institute of Osaka until 1927.


SPECIFICATION AND DATA
   Manufacturers:
   A. V. Roe and Co. Ltd., Hamble Aerodrome, near Southampton, Hants.
   The Eastbourne Aviation Co. Ltd.
   Nakajima Hikoki Seisaku Sho (Nakajima Aircraft Manufacturing Co.), Ohta-Machi, Tokyo, Japan
   Power Plants:
   One 110 h.p. Le Rhone
   One 130 h.p. Clerget
   One 150 h.p. Bentley B.R.I
   Dimensions:
   Span 36 ft. 0 in. Length 32 ft. 1 in.
   Height 11 ft. 4 in. Wing area 330 sq. ft.
   Weights: Tare weight 1,408 lb. All-up weight 2,006 lb.
   *Performance:
   Maximum speed 87 m.p.h. Cruising speed 75 m.p.h.
   Initial climb 650 ft./min. Endurance 2 hours
   *With 130 h.p. Clerget engine.


Avro 504M

  In the spring of 1919 Hamble was very busy converting Avro 504Ks for the Avro Transport Company and produced the seven 504Ls, a number of Avro 536 five-seaters and single examples of two dissimilar cabin variants. First of these, built in April of that year, was the Avro 504M, a standard 504K modified above the top longerons to form what was a claustrophobic enclosure accommodating two passengers in staggered seats behind the pilot.
  A curved plywood roof with two glazed portholes in each side was hinged along the port longeron. After it was opened the pilot entered by raising a further section of roofing, and once in, viewed the landscape through five vertical Triplex panels mounted round the edge of the cockpit. A light fabric-covered structure faired the cabin smoothly into the tail and additional side area was compensated by the addition of a 504L-type dorsal fin. Despite the considerable weight penalty, improved streamlining made it faster than the standard 504K.
  The Avro 504M was unusual among British civil Avros in having a 100 hp Gnome Monosoupape nine-cylinder rotary. Application for the temporary registration K-134 was made on May 13, 1919, and, though not officially certificated until June 25, it flew from Hounslow to Margate and back on May 28 and was noted arriving at Southsea Common from Hamble on June 23. The Avro ‘Limousine’ as it was dubbed, made headlines when, on June 26, Lt R. S. Park flew it to Chorley Wood Common, Bucks, to pick up a newly married pair, Mr R. Hamilton and his wife Nora, outside the church. After a refuelling stop at Bournemouth, the 504M landed the honeymoon couple at Fowey, Cornwall, in an elapsed time of four hours. The machine then returned to Hounslow Heath and spent the rest of the summer doing a roaring trade among ladies wishing to fly over London without donning special flying kit. Avro’s manager G. L. P. Henderson made many charter flights in it including return trips to Aintree on July 8 and Brighton on July 13. Its one recorded overseas flight took place in the early hours of September 6 when Capt R. T. Fagan flew nonstop from Hounslow to Le Bourget in 2 hours 45 minutes with Norwegian passengers Robshon and Waase.
  Many hours were flown during the railway strike, by which time the permanent marking G-EACX had been applied but the C of A was not renewed in 1920, no doubt due to the very cramped accommodation of such a primitive conversion. When the Japanese acquired 504K manufacturing rights in 1921, they quickly produced a 504M equivalent known as the Aiba Tsubami IV with 130 hp Gasuden Jimpu engine, one example of which, J-BABC, was still in use in 1928.


SPECIFICATION AND DATA
   Manufacturer: A. V. Roe and Co. Ltd., Hamble Aerodrome, near Southampton, Hants.
   Power Plant: One 100 h.p. Gnome Monosoupape B.2
   Dimensions:
   Span 36 ft. 0 in. Length 29 ft. 5 in.
   Height 10 ft. 5 in. Wing area 330 sq. ft.
   Weights: Tare weight 1,220 lb. All-up weight 1,975 lb.
   Performance:
   Maximum speed 98 m.p.h. Cruising speed 85 m.p.h.
   Climb to 8,000 ft. 5-5 min. Endurance 3 hours
   Production: One aircraft only, K-134/G-EACX, c/n A.T.C.10; sole owner A. V. Roe and Co. Ltd.; C. of A. issued 25.6.19, not renewed in 1920


Avro 504N

  Rapid wartime development of inline vee and radial type engines made possible two parallel 504K postwar modernisation programmes. The first, resulting in the Avro 548 and 552, is described elsewhere, but the front fuselage of the 504K was more suited to the radial and it was an engine of this type which eventually powered the last major variant, the Avro 504N.
  Early in 1919 Avro’s 504K ‘hack’ K-147 flew at Hamble with a 170 hp A.B.C. Wasp I and in the following year D9068 flew at the RAE, Farnborough, with this engine as the so-called ‘fireproof' Avro. The Wasp was chosen in this case as an example of an up-to-date engine to see if the fireproofing scheme, comprising aluminium/asbestos bulkhead, steel-tube engine mounting, external fuel lines and tanks under the lower wing, would be effective for radial engined types of the future. Trials described in R & M 691 began on February 19, 1920, and continued until June 3 when the engine crankshaft failed, delaying further flights until September 28, 1922.
  The Cosmos Engineering Co Ltd also equipped 504K G-EADL at Filton as test-bed for their new 100 hp Lucifer three-cylinder radial (later known as the Bristol Lucifer). Test flying was undertaken by Capt Norman Macmillan but ended abruptly when ’DL broke its back in a difficult forced landing at Kingswood through engine failure in January 1920. The replacement aircraft G-EAJB, on loan from Avro, incorporated the airframe modifications necessary to keep pace with more efficient and powerful engines. The skid-type undercarriage remained, but the famous elastic shock absorbers gave place to a new semi-oleo type in which half the travel was taken by an oil dashpot before picking up rubber-in-compression. Tapered ailerons were also fitted to lighten lateral control and harmonise them with the near-perfect rudder and elevators.
  Early in 1922 the Hamble works fitted G-EADA (one of the old Avro Transport Company 504Ks) with a Bristol Lucifer, and modified two Service machines E9265 and ’66 to take the higher powered 150 hp Armstrong Siddeley Lynx seven-cylinder radial, but all three retained the skid undercarriage. Hinkler flew both Lynx Avros to Croydon for demonstration in May 1922 and ’DA flew in the first King’s Cup Race there on September 8, 1922. Piloted by Maj C. R. Carr it forced landed at Halifax. Although often referred to as the 504N prototypes, they were, more accurately, a first intermediate type. Nor were they the only examples. Years later in 1928 Phillips and Powis Ltd, Woodley, fitted 504K G-EBWO with a 100 hp Anzani radial and tapered ailerons for private owner Dr M. C. Wall and in 1932 Armstrong Siddeley Mongoose engines were installed in 504Ks by Air Travel Ltd, Penhurst. The last example was G-ABVC flown by H. C. Chater with a Lucifer at Lympne in 1935.
  A slightly more advanced interim type was a dual control trainer version with oleo sprung skid-type undercarriage and Lynx engine. Four of these, G-EBHC, ’HD, ’HE and ’HT were supplied to Armstrong Whitworth Ltd in 1923 for use at the A. W. Reserve Flying School at Whitley. In 1931 the survivors, G-EBHD and ’HE, were sold for joyriding to R. O. Roch (Modern Airways Ltd) and L. J. Rimmer (North British Aviation Co Ltd) respectively, the latter being reconverted to Avro 504K (130 hp Clerget).
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Avro 508

  The Avro 508 was a two-seat reconnaissance biplane built at the Manchester works in December 1913 and delivered at Brooklands for erection and test a month later. Following contemporary practice it was a twin boom, three-bay pusher biplane of fabric-covered wooden construction having equal span mainplanes structurally similar to those of the Avro 504 prototype. A wide centre section carried the first pair of interplane struts at its extremities, the dihedral commencing at this point as on the Avro 503. Ailerons were used for lateral control and the machine was noteworthy as the first Avro type to have aileron cables located inside the wing leading-edge and running over buried pulleys.
  A capacious square-section nacelle, built up from four ash longerons and spruce cross-struts, accommodated two crew in tandem. The observer/gunner sat in the nose for maximum field of vision with the pilot behind. Fuel and oil tanks were located behind the pilot’s seat and just ahead of an 80 hp Gnome rotary engine mounted on steel-tube bearers. The use of standard Avro cowlings and centre skid undercarriage heightened its likeness to a back-to-front Avro 504. Tail booms were of steel tubing braced by streamline-section spruce struts, the rear extremities of which were built into the tailplane structure. For ease of dismantling, the booms were jointed just ahead of the tailplane leading-edge. The rudder was an elongated version of the famous comma type, somewhat like an artist’s palette.
  The Avro 508 was not adopted for the Royal Flying Corps and the single machine built made but two public appearances. The airframe was shown without covering at an exhibition at Belle Vue Gardens, Manchester, on January 1-3, 1914, and the complete aircraft was shown on the Avro stand at the Olympia Aero Show, London, on March 16-25, 1914.
  In late April 1915 the Avro 508 was operational at Brooklands, but following the company’s failure to secure orders for the type, it was apparently disposed of to the Hall Flying School at Hendon in whose sheds it was noted in a dismantled state and engineless in April 1916. At that time, the school expressed the intention of fitting dual controls and using the machine for carrying passengers as well as for instruction. Of note is that they expected the Avro 508 to be of particular use during windy conditions when it was adjudged capable of climbing to a height where ‘the wind was steadier than nearer the ground’. However, it is not known if the machine was ever erected at Hendon and pressed into service.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester; and Brooklands Aerodrome, Byfleet, Surrey
   Power Plant: One 80 h.p. Gnome
   Dimensions:
   Span 44 ft. 0 in. Length 26 ft. 9 in.
   Height 10 ft. 0 in. Wing area 468 sq. ft.
   Weights: Tare weight 1,000 lb. All-up weight 1,680 lb.
   Performance: Maximum speed 65 m.p.h. Endurance 4 1/2 hours

Avro 509
  Type number first used for a set of tanks and strut sockets supplied to the Walsh brothers for the first Walsh flying boat, built at Orakei, Auckland, in August 1913. Evidently these components were later considered unworthy of a special type number as the designation Avro 509 was reissued in November 1913 to a projected radio equipped twin-float seaplane. This was a three-seater, three-bay biplane with two 120 hp Austro-Daimler engines outboard and a heavy calibre gun in the nose. A contract, to the value of £3,384, for one prototype was awarded by the Admiralty in January 1914 and serial 94 was allocated. However the machine was not built, possibly because of there being insufficient capital available to finance its construction. Span (upper) 80 ft 0 in, (lower) 56 ft 0 in. Length 44 ft 3 in. Wing area 931 sq ft. Tare weight 2,800 lb. All-up weight 4,510 lb. Maximum speed 70 mph.

Avro 512
  A projected landplane with one 65 hp Austro-Daimler engine. Span 26 ft 0 in.

Avro 513
  A design study made in March 1914 for a two seat, twin-float bomber seaplane powered by two 80 hp Gnome engines. Wings were designed to fold, and floats and flying surfaces were interchangeable with those of the Avro 510. Span (upper) 72 ft 0 in, (lower) 47 ft 0 in. Length 36 ft 6 in.

Avro 515
  Layout for a biplane with one 150 hp Sunbeam engine, September 1914.
Avro 516
  A monoplane with one 80 hp Gnome considered in January 1915.

Avro 517
  Layout for a biplane version of the Avro 516, February 1915

Avro 518
  A projected single-seater with one 150 hp Sunbeam engine, May 1915

Avro 520
  Designs for a single-seat landplane with one 150 hp Sunbeam engine for the Royal Navy, May 1915.

Avro 524
  A projected scout with one 80 hp engine.

Avro 525
  Layout for a single-seat ground attack fighter to RAF Type II; November 1915.
Avro 526
  Similar to the Avro 525 but with monoplane tail unit.

Avro 510

  The Avro 510 was a large two-seat, two-bay seaplane built for the 1914 Circuit of Britain Race. A larger version of the 504 rudder proclaimed the aircraft’s Avro origins but it bore no other resemblance to any previous machine built by the firm. The upper mainplane overhung the lower by more than 12 ft and the extension planes (which carried the ailerons), were braced by cables to steel-tube kingposts. Power was derived from a 150 hp Sunbeam eight cylinder watercooled engine (later named the Nubian), fitted with nose radiator and stub exhausts.
  The undercarriage consisted of four steel struts connected at their lower extremities to a tubular steel rectangle, the corners of which were bolted to the attachment points of each float. These were of entirely new design with a pronounced taper aft of the single step. The tail was supported on a large wooden float with water rudder.
  Built at Manchester in July 1914, the Avro 510 was despatched by rail to Calshot, starting point of the race. Following by road to supervise its erection, A. V. Roe put up for the night at Havant where the next morning he learned of England’s declaration of war on Germany. The race was perforce cancelled but the Avro 510 was erected and flew well, the new float design being particularly successful. Much smoother alightings were possible than with the old flat backed pontoon-type floats.
  When the trials were complete, the machine was purchased by the Admiralty and much to A. V. Roe’s surprise a cheque was handed over on the spot by Capt (later Air Vice Marshal Sir Arthur) Longmore. The Admiralty also placed an order for five production Avro 510s but stipulated a taller undercarriage incorporating an extra inclined strut and using the well-tried, but entirely outmoded, flat backed floats. These were bolted direct to the struts without the complicated sub-frame of the original. To A. V. Roe’s disappointment the modern floats of the prototype were also replaced. RNAS Avro 510s were fitted with a fixed fin having a curved trailing edge which fitted snugly round the leading edge of the rudder. All six were powered by the 150 hp Sunbeam and though data was published for a version with the 160 hp Gnome rotary there is no evidence that this motor was ever fitted to an Avro 510. Delivery of the production machines took place between December 1914 and April 1915 but their performance was very poor and they repeatedly failed to pass acceptance tests. Only solo flying proved possible. This resulted in all but 130 being sent to the Supermarine Works at Woolston for modification in October 1915. All the machines had been removed from the active list by March 1916.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester
   Power Plants:
   One 150 h.p. Sunbeam Nubian
   Dimensions:
   Span (upper) 63 ft. 0 in. (lower) 38 ft. 0 in.
   Length 38 ft. 0 in.
   Wing area 564 sq. ft.
   Weights:
   Tare weight 2,080 lb. All-up weight 2,800 lb.
   Performance:
   Maximum speed 70 m.p.h.
   Climb to 1,000 ft. 4 1/2 minutes. Endurance 4 1/2 hours
   Production:
   Prototype sold to the Admiralty 1914 and numbered 881
   Production machines built under Contract C.P.30654/14:
130 - delivered to RNAS Killingholme 6.12.14, to Grain 10.4.15, fitted with non-standard undercarriage and floats in mid-1915.
131 - delivered to Killingholme 5.2.15, acceptance test flights by F. P. Raynham 15.4.15, dismantled 18.10.15, to Woolston by sea 21.10.15.
132 - delivered to Killingholme 17.2.15, erected 3.15, acceptance test flights by F. P. Raynham 15.4.15, dismantled 18.10.15, to Woolston by sea 21.10.15
133 - delivered to Dundee, erected 25.3.15, preliminary trials flown 31.3.15, declared to be ‘of negligible value’ 3.9.15, to Woolston 26.10.15
134 - delivered to Dundee 4.4.15, acceptance test flights flown on 12.4.15, used for a few operational patrols without observer, order given to return machine to its makers 19.10.15

Avro 511

  Three full-sized aircraft shown on the Avro stand at the Olympia Aero Show, London, March 16-25, 1914, were a production Avro 504 seaplane, the Avro 508 pusher and the Avro 511 single-seat, single-bay biplane. This was designed specifically for fast scouting in the event of war and could be swiftly dismantled for road transport to the operational area. Heavily staggered, sparless mainplanes of cellular construction, designed and stressed by Avro’s assistant designer H. E. Broadsmith, were given pronounced sweepback in an attempt to reduce the span and attain inherent stability. On this account the aircraft was promptly and unofficially dubbed ‘Arrowplane’ or even ‘Arrowscout’ by the sensational press but these names can find no place in a serious work of reference. Ailerons were fitted to all four wings and single wide-chord interplane struts were used on each side. Landing flaps were incorporated in the inboard trailing edges of the lower mainplanes and pivoted diagonally about a stout steel tube which passed through the fuselage. This device, years ahead of its time, reduced touchdown speed to 35 mph.
  The Avro 511 was otherwise typically Avro with standard centre-skid undercarriage and comma-type rudder. The nose was of good streamline shape with a close fitting cowling round the 80 hp Gnome Monosoupape rotary engine. The cowling was later modified as it prevented adequate cooling. Estimated maximum speed was 95-100 mph and the machine was to have been piloted by F. P. Raynham in the Aerial Derby Race round London on May 23, 1914 (racing No. 14). Storms on the eve of the race caused deterioration in the weather which led to a postponement until June 6 but Raynham managed to make one or two demonstration runs for the benefit of the few hardy spectators. When returning home on the following day he made a safe landing after the engine failed within gliding distance of Brooklands. It had not proved as fast as had been hoped but was nevertheless entered (racing No.20) in the postponed Aerial Derby.
  In preparation for this event the Avro 511 was fitted with alternative mainplanes without sweepback which Broadsmith had designed in case trouble was encountered with the swept wings. The rebuilt machine, designated Avro 514, was also equipped with a light weight, unsprung, V-type racing undercarriage without the familiar skid, but while taxying out at Brooklands to take off for Hendon on the eve of the race, an eye bolt sheared. The undercarriage collapsed, breaking the airscrew and bending the engine crankshaft as well as damaging wings and fuselage. After reconstruction at Manchester the Avro 514 was successfully flown from Southport Sands by F. P. Raynham in July 1914 but further development was ended by the outbreak of war.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester; and Brooklands Aerodrome, Byfleet, Surrey
   Power Plant: One 80 h.p. Gnome Monosoupape
   Dimensions:
   Span 26 ft. 0 in. Length 22 ft. 4 in.
   Height 9 ft. 4 in. Wing area 235 sq. ft.
   Weights: Tare weight 675 lb. All-up weight 1,165 lb.
   Performance: Maximum speed 95-100 m.p.h.

Avro 521

  Designed late in 1915, the Avro 521 two-seat fighter-trainer was a hybrid embodying the features of several Avro 504 variants. In side elevation the straight top longerons proclaimed it a derivative of the 504 prototype, yet the short-span ailerons and the rudder-tail skid assembly were pure 504A, the cockpit positioning and centre-section struts were 504E, the V-strut undercarriage was contributed by the 504G and the streamlined headrest was copied from the Avro 519. Standard Avro 504 mainplanes were shortened to a span of 30 ft, cut away at all four wing roots to improve upward and downward vision and rigged with only a single set of interplane struts on each side. The engine was a 110 hp Clerget rotary in characteristic Avro cowlings.
  The initial order was for one machine, test flown at Trafford Park, Manchester, by F. P. Raynham with H. E. Broadsmith standing up in the rear cockpit and brandishing a dummy machine-gun to enable the effect of the extra drag to be assessed. Raynham found the Avro 521 longitudinally unstable and unpleasant to fly; nevertheless it was delivered to Farnborough in February 1916 and 25 production machines were ordered for the RFC.
  Proposals were also made for interchangeable wings to suit different roles. Designation Avro 521A was allotted to a version with three-bay mainplanes of 42 ft span. At least one Avro 521A was built but it is thought that the Avro 521B, intended to have standard Avro 504 wings of 36 ft span, remained on the drawing board. Construction of the production batch, it is believed, was suspended due to the type’s instability and that only one or two machines were completed. None was delivered to the RFC.
  One Avro 521, most probably the prototype, was however at the Central Flying School, Upavon, in the summer of 1916 where it was flown amongst others by Lt H. H. Balfour (later Lord Balfour of Inchrye, PC, MC). The machine was considered ‘a beast to fly’ and its tendency to spin off a righthand turn eventually claimed the life of Lt W. H. Stuart Garnett, a scientist pilot with the CFS Testing Flight, who spun in from 1,500 ft on September 21, 1916.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester
   Power Plant: One 110 h.p. Clerget
   Production: One unmarked prototype Works Order number believed 1811; and twenty-five production aircraft 7520 to 7544, believed not all built
   Service Use: At the Advanced Training School, Gosport, Hants.

Avro Type 519

  Evolved from the Avro 510 seaplane and built for the Admiralty early in 1916, the Avro 519 was a single-seat biplane bomber with folding wings, a scaled-up version of the standard Avro central skid undercarriage and a large fin and rudder of the style used on the Avro 504B.
  In addition to the two Avro 519s built for the RNAS a pair of two-seat Avro 519As with stout V-strut undercarriage and having no central skid were ordered for the RFC. All four machines had unique characteristics. The first Type 519, 8440, which spent some time at Eastchurch in 1916, was fitted with side-mounted radiators. Sister machine 8441 and the first of the two 225 hp Sunbeam powered aircraft for the RFC, 1614, were fitted with a large radiator mounted above and behind the engine. This unit not only blocked the pilot’s forward view but would also have introduced high additional drag to a type known for its poor rate of climb. It is thought that it was in an attempt to correct this lack of performance that the second RFC machine, 1615, was completed with equal-span wings approximately 43 ft in length. This machine was a Type 522, a fact confirmed by sign-writing on the side of its fuselage, but despite this it was still officially referred to as a Type 519A.
  This last machine, 1615, was despatched to Hamble from Manchester on November 1, 1916, and though ready for military acceptance by December 8, 1916, remained there until April 1917 when it departed along with 1614 and 8441 which were also at Hamble at that time. The fact that company reports talk of ‘managing to get rid’ of these three machines is a measure of their success.
  Photographs taken by test pilot Capt F. T. Courtney suggest that all four machines were tested at Farnborough where they were dubbed ‘The Big Avros’. 1614 was there in May 1916. Their ultimate fate is unknown.


SPECIFICATION AND DATA

Manufacturers:
   A. V. Roe and Co Ltd, Park Works, Newton Heath, Manchester; and Hamble Aerodrome, near Southampton, Hants.
Powerplants:
   One 150 hp Sunbeam Nubian
   One 225 hp Sunbeam

Dimensions:
Avro 519 Avro 519A Avro 522
Span (upper) 63 ft 0 in 63 ft 0 in 43 ft 0 in
Span (lower) 38 ft 0 in 38 ft 0 in 43 ft 0 in
Length (150 hp Sunbeam) 32 ft 9 in - -
33 ft 3 in - -
Length (225 hp Sunbeam) 35 ft 1 3/4 in 33 ft 10 in 33 ft 8 in
Height 11 ft 8 in* 11 ft 8 in* -
Wing Area 600 sq ft 600 sq ft -
*measured to the highest point on the upper surface of the wing

Weights:
   (Avro 519) All-up weight 3,000 lb
Performance:
   (Avro 519) Speed 75 mph Climb 6,000 ft in 30 mins
Production:
   (Type 519 for RNAS) 8440 and 8441
   (Type 519A for RFC) 1614
   (Type 522 for RFC) 1615

Avro 523 Pike

  In 1916 A. V. Roe decided to move the Avro factory from Manchester to a waterside site convenient for the development of naval aircraft, and bought the stretch of Hampshire grassland which is now Hamble Aerodrome, together with a mile of foreshore on the adjacent Southampton Water. Manchester architect Harry Fairhurst designed the new Avro Hamble Works and a garden city of 350 houses for employees, but after the hangars and only 24 houses had been built, wartime shortage of building materials halted the scheme. Very reluctantly the company was compelled to keep its main works in Manchester and to use Hamble only for erection and as an experimental establishment.
  It was to Hamble therefore that their first twin-engined machine and the first to receive a type name, the Avro 523 Pike, was sent for erection and test. Designed by Roy Chadwick to RAF Types IV, VI and VII as a long-distance photo-reconnaissance fighter or short range day or night bomber, it was powered by two opposite-handed 160 hp Sunbeam engines driving pusher airscrews. A fine example of advanced thinking, the Pike was a large three-bay biplane equipped with horizontal-tier bomb-stowage (designed personally by A. V. Roe) and carrying the pilot just ahead of the mainplanes. Gunners’ cockpits fore and aft were armed with Lewis guns on rotatable ring mountings. The divided undercarriage was sprung with larger editions of the famous Avro shock absorbers, and a large comma-type rudder was hinged to a fixed fin of low aspect ratio.
  Although the Pike was apparently sent to Hamble some months earlier, the aircraft was erected over a twelve-day period ending on November 11, 1916. After initial tests, new wings were called for by the Admiralty and these arrived at Hamble on January 22, 1917. Performance on a mere 320 hp was said to be very good but the Pike appeared too late. Production contracts had already been awarded to Short Bros for a standard RNAS bomber, and the RFC was interested solely in the much larger Handley Page heavy bombers then under construction.
  During test flying, the Pike was sent to the RNAS experimental establishment on the Isle of Grain for demonstration before Admiralty officials but during one flight the Pike was flown with the C.G. position too far aft and was so tail heavy that F. P. Raynham dared not throttle back to attempt a landing. The situation was saved through the gallantry of R. H. Dobson (later Sir Roy Dobson), who climbed out of the rear cockpit and along the top of the fuselage to transfer his weight to the bow gunner’s position. The danger of stalling was averted and a successful landing made. By the end of February 1917, the Pike was ready for delivery, though it was not actually flown to Eastchurch until March 24, 1917.
  A second machine, the Avro 523A, built at Manchester and initially tested at Southport, was fitted with two 150 hp Green engines like its predecessor driving pusher airscrews and cooled by nose radiators on each nacelle. Available photographs suggest it was flown both with a single fin and triple fin arrangement. The latter had two Avro 504 style comma rudders outboard which was possibly an attempt to overcome reported stability problems. On completion of four weeks of extensive test flying the machine, which was allocated the RFC serial A316, was despatched from Southport to Hamble on September 11, 1916. Its exposure to the elements at Southport necessitated thorough renovation during which process it was converted to tractor configuration with revised engine mounts and rear radiators and the two outboard fins were dispensed with. It flew for the first time in this form in February 1917. Later, after the completion of official tests both machines were returned to the manufacturers to enjoy extensive experimental careers and were still in commission at Hamble in 1918. Plans to produce Avro 523B and 523C variants with higher powered Sunbeam and Rolls-Royce engines were shelved, but the Admiralty ordered an improved version which appeared in 1917 as the Avro 529.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester; and Hamble Aerodrome, near Southampton, Hants.
   Power Plants:
   (Avro 523) Two 160 h.p. Sunbeam
   (Avro 523A) Two 150 h.p. Green
   Dimensions:
   Span 60 ft. 0 in. Length 39 ft. 1 in.
   Height 11 ft. 8 in. Wing area 815 sq. ft.
   Weights: (Avro 523) Tare weight 4,000 lb. All-up weight 6,064 lb.
   Performance: (Avro 523)
   Maximum speed 97 m.p.h.
   Climb to 5,000 ft. 9 min. 30 sec.
   Endurance 7 hours
   Production:
   (Avro 523) One aircraft only, Works Order number believed to be 2230. Allocated the serial N523 after delivery to the RNAS.
   (Avro 523A) Two aircraft ordered to contract 87/A/329 dated April 12, 1916, and serials A316 and A317 allocated. It is believed that only A316 was built and that its Works Order was 2231.



Avro 529

  In 1916 the Admiralty ordered two enlarged versions of the Pike for long-range bombing duties. Unnamed and known only as the Avro 529 and 529A, they had three-bay folding wings rigged without dihedral, and although closely resembling the Pike were distinguishable from it by the rudder shape. That of the Pike was flat topped with a straight bottom edge to the balance portion, but those of the Avro 529s were curved with a semicircular balance area.
  Whereas the first aircraft was built wholly in Manchester and assembled at Hamble, the second was sent there in unfinished state to make way for increased Avro 504K production at Manchester. The Avro 529, first flown in March 1917, was powered by uncowled 190 hp Rolls-Royce Falcons mounted at mid-gap and driving opposite handed airscrews. The Avro 529A, flown at Hamble in the following October, had two 230 hp Galloway-built B.H.P. engines which were fully cowled and housed in nacelles on the lower mainplane. Radically different installations called for two distinct types of fuel systems and in the Avro 529 petrol was carried in a 140 gallon tank in the centre fuselage. On the Avro 529A each nacelle carried its own 50 gallon supply with small wind-driven pumps to raise the fuel to a 10 gallon gravity tank above the engine.
  Lewis guns were mounted on Scarff rings over front and rear cockpits and the rear gunner was provided with emergency dual control. The front gunner also acted as bomb aimer and steered the pilot on to target with the aid of a Gosport speaking tube. On the 529A, which carried twenty 50 lb bombs stowed nose upwards inside the fuselage between the spars of the lower wing, he was able to use a projecting prone position in the cockpit floor.
  Apart from poor elevator control (a shortcoming of both types), the performance of the Avro 529A was very good on such low power, asymmetrical flying being particularly easy. Nevertheless no production contract materialised and only the prototypes were built.
  Both machines were tested at the Aeroplane Experimental Station, Martlesham Heath. The Avro 529A 3695 arrived there for its trials on October 31, 1917, but during the course of these the rudder gave way in the air on November 11, 1917, and the machine crashed. Interestingly, the same problem had occurred, without catastrophe, to the Avro 529 during initial tests in March 1917 and the rudder was strengthened as a result. This first machine was last heard of on January 19, 1918, when it was flown in comparative trials at Martlesham with the Blackburn Kangaroo prototype B9970, a machine which was both larger and more powerful than the Avro 529.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester; and Hamble Aerodrome, near Southampton, Hants.
   Power Plants:
   (Avro 529) Two 190 h.p. Rolls-Royce Falcon
   (Avro 529A) Two 230 h.p. B.H.P. (Galloway-built)

Dimensions, Weights and Performances:
   Avro 529 Avro 529A
Span 63 ft. 0 in. 64 ft. 1 in.
Length 39 ft. 8 in. 39 ft. 8 in.
Height 13 ft. 0 in. 13 ft. 0 in.
Wing area 922 1/2 sq. ft. 910 sq. ft.
Tare weight 4,736 lb. 4,361 lb.
All-up weight 6,309 lb. 7,135 lb.
Maximum speed 95 m.p.h. 116 m.p.h.
Climb
   to 5,000 ft. - 7 min. 0 sec.
   to 6,500 ft. 11 min. 25 sec. 9 min 50 sec
Ceiling 13,500 ft. 17,500 ft.
Endurance 5 hours 5 hours 15 min.

   Production: Prototypes only under Contract CP. 122495/16 with R.F.C. serials 3694 (Avro 529) and 3695 (Avro 529A)

Avro 530

  The Avro 530, first flown in July 1917, was a two-seat fighter which failed to secure a production contract in the face of competition from the celebrated Bristol Fighter because of non-availability of engines. The 300 hp water-cooled Hispano-Suiza was not obtainable when required and the machine flew with a 200 hp Hispano-Suiza. Even on the lower power the performance of the Avro 530 rivalled that of the Bristol and it might still have become one of the famous fighters of the First World War had not almost all 200 hp Hispano-Suiza engines been reserved for the S.E.5A.
  Built at Manchester and erected and flown at Hamble, the Avro 530 was an unusually clean two-bay biplane. Its deep fuselage was of wire-braced, box-girder construction with the fabric covering stretched over formers to give a more streamlined shape. The engine mounting consisted of strutted duralumin girders. The pilot occupied the front cockpit with a single Vickers gun mounted in a large plywood fairing on top of the fuselage ahead of him. This fairing obstructed the pilot’s forward view and the machine was later rebuilt with new top decking and much smaller fairing. In this form the top wing was on a level with the pilot’s eyes, ensuring adequate view in all upward and forward directions while a rear gunner armed with a single Lewis gun on a Scarff mounting commanded the downward and rearward view.
  The fabric-covered, wooden mainplanes were of RAF 14 section and engine cooling was by a large frontal radiator. Though the aircraft was initially flown without it, the lines of the short, blunt nose were later improved by fitting a hollow, open-fronted metal spinner. The famous Avro skid-type undercarriage gave place to a new unit comprising two narrow Vs, braced by an internal V-strut, later faired with metal sheeting to reduce drag. Landing speed was reduced by trailing-edge flaps actuated by a handwheel in the pilot’s cockpit. They were fitted to both upper and lower mainplanes between the inboard ends of the ailerons and the fuselage. Trials proved that the original small fin and rudder were inadequate and a number of different tail units were tested before the final balanced rudder arrangement was adopted.
  In an attempt to solve the engine supply problem, the second prototype Avro 530 was completed with a 200 hp Sunbeam Arab engine. An unfaired, wide angle V undercarriage was fitted; there was no spinner; the tail fin was larger and more gracefully curved; and new RAF 15 section mainplanes were fitted. These were without flaps but had long-span ailerons and metal cuffs to fair the ends of the interplane struts into the wing.
In view of its deep and capacious fuselage, the Avro 530 was offered in 1920 as a high-speed touring aeroplane with comfortable tandem cockpits above a large baggage compartment. There is no evidence that this modification took place and the machine did not receive a civil registration.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester; and Hamble Aerodrome, near Southampton, Hants.
   Power Plants
   One 200 h.p. Hispano-Suiza (first prototype)
   One 200 h.p. Sunbeam Arab (second prototype)
   Dimensions:
   Span 36 ft. 0 in. Length 28 ft. 6 in.
   Height 9 ft. 7 in. Wing area 325 1/2 sq. ft.
   Weights:
   Tare weight 1,695 lb. (1,760 lb.)
   All-up weight 2,680 lb. (2,500 lb.)
   Performance:
   Maximum speed 114 m.p.h. (118 m.p.h.)
   Cruising speed 95 m.p.h. (102 m.p.h.)
   Climb to 5,000 ft. 6 min. 30 sec. (5 min. 30 sec.)
   Ceiling 18,000 ft. Endurance 4 hours
   Production:
   Two prototypes only; Contract A.S.425/17 let on 15.5.17 and serials B3952 and B3953 were allocated. Two further serials, B9431 and B9432, were allocated against the same contract on 26.7.17. As no identity appeared on either machine, which if any serials were actually used is not known.

   Note - Estimated figures for proposed civil version in parentheses.

Avro 533 Manchester

  The Manchester of 1918, final variation on the Pike/Avro 529 theme, was a three-seat, twin-engined bomber or photographic reconnaissance fighter designed to Air Ministry requirements round two of the new 320 hp A.B.C. Dragonfly I seven-cylinder radial engines. Unlike its forebears the Manchester was constructed entirely at Hamble and its deeper, more shapely fuselage giving improved crew accommodation was but one of many refinements, others including a graceful (almost de Havilland-shaped) rudder, and ailerons balanced by means of ‘park bench’ auxiliary aerofoils.
  Erection of the first Manchester was completed by October 1918 after which it was dismantled for covering, during which the opportunity was taken to fit two 300 hp Siddeley Puma high-compression, water-cooled engines. This was to prevent interruption of flight tests by the non-delivery of the Dragonfly engines which had run into a number of teething troubles. The Pumas arrived at Hamble in November, and thus powered, the aircraft was known as the Avro 533A Manchester Mk.II. First flights took place early in December 1918 and the Mk.II aircraft F3492 consequently had an earlier serial than the Mk.I which followed. On December 20 F3492 went to No.186 Development Squadron, Gosport, where it remained until at least January 9, 1919, before proceeding to Martlesham in the following March. Official trials lasted until September 1919 when F3492 returned to Hamble to be fitted with Napier Lions, a project which did not materialise.
  Delivery of the Dragonfly engines in December 1918 enabled the second airframe, F3493, to be completed as the Manchester Mk.I. After prolonged manufacturer’s tests it was flown from Hamble to Martlesham for official trials in October 1919, the journey via Winchester, Basingstoke, London and Chelmsford occupying 90 minutes.
  Apart from the engines and the revised nacelle shape of the Mk.I which decreased the effective area of the lower wing by 4 sq ft, the two marks ofManchester differed only in their tail units. Both had balanced rudders but all tail surface areas were greater in the Mk.I which had taller vertical surfaces and an unbalanced elevator. That of the Mk.II was horn-balanced.
  The performance of both marks was quite remarkable on comparatively low power and despite their size could be looped and spun, but the need for a bomber of this type disappeared when the war ended. A third airframe, intended as the Manchester III with two 400 hp Liberty engines, was completed but the engines were never fitted. The jigs were then dismantled and A. V. Roe’s war effort was at an end.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Hamble Aerodrome, near Southampton, Hants.
   Power Plants:
   (Mk. I) Two 320 h.p. A.B.C. Dragonfly I
   (Mk. II) Two 300 h.p. Siddeley Puma high compression
   (Mk. III) Two 400 h.p. Liberty 12
   Dimensions:
   Span 60 ft. 0 in. Length 37 ft. 0 in. Height 12 ft. 6 in.
   Wing area (Mk. I) 813 sq. ft. (Mk. II) 817 sq. ft.
   Weights:
   (Mk. I) Tare weight 4,887 lb. All-up weight 7,390 lb.
   (Mk. II) Tare weight 4,574 lb. All-up weight 7,158 lb.
   Performance:
   (Mk. I) Maximum speed 112 m.p.h.
   Climb to 10,000 ft. 14 min. 20 sec.
   Ceiling 19,000 ft. Endurance 5 3/4 hours
   (Mk. II) Maximum speed 119 m.p.h.
   Climb to 10,000 ft. 16 min. 30 sec.
   Ceiling 17,000 ft. Endurance 3 3/4 hours
   Production:
   F3492 (Manchester Mk. II);
   F3493 (Manchester Mk. I);
   F3494 (Manchester Mk. III) airframe only

Avro 531 Spider

  First flown at Hamble in April 1918, the Spider was an unsponsored private venture single-seat fighter in which many Avro 504K components were used for speed of manufacture. To this end a shortened rear fuselage of conventional construction with spruce longerons was married to a standard Avro 504K front fuselage and the engine was a ‘borrowed’ 110 hp Le Rhone. There seems little doubt that the Avro company hoped that the Spider would replace the single-seat Avro 504K night fighter in the Home Defence Squadrons. To simplify rigging (a time consuming operation not acceptable to squadrons in the field) all flying and landing wires were replaced by very rigid welded steel Warren girder interplane bracing. This comprised six faired steel tubes arranged in three inverted triangles on each side, anchored to the main spars of the upper mainplane and to the front spar of the lower. Ailerons were fitted only to the upper wing, the lower being shorter and with a chord of only 2 ft 6 in.
  The simple steel V-strut undercarriage was reminiscent of the second Avro 530 and the attempt made in the earlier design to improve substantially the pilot’s field of vision was carried a stage further in the Spider by siting the cockpit under a circular aperture in the centre section. This was mounted close to the fuselage so that the pilot’s head protruded above it. Armament consisted of a single synchronised Vickers gun on top of the fuselage and slightly to starboard of centre.
  The little fighter was a delight to handle, with powerful and well harmonised controls which made it extremely manoeuvrable, and more than a match for many of its contemporaries. Performance was further enhanced by fitting a 130 hp Clerget and drawings were made for the installation of a 150 hp Bentley B.R.l rotary or a 170 hp A.B.C. Wasp I radial. Well-known pilots were invited to fly it in off duty hours and to give their opinions, for which purpose it was at the School of Special Flying, Gosport, from April 27 to May 18, 1918, and again on July 13. In this way the Spider became such a topic of conversation that the Air Ministry could not fail to take note of it. Nevertheless it was not ordered into production because the Sopwith Snipe had already been standardised as the RAF’s next single-seat fighter. The Spider was therefore used for experimental work which included benzole fuel tests at Alexandra Park in August, 1919.
  A considerably modified version of the Spider was allotted type number Avro 531A. This had conventional two-bay, wire-braced mainplanes rigged with a considerable stagger and using 504K-type interplane struts. With the 130 hp Clerget rotary the Avro 531A had a performance similar to that of the Spider. While a Type 531A was reported to be under construction in early 1919, there is no means of proving that it ever existed as such and it is probable that the machine donated its fuselage, undercarriage and tail unit to the civil Avro 538, and first flew in this form.
  The Avro 538 emerged from the flight shed at Alexandra Park, Manchester, in May 1919 registered K-132, a temporary civil marking later changed to G-EACR. As far as is known these letters were never carried and the machine’s main adornment was the word AVRO in the usual enormous black letters. Although powered by a 150 hp Bentley B.R.l and intended as a racer, a main spar defect limited the machine’s activities to straight and level flight, and a notice to this effect was displayed in the cockpit. Bearing fleet number 7, the Avro 538 was used solely by the Avro Transport Company’s chief engineer J. C. C. Taylor, who flew it around the joyriding sites in order to sign out the Avro 504Ks.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Clifton Street, Miles Platting, Manchester; and Hamble Aerodrome, near Southampton, Hants.
   Power Plants:
   (Avro 531)
   One 110 h.p. Le Rhone
   One 130 h.p. Clerget
   (Avro 531A) One 130 h.p. Clerget
   (Avro 538) One 150 h.p. Bentley B.R.I

Dimensions, Weights and Performances:
   Avro 531 Spider Avro 531A Avro 538
   Clerget *Bentley Clerget Bentley
Span (upper) 28 ft. 6 in. 28 ft. 6 in. 28 ft. 0 in. 28 ft. 0 in.
Span (lower) 21 ft. 6 in. 21 ft. 6 in. 27 ft. 0 in. 28 ft. 0 in.
Length 20 ft. 6 in. 20 ft. 6 in. 20 ft. 6 in. 20 ft. 6 in.
Height 7 ft. 10 in. 7 ft. 10 in. 8 ft. 6 in. 8 ft. 6 in.
Wing area 189 sq. ft. 189 sq. ft. - 210 sq. ft.
Tare weight 963 lb. 1,148 lb. 960 lb. 975 lb.
All-up weight 1,517 lb. 1,734 1b. 1,514 1b. 1,400 1b.
Maximum speed 120 m.p.h. 124 m.p.h. 120 m.p.h. 125 m.p.h.**
Climb
   to 3,500 ft. - 2 min. 12 sec. - -
   to 5,000 ft. 4 min. 0 sec. - 4 min. 0 sec. 4 min. 0 sec.
   to 10,000 ft. - - - 10 min. 0 sec.
Ceiling 19,000 ft. - 19,000 ft. -
Endurance/Range - 2 1/2 hours 3 hours 320 miles
*Estimated figures. **Cruising speed 108 m.p.h.

Production:
   (Avro 531) One prototype only;
   (Avro 538) One aircraft only, K-132/G-EACR, c/n 538/1, registered to A. V. Roe and Co. Ltd. 25.5.19, s.o.r.* 9.20
*Abbreviation used throughout to indicate 'struck off register'.

Avro 536

  Reference has been made in previous chapters to a unique batch of civil aircraft built in the Hamble works between April and November 1919. To satisfy the enormous demand for pleasure flights, the Avro Transport Company simply had to provide more seats and quickly. The problem was solved by giving some of these Hamble 504K variants a nine-inch increase in width to enable four passengers to sit in side by side pairs in the rear cockpit. Each occupant had his own individual windscreen, the rear windscreens being fixed to a strip of decking hinged to the starboard top longeron for ease of entry. In this form, as the Avro 536, the machine was a short-range five-seater and (as in the case of Avro 504Ls from the same production batch), extra take-off power at the higher all-up weight was given by a 150 hp Bentley B.R.l.
  The Avro 536 was easily distinguishable from the 504K since the extra nine inches of width resulted in an obvious difference in the spacing of the centre section struts. Having a tricolour rudder, but no other markings apart from AVRO in large white letters, the prototype first flew at Hamble in April 1919, one of the first passengers being the Lord Chancellor who flew in it with H. A Hamersley on the 25th of that month. Seven production 536s which followed plunged immediately into the fray at southern joyriding sites: K-104 and K-105 at Hounslow Heath; K-116 and K-137 at Southsea; K-161 at Weston-super-Mare; and K-166 at Margate. K-165 is believed to be that sent to the First Air Traffic Exhibition at Amsterdam. A batch of 12 was also put in hand at Manchester but only seven of these were certificated in time to earn money in 1919. Whereas the constructor’s numbers of the Hamble batch were prefixed A.T.C. (Avro Transport Company), those built in Manchester were initialled B for Blackpool where three pilots carried 500 passengers in 536s on the day of their introduction.
  All Avro 536s had the 504L-type fin to offset the torque of the powerful Bentley rotary except the first three production aircraft, two of which were involved in serious accidents. Capt H. R. Hastings was killed when K-105 stalled on approaching Sandhurst at the end of a charter flight from Hounslow on August 6, 1919; and Capt E. A. Sullock, on direct track from Hounslow to Southend with two passengers on September 9, suffered engine failure over Rotherhithe and put K-104 down in Southwark Park where it broke its back. A third Avro pilot, Brig-Gen C. F. Lee CMG, who had demonstrated the 504J C4312 at Washington in 1917, was killed when the fin-equipped K-161 stalled when coming in to land on Weston-super-Mare sands in the same month.
  Unlike other Avro 536s, the prototype boasted a large aerofoil-shaped centre-section fuel tank and after a few trial flights at Hamble, was fitted with floats and extended fin to become the sole 536 seaplane. It retained the tri-colour rudder and on July 2, 1919, began a joyriding season in the Isle of Wight as K-114. The pilot was Capt F. Warren Merriam who flew A. V. Roe daily to and from Hamble while he was on holiday in the island and, assisted by a 504L, completed a two months’ lucrative season at Ryde, Sandown, Shanklin and Ventnor. The last two Hamble-built 536s were special aircraft; K-139/G-EADV was a two-seater with large fuselage fuel tank for experimental work or long-distance competition flying, and the other (23rd and last machine on the mixed production line) was converted into a cabin type known as the Avro 546 for three passengers and pilot. Main differences between this aircraft and the contemporary Avro 504M lay in the widened fuselage, open pilot’s cockpit, squarish windows below the top longeron and the Bentley B.R.1 engine. Registered G-EAOM, the Avro 546 saw little service and only made a few flights at Hamble and West Blatchington Farm, Brighton, early in 1919-20.
  When the Avro Transport Company ceased operations a few of its former pilots hired 536s and carried on in 1920 but all eventually returned to Alexandra Park for storage. Four from the tail end of the production line (G-EAKM-’KP), completed too late to be used commercially, were also stored. In 1923 F. J. V. Holmes bought ’KN for use by Berkshire Aviation Tours Ltd and in 1925 ’KJ, ’KM and ’KP were acquired by Surrey Flying Services Ltd to take over joyriding from their aged 504Ks.
  Bentley rotaries were no longer in service in 1925 and the Surrey Avro 536s were fitted with Clergets. With reduced fuel loads they were very economical indeed, carrying pilot and four passengers quite satisfactorily on the company’s famous 5 minute/5 shilling ‘flips’. Low power also made the dorsal fin unnecessary and in 1926-27 the firm erected four additional Avro 536s G-EBOF, ’OY, ’RB and ’TF, for which no original construction details were recorded. They were evidently the best of the airframes still remaining in store and the unexplained constructor’s number P.8 given for G-EBOY is believed to be a corruption of B.8, identifying it as the former G-EAKL. They seldom ventured far afield, although G-EBOY gave joy flights from the beach at Jersey in 1927 and during a barnstorming tour in 1928 ’RB was used extensively for wing walking exhibitions.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Co. Ltd., Newton Heath, Manchester; and Hamble Aerodrome, near Southampton, Hants.
   Power Plants:
   (Avro 536)
   One 130 h.p. Clerget
   One 150 h.p. Bentley B.R.I
   (Avro 546)
   One 150 h.p. Bentley B.R.I
   Dimensions:
   Span 36 ft. 9 in.
   Length 29 ft. 5 in.
   Height 10 ft. 5 in.
   Wing area 335 sq. ft.
   Weights:
   Tare weight 1,431 lb.
   All-up weight 2,226 lb.
   Performance:
   Maximum speed 90 m.p.h.
   Cruising speed 70 m.p.h.
   Initial climb 550 ft./min.
   Ceiling 12,000 ft. Range 190 miles
Note: The above figures apply to both Avro 536 and 546.

Avro 539

  Rushed through the Hamble works in time for the 1919 Schneider Trophy Race, the Avro 539 single-seat twin-float seaplane was the smallest biplane that could be designed round the 240 hp Siddeley Puma engine. Its wooden structure was typically Avro but there was little external resemblance to any of the company’s previous aeroplanes. The fuselage was a rectangular-section box-girder with deep curved fairings above and below to conform to the lines of the engine cowlings. These were a close fit with the cylinder heads projecting through them and cooling was by nose radiator.
  Single-bay mainplanes with rounded tips were rigged with dihedral on the lower, shorter plane only. The tailplane was of generous area and an unbalanced rudder was hinged to a considerable dorsal fin. Four streamlined steel tubes carried two 14 ft single-step wooden floats at a track of 7 ft but there were no wingtip or tail floats. Piloted by Capt H. A. Hamersley, the Avro 539 first flew from Hamble slipway on August 29, 1919, but apart from the national G outlined in white on the rudder, no marks were carried despite the allocation of registration G-EALG eight days before. When taking off for eliminating trials at Cowes on September 3, a float was damaged by floating debris and a separate trial was arranged for September 8. This allowed time not only for repairs but for the fitment of a horn-balanced rudder, a change of fin shape and the display of full registration marks under the revised designation Avro 539A. The Schneider contest took place at Bournemouth on September 10, with the Avro 539A acting as reserve British machine to the Sopwith Schneider and the Supermarine Sea Lion I. These were to compete with French and Italian entries but the race was declared void because of fog.
  Deprived of an opportunity of showing its paces, the aircraft returned to Hamble where it was eventually converted into a landplane for the Aerial Derby at Hendon on July 24, 1920. A rigid V undercarriage was located well forward as on early Avro Babies, the fin area was reduced, and a small streamlined headrest fitted. Still known as the Avro 539A, G-EALG was flown in the race by Capt D. G. Westgarth-Heslam who forced landed drenched in fuel at Abridge, Essex.
  The unlucky racer then returned to Hamble for a more extensive reconstruction to permit the installation of a 450 hp Napier Lion driving a 10 ft diameter Avro airscrew. By removing the frontal radiator it was possible to rebuild the nose with a downward slope to improve both streamlining and forward view. The three banks of cylinders projected from smoothly tapering cowlings which terminated in a conical airscrew boss, the engine being cooled by small radiator units on each side of the fuselage ahead of the cockpit. With an engine almost twice the power and weight of the original, it was necessary to shorten the nose and to strengthen the fuselage by planking it with plywood. A more robust undercarriage with rubber-in-compression shock absorbers was also necessary.
  In this form the machine was re-registered G-EAXM under the designation Avro 539B and first flew at Hamble piloted by D. G. Westgarth-Heslam on July 13, three days before the 1921 Aerial Derby Race in which it was entered. At the end of this, its only flight, he made a perfect landing too far up the aerodrome and overshot into a railway cutting leading to the old RAF Assembly Park. The 539B was completely wrecked and the pilot was seriously injured.
  
SPECIFICATION AND DATA
Manufacturers:
A. V. Roe and Co Ltd, Hamble Aerodrome, near Southampton, Hants.
Powerplants:
(Avro 539) One 240 hp Siddeley Puma
(Avro 539A) One 240 hp Siddeley Puma
(Avro 539B) One 450 hp Napier Lion
Dimensions:
Span (upper) 25 ft 6 in (lower) 24 ft 6 in
Length (Puma) 21 ft 4 in
Height (Puma) 9 ft 9 in (Lion) 8 ft 6 in
Wing area 195 sq ft
Weights:
(Avro 539) Tare weight 1,670 lb
All-up weight 2,119 lb

Production:
One aircraft only - Avro 539 G-EALG, c/n 539/1, first flown 29.8.19; rebuilt 1920 as Avro 539A G-EALG, c/n 539A/1; rebuilt 1921 as Avro 539B G-EAXM, c/n 539B/1, damaged beyond repair at Hamble 13.7.21

Avro 534 Baby

  After the Armistice A. V. Roe was impatient to return to low-powered flying and build a light aircraft of 600 lb all-up weight with an engine of 20-30 hp which could disport itself within the confines of any large field. Chief designer Roy Chadwick favoured an aeroplane with a heavier wing loading, an engine of 40-50 hp, and cross-country capability. Final design was dictated by engine availability, the only suitable one in existence being A. V. Roe’s 35 hp Green which had been preserved by Mr Fred May of the Green Engine Co Ltd. It is said that this engine was fitted originally to the first Avro Type D biplane for Pixton’s flight to Brighton on May 6, 1911.
  The little Avro 534 was designed round this veteran powerplant and although at first named the ‘Popular’, soon acquired the type name Baby. The Green Engine Co completely modernised the engine and fitted aluminium pistons, new type camshaft, valve gear and oil pressure regulator. Cooling was by traditional nose radiator. The Baby was an equal-span, single bay biplane of wire-braced, fabric-covered wooden construction with ailerons on all four wings and the balance area of the famous Avro comma rudder was increased slightly to make it an accurate circle. About a dozen of these machines were built singly at Hamble and eight of them helped to lay sure foundations for the light aeroplane movement which came seven years later. Their Green engines, even lighter than the remodelled original, were specially built by Peter Brotherhood Ltd of Peterborough from a complete set of manufacturing drawings found in the Green Engine Co’s archives.
  The prototype Baby emerged on April 30, 1919, and it is said that its total flying life of 2 minutes ended when H. A. Hamersley spun into the Hamble foreshore from 300 ft when the ignition switches were cut inadvertently. The same pilot won the handicap section of the Aerial Derby at Hendon on June 21, 1919, at an average speed of 70-3 mph in K-131, usually regarded as the first Avro Baby. It certainly had the same engine but a number of minor differences identify it as actually the second machine of the type, first flown at Hamble on May 10, 1919. As if to emphasise that the Baby was no low-powered freak, Hamersley won the Victory Trophy Race at Hendon at 77 mph in July and flew nonstop from Hounslow Heath to Brussels in 2 hours 50 minutes in August, afterwards flying on to the First Air Traffic Exhibition at Amsterdam. The machine was dazzle painted and carried the words ‘Avro Baby’ in large white letters. The original marking K-131 remained, but for the overseas flight the permanent registration G-EACQ was painted in white on the sloping decking.
  On its return the elevator control system was modified so that cables previously carried within the fuselage now ran externally from double-ended cranks mounted on a cross shaft behind the pilot. The Baby then gave aerobatic displays along the South Coast to publicise the joyriding Avro 504Ks. Chadwick, who had just been taught to fly by Hamersley, frequently went cross-country in it but when flying low on January 13, 1920, an abnormal bump deposited the aircraft on the ground in the garden of the Rev Everard Verdon Roe’s Hamble Vicarage. Chadwick was gravely injured and eye-witness accounts suggest that the Baby was a complete wreck and it is probable that the rebuilt aircraft incorporated only the engine and primary structure of the earlier machine. Registration G-EACQ was retained and many detail improvements were made. These included a raised tailplane; tapered ailerons; a slightly taller, oval shaped rudder; a new oil tank without projecting filler cap; more streamlined interplane struts and the pitot head repositioned on the top wing. H. J. ‘Bert’ Hinkler bought it in April 1920 and on May 31 made a sensational 650 mile nonstop flight from Croydon to Turin in 9 1/2 hours for which he was later awarded the Britannia Trophy. He went on to Rome and flew back in easy stages, reaching Hamble on June 10. The machine was then exhibited at the Olympia Aero Show and on July 24 came second in the Aerial Derby Handicap at Hendon, piloted by the owner.
  The Avro 534A Water Baby, a second machine built in October 1919, was a twin-float seaplane similar to the rebuilt prototype. It had an unbalanced rudder hinged to a large fin, and a slight reduction in lower mainplane span which imparted a slant to the interplane struts. Flown from Southampton Water, the Water Baby performed very creditably despite water soakage.
  Designated Avro 534B by virtue of its plywood covered fuselage and slightly shortened bottom wing, the third Baby G-EAUG reverted to the perfectly circular rudder. Piloted by Hamersley it just beat Hinkler to win the 1920 Aerial Derby Handicap but was destroyed soon afterwards with serious injuries to Avro pilot D. G. Westgarth-Heslam. The control column universal joint failed during a forced landing with choked carburettor while he was en route to Martlesham to fly the Avro 547A in the Air Ministry Commercial Aeroplane Competition.
  The next machine, produced in July 1920, was the Avro 543 Baby G-EAUM two-seater which housed pilot and passenger in an enlarged single cockpit. It was otherwise a standard Baby with the front fuselage lengthened by 2 ft 6 in and on test carried Hinkler and Chadwick to 11,000 ft. Flown by Capt T. Tulley, it averaged 73-67 mph in the 1921 Aerial Derby but was forced down at Brooklands and fared no better in the 1922 and 1923 King’s Cup Races. In 1926 ’UM went to Shoreham under the joint ownership of L. E. R. Bellairs and F. G. Miles who removed the ancient Green and attendant plumbing in favour of a 60 hp A.D.C. Cirrus I air-cooled engine, gravity fed from a large centre-section tank. A later owner R. A. Whitehead overturned it in a forced landing at Bury St Edmunds during the 1928 King’s Cup Race, after which it was bought by H. H. Leech for the 1929 race. He sold it to Roper Brown at Southend in 1932. A projected Cirrus I conversion of a single-seat Baby as the Avro 534G did not materialise.
  All later Babies were equally remarkable. Avro 534C G-EAXL had the span of both wings further reduced for the Aerial Derby of July 16, 1921, but Hinkler forced landed at Sidcup, Kent. During an air test at Hamble on September 6, 1922 (eve of the first King’s Cup Race), the engine cut at low altitude and Hinkler got a ducking when ’XL fell into Southampton Water. The special Avro 534D Baby G-EAYM which first flew at Hamble on September 14, 1921, had all-steel engine bearers, oversize radiator, extra cowling louvres, slightly taller undercarriage, and a luggage locker behind the pilot’s seat. It was built to the order of Col E. Villiers, an ex-RAF pilot who flew it at Dum Dum, Calcutta, as a means of inspecting his business interests. This Baby was still flying in 1928.
  Projected variants with folding wings (Avro 534E) and 100 hp Bristol Lucifer (Avro 534F) were not built, but in accordance with the Soviet practice of buying single examples of outstanding aircraft, standard Avro 534 single-seater G-EBDA was collected from Hamble by Russian pilot Gvajta in June 1922. His delivery flight from London to Moscow was the first ever made between these capitals. Last of the breed to fly was the Avro 554 Antarctic Baby, a photographic survey development of the projected Le Rhone engined Avro 544 Baby two-seater. Identified by rounded wingtips it was built in 1921 for the Shackleton-Rowett South Polar Expedition. Limited shipboard stowage space called for swift dismantling and erection by gloved hands without rigging problems. Tubular steel struts therefore replaced flying wires, N-type interplane struts were used, and all bolts were extra large. An 80 hp Le Rhone rotary completely altered the shape of the nose and the tailplane was raised above the fuselage and adjustable for incidence on the ground. After trials on Southampton Water by Maj C. R. Carr, Shackleton’s pilot, the Avro 554 was embarked in the Quest at Tower Bridge and left for the far south. Engine trouble in the Quest compelled Shackleton to proceed direct to Rio de Janeiro, so that he was unable to collect parts of the aircraft left at Cape Town by an earlier vessel, or to use the 554 on the expedition. The missing components were collected on the return journey and the complete aeroplane arrived back in the Quest on September 16, 1922.
  In 1923 the Antarctic Baby was purchased by Capt R. S. Grandy on behalf of Bowring Bros Ltd of St John’s and registered G-EBFE for test flying on wheels at Hamble. Fitted with skis, it was shipped to Newfoundland for seal spotting and occupied a platform on the stern of Bowring’s sealer Neptune. A hostile crew refused to allow it to fly but in 1924 Grandy took off from an icefloe alongside the Eagle and spotted a herd of 125,000 seals. The Baby was flown for three more seasons by C. S. ‘Jack’ Caldwell and retired in favour of an Avro Avian in 1927.
  After the 1920 Aerial Derby Hinkler decided to ship the Baby G-EACQ to Australia and had the engine bay modified so that he could do single handed overhauls in the outback and even remove cylinders with the engine in situ. The machine was first exhibited at the Royal Sydney Easter Show and on April 11, 1921, Hinkler made the now historic 800 mile nonstop flight from Sydney to his native Bundaberg where he landed in the main street and taxied up to his garden gate. The Baby had now been registered G-AUCQ and during the return flight on April 27, overturned on a remote beach in tropical rain. When righted, it was towed 16 miles to Newcastle by horse team and shipped to Sydney where it was repaired and sold to H. Broadsmith who designed and built a set of floats to the order of a film company. Resulting from several flights from the waters of Botany Bay in 1922, he advised the company that the Baby would be unsuitable for operation in New Guinea and ’CQ later reverted to a wheeled undercarriage with the front legs farther aft as on Villers’ Avro 534D. After a period as an attraction at a Queensland garage, it passed to W. E. Hart and later to Fitzalan of Melbourne, to whom it was re-registered VH-UCQ in 1928. As late as December 1936 a flight of 200 miles from Melbourne to Hamilton, Victoria, was made by final owner J. J. Smith. Though it was withdrawn from use in 1937, J. J. Smith kept the Baby in store until he presented it to the Queensland Museum, Brisbane, where it was placed on display beside Hinkler’s Avro Avian G-EBOV in 1972 painted as G-EACQ.
  One Baby was used by H. G. Leigh for experiments with narrow-chord multiple aerofoils at Hamble in December 1920, but a number of unused airframes remained in store until F. G. Miles bought them early in 1929. His prototype Southern Martlet G-AAII, first flown at Shoreham in August that year, was not (as is often supposed) a conversion of one of these. It resembled the Baby externally and used most of its metal fittings, but the timber work was completely new and the engine mounting, undercarriage and tail unit were of entirely new design.


SPECIFICATION AND DATA
   Manufacturer: A. V. Roe and Co. Ltd., Hamble Aerodrome, near Southampton, Hants.
   Power Plants:
   (Avro 534 and 543) One 35 h.p. Green
   (Avro 543) One 60 h.p. A.D.C. Cirrus I
   (Avro 554) One 80 h.p. Le Rhone

Dimensions, Weights and Performances:

   Avro 534 Avro 534C Avro 534D Avro 543 Avro 554
Span (upper) 25 ft. 0 in. 20 ft. 0 in. 25 ft. 0 in. 25 ft. 0 in. 26 ft. 3 in.
Span (lower) 25 ft. 0 in. 18 ft. 0 in. 23 ft. 0 in. 23 ft. 0 in. 24 ft. 0 in.
Length 17 ft. 6 in. 17 ft. 6 in. 17 ft. 6 in. 20 ft. 0 in. 22 ft. 5 in.
Height 7 ft. 6 in. 7 ft. 6 in. 7 ft. 6 in. 7 ft. 6 in. 10 ft. 3 in.
Wing area 180 sq. ft. - 176.5 sq. ft. 176.5 sq. ft. 184.5 sq. ft
Tare weight 625 lb.* - 656 lb. 630 lb. 980 lb.
All-up weight 857 lb. - 950 lb. 970 lb. 1,569 lb.
Maximum speed 78 m.p.h. - - 82 m.p.h.** 90 m.p.h.
Cruising speed 70 m.p.h. - - 70 m.p.h. 70 m.p.h.
Initial climb 500 ft./min. - - 450 ft./min. 330 ft./min.
Range 240 miles - 370 miles 225 miles 190 miles

*The Leigh multiple aerofoil Baby 675 lb. and 921 lb.
**98 m.p.h. with A.D.C. Cirrus I engine.


Production:

Constructor's No. Registered Details
and Registration
   Prototype: crashed at Hamble 30.4.19
534/1 K-131 29.5.19 Avro 534: later G-EACQ; first flown 16.5.19; 4.20 H. J. Hinkler; to Australia 4.21 as G-AUCQ; re-rcgistered 1928 as VH-UCQ: s.o.r.* 1936
534/2 G-EAPS 21.11.19 Avro 534A: crashed 7.9.21
534B/1 G-EA UG 9.7.20 Avro 534B: crashed near Ipswich about 3.8.20
543/1 G-EAUM 12.7.20 Avro 543: C. of A. issued 3.8.23; c/n amended to 5062 at engine change 1926; 11.27 L. E. R. Bcllairs and F. G. Miles; 7.28 R. A. Whitehead; 9.28 H. H. Leech; 9.29 H. R. A. Edwards; 8.32 Roper Brown; s.o.r. 12.34
534C/1 G-EAXL 27.6.21 Avro 534C: crashed in Southampton Water 6.9.22
5049 G-EAYM 17.9.21 Avro 534D: first flown 14.9.21; withdrawn from use at Calcutta in 1929
5064 G-EBDA 28.4.22 Avro 534: sold in Russia 13.6.22
5040 nil - Avro 554: built 1921; registered to Avro 1.2.23 as G-EBFE; to Newfoundland 1923; scrapped 1927

Avro 548

  By 1918 successful development of the inline engine was already ending the long career of the rotary. The inline was not only less complex and more easily maintained, but less extravagant in fuel and oil. It was not therefore surprising that A. V. Roe’s ingenious civil adaptations of the 504K embraced an economical engine of this type, particular as tens of surplus thousands were to be had at give-away prices.
  Experiments began at Hamble in October 1919 with the Avro 545 G-EAPR, an experimental 504K with 90 hp Curtiss OX-5. This American eight-cylinder Vee water-cooled engine was cooled by spiral tube radiators on each side of the front cockpit in the manner of the Avro Type E prototype of an earlier era. Such an installation, with its heavy and potentially troublesome plumbing, would not have appealed to private owners and final choice fell on the air-cooled 80 hp Renault, a similar engine which drove a four bladed wooden airscrew.
  Designated Avro 548, first flown at Hamble by H. A. Hamersley late in 1919, flown to Farnborough for checks on January 13, 1920, and certificated in the following March, the first Renault Avro G-EAPQ was a 504K with the dual control removed to carry two passengers in tandem behind the pilot. Fuel, entirely gravity fed, was carried in a large centre-section tank and a false decking covered the large rear cockpit so that each occupant had his own windscreen. This machine was the only Avro 548 to have external elevator control wires running from cranks above the lower wing root. Silver overall with polished cowlings, it graced the Avro stand at the Olympia Aero Show, London, in July 1920 without markings as the ‘Avro Tourist’. The third Avro 548, G-EALF, was available for demonstration flights at Hendon during the Show and on July 28 F/Lt Leslie flew Prince Alfonso d’Orleans to Farnborough in it.
  The trade slump killed any potential market, and a projected trainer version (Avro 553) was shelved, but the prototype was repainted in wartime
drab for Capt E. D. C. Herne who used it for a photographic survey of the whole of England, the entire coastline of Belgium and France as well as all the major Belgian inland towns. When King George V visited Belfast, ’PQ was flown 700 miles from Croydon to Belfast and back in one day, yet total repairs after 30,000 miles in 18 months amounted to only £2 for a set of control cables, and 3d for a valve spring. W. G. Pudney afterwards acquired it and ran a joyriding business at Croydon throughout 1922.
  Three other Avros 548s built at Hamble were without the false decking and had a large, double rear cockpit. One was sold in Uruguay and another, G-EAFH (formerly K-147, 504K test-bed for the 170 hp A.B.C. Wasp I), spent 1921 at Swansea with the Welsh Aviation Company and won all three races at the Croydon Meeting of September 17, 1921, piloted by F. G. M. Sparks. When the firm went into liquidation, pioneer private owner Dr E.
Whitehead Reid of Bekesbourne, Canterbury, bought it for a mere £12 10s, converted it to two-seater and flew it in and out of fields on his professional rounds until 1927. G-EAFH then returned to joyriding, first at Squires Gate and in 1931 at Southport sands and with the Giro Aviation Co, finally crashing there on May 31, 1935, during a low altitude aerobatic display. A. V. Roe and Co built only three other 548s, dual trainers G-EBIT - ’IV for the North Sea Aerial and General Transport Co Reserve School at Brough in 1924.
  The majority of Avro 548s were conversions made by outside firms such as the Aircraft Disposal Co which produced ten at Croydon. Only the first of these, G-EAYD, resembled Avro’s prototype with three separate cockpits. The remainder included five for Reserve Training at Stag Lane by the de Havilland School of Flying, one of which was the former Avro Transport Company 504K G-EAAL. Named Vida, the latter eventually passed into private ownership at Stag Lane. G-EBPJ, privately owned in 1926 by Nigel Norman, served the Norfolk and Norwich Aero Club at Mousehold 1927-28; and ’PO went to Newcastle Aero Club at Cramlington in the same year.
  Surrey Flying Services built three; G-EBAJ for airborne radio telephony experiments by Marconi’s Wireless Telegraph Co at Croydon and Chelmsford; G-EBBP for private owner Sir Derwent Hall Caine (which later in 1922 reverted to the company for instructional use); and dual trainer G-AABW in 1928. The only difference between these and the genuine Avro-built 548 was the bulged under-cowling. When Marconi ceased experiments in 1926, G-EBAJ joined the rapidly expanding fleet of the Henderson School of Flying at Brooklands. A. B. H. Youell flew it at the next year’s Bournemouth Easter Meeting, winning the Business Houses Handicap on April 16, 1927, at an average speed of 74 mph. On October 1 that year it took a prominent part in welcoming home the victorious Schneider Trophy team by flying round Croydon with suitably inscribed yellow banners attached to a crude metal framework. The Henderson School and its successor, the Brooklands School of Flying, owned nine 548s, six of which they built from spares. Although primarily intended for instructional work, the 548s always went joyriding at coast resorts such as Skegness and Canvey Island in the summer. Two, G-EBRD and ’SC, shipped to South Africa for a pleasure flying season in 1927-28, took part in Cape Town’s first air display on December 11, 1927.
  The most important Henderson 548 was G-EAJB, one of Avro’s original 1919 civil 504Ks which had been used at Filton for some years by the Bristol Aeroplane Co as a Lucifer engine test-bed. Standard 504K shock absorbers now replaced the special oleo units used at Bristol but ’JB retained the 504N-type ailerons with curved trailing edge. The only other Avro 548 so fitted was Henderson’s second machine G-EBRD, built for South Africa.
  In 1925 Maj F. B. Halford of the Aircraft Disposal Co modernised the 80 hp Renault by fitting redesigned cylinder heads and valve gear which raised the power output to 120 hp. This engine, the Airdisco, was fitted into one of the company’s surplus 504K airframes to create the first Avro 548A. Registered G-EBKN, it had greatly improved all-round performance and became the lively mount of Shoreham private owner A. G. Head. Not to be outdone in publicity by A. V. Roe and Co, donors of an Avro 504R to the Lancashire Aero Club in July 1926, the Aircraft Disposal Co simultaneously presented the club with one of their 548 conversions G-EBOK. Soon afterwards, on October 2, T. Neville Stack flew ’OK to victory in the Yorkshire Open Handicap Race at Sherburn, beating the Brough 548As G-EBIT and ’IU. Together with ’IV, these had been reengined with Airdiscos but were sold to joyride concerns in 1928 along with ’OK. G-EBIV went to Surrey Flying Services, Croydon, while ’IT and ’IU joined ’OK at Squires Gate and there became even better known than the 504K.
  The last two British 548s, G-ABMB and ’SV, were built at Barton by Berkshire Aviation Tours Ltd in 1931 for the Giro Aviation Co, their sole cross-country flying being the delivery flight to Southport where they worked the beaches for several years. Both were replaced by D. H. Fox Moths in 1934-35 but remained fully rigged in the hangar at Hesketh Park until 1938.
  A few Avro 548 conversions were also made overseas. The Canadian Aircraft Co Ltd of Winnipeg, importers of six 80 hp Renaults in April 1920, built three machines and retained two for charter flying. The third was converted for the McCall Hanrahan Aero Service of Calgary but crashed in less than a fortnight. In 1928 they also built the Hawk-Clark Y-Avro Mallard G-CASY for W. P. A. Straith, using an old 504K fuselage with a 75 hp Rolls-Royce Hawk engine and Clark Y section wings. In Australia Matthews Aviation Ltd replaced the Dyak in G-AUBG by an Airdisco; and G-AUBK, flown by E. W. Percival in the Australian Aerial Derby with an 80 hp Renault on May 6, 1922, also later received an Airdisco. The only other example, G-AUEW, started life as a Clerget 504K, but was modified progressively to 548 and 548A by E. W. Beckham and Courier Aircraft Ltd of Brisbane 1926-27.


Specification and data

Manufacturers:
   A. V. Roe and Co. Ltd., Newton Heath, Manchester; and Hamble Aerodrome, near Southampton, Hants.
   The Aircraft Disposal Co. Ltd., Croydon Aerodrome, Surrey
   Berkshire Aviation Tours Ltd., Barton Aerodrome, Manchester
   The Canadian Aircraft Co. Ltd., Winnipeg, Manitoba, Canada
   The Henderson School of Flying Ltd., Brooklands Aerodrome, Surrey
   Surrey Flying Services Ltd., Croydon Aerodrome, Surrey
Power Plants:
   (Avro 545) One 90 h.p. Curtiss OX-5
   (Avro 548) One 80 h.p. Renault
   (Avro 548A) One 120 h.p. Airdisco
Dimensions:
   Span 36 ft. 0 in.
   Length 29 ft. 5 in.
   Height 10 ft. 5 in.
   Wing area 330 sq. ft.
Weights and Performances:
Avro 545 Avro 548 Avro 548A
Tare weight 1,241 lb. 1,338 lb. 1,460 lb.
All-up weight 1,829 lb. 1,943 lb. 2,150 lb.
Maximum speed - 80 m.p.h. 91 m.p.h.
Cruising speed 70 m.p.h. 65 m.p.h. 84 m.p.h.
Initial climb - 350 ft./min. 400 ft./min.
Ceiling - - 11,200 ft.
Range 210 miles 175 miles 300 miles




Avro 553

  A training version of the Avro 548 (80 hp Renault)

The Duigan Biplane

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  Having achieved his objectives, Duigan returned home. There he built a very similar machine to the Avro which crashed on its first flight on February 17, 1913. His British aeroplane was put up for sale with engine for £380 but was almost immediately reduced to £180, no doubt because the engine had been sold separately. The airframe was purchased by the Lakes Flying Company and it was delivered to Windermere on June 4, 1912. Here it was rebuilt as the centre float seaplane Sea Bird which H. Stanley Adams flew off the lake for the first time on August 28, 1912. The company entirely redesigned the front end of the fuselage to accept a 50 hp Gnome rotary, the upper half of which was cowled and gave a cocked-up appearance to the nose. New three-bay, warping mainplanes of Eiffel 12 section and 8-5 aspect ratio were also fitted. The machine proved much faster than the old Avro-built Water Bird and after it has been fitted with an improved twin float undercarriage, carried large numbers of holiday makers during 1912-13.
  At the end of 1912 the machine was tested with an amphibious undercarriage but trials came to an end on December 18, 1912, when Sea Bird piloted by Lt J.F.A. Trotter was caught by a gust of wind and the lower port wing struck the water. In January 1915 the Lakes Flying Company was taken over by the Northern Aircraft Company Ltd and thereafter the machine was generally referred to as the Avro Biplane Tractor. It was equipped with dual control soon after and at the beginning of June was fitted with new floats. Unfortunately, pupil R. Buck took off in the Avro for his Vol-plane test on June 5 unaware that the latter had altered the centre of gravity. On switching off the engine to begin his glide approach, Buck failed to lower the nose sufficiently and the machine stalled at 300 ft, crashing into the lake tail first. Miraculously Buck was unhurt but the Sea Bird was destroyed.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company, Brownsfield Mills, Great Ancoats Street, Manchester; and Brooklands Aerodrome, Byfleet, Surrey.
   Rebuilt by The Lakes Flying Company, Cockshott, Lake Windermere, Westmorland
   Power Plants:
   (Sea Bird) One 50 h.p. Gnome
   Dimensions:
   (Sea Bird) Span 39 ft. 4 in. Length 29 ft. 4 in.
   Height 10 ft. 6 in. Wing area 350 sq. ft.
   Performance:
   (Sea Bird) Maximum speed 62 m.p.h.

   Production: One aircraft only, first flown 2.12; converted into the Lakes Sea Bird 10.12, crashed at Windermere 6.15

Avro Curtiss-type

  In the summer of 1910 A. V. Roe and Company declared its willingness to build aeroplanes to other people’s designs and the first such aircraft was a Farman-type biplane for the Bolton business man and manufacturer of Avro aero engines, Maurice F. Edwards. Bolts, fittings and bracing wires were also supplied to Miss Lilian Bland who built and flew the Mayfly biplane of her own design at Carnamony, Belfast. Each of these aircraft was fitted with one of the few examples of the 20hp two-cylinder, horizontally-opposed, air-cooled Avro engines. The Farman-type evidently did not met with much success as 18 months later, at the end of 1912, the engine and airframe were advertised for sale in new condition for £45 and £60 respectively.
  A Curtiss-type, of the familiar outrigger-tail and front-elevator variety with 50 hp Gnome rotary, was built in 1911 to the order of Capt E. W. Wakefield of Kendal. Neither this nor the Farman-type mentioned above was given an Avro designation. Mainplanes were of unequal span and lateral control was by four ailerons on the upper mainplane, the inner and larger pair having semi-circular trailing edges. It was built at Manchester and delivered at Brooklands for test flying on May 25, 1911, though it did not fly until June 19.
  After a short period with the Avro School during which it was flown by F. P. Raynham, R. C. Kemp, F. Conway-Jenkins and Louis Noel, the Avro-Curtiss was dismantled on July 7, 1911, and transferred to Lake Windermere where Capt Wakefield replaced the wheels by a single 12 ft, three step, canvas covered mahogany float built by Messrs Borwick and Sons of Bowness-on-Windermere and small cylindrical floats were fitted below the wingtips. During the course of the re-erection and modification much dissatisfaction was expressed with the standard of the machine’s construction and over the discovery of a crack below one cylinder of the Gnome engine. Legal proceedings were begun against A. V. Roe and Company with Capt Wakefield claiming £212 for the engine and £50 on account of the Curtiss-type not being built to contract but there was no recorded outcome to the case. The aircraft made its first flight in marine form on November 25, 1911, piloted by H. Stanley Adams, a former pupil of the Avro School. The success of the first test flights prompted Wakefield to invite the press to view an exhibition flight two days later. The event was reported at some length in The Westmoreland Gazette and the reference to the machine’s bird-like properties are thought to have prompted the adoption of the name ‘Lakes Water Bird’ by which the machine was subsequently known. Water Bird was the first consistently successful seaplane in the United Kingdom and during the next few months its fame spread quickly and a considerable waterborne joyriding business was done. Sixty flights were made in the first 38 days, the best being of 20 minutes duration up to a height of 800 ft. On December 7, 1911, Stanley Adams flew the whole length of the lake at a speed of approximately 40 mph at a height of between 60 and 100 ft. These operations continued throughout the winter, but the night of March 29-30, 1912, brought gales which demolished the lakeside hangar at Cockshott and damaged Water Bird beyond repair. Its float, tailplane and rudder (the last still proudly displaying the legend ‘A.V. Roe and Company, Manchester’) are still in the possession of the Wakefield family at Windermere.
  Water Bird’s successor, identical, but entirely designed and built at Windermere by Capt Wakefield’s Lakes Flying Company later in 1912, was known as Water Hen. Its only Avro component was the airscrew and at first it could be distinguished from its Avro-built forerunner by the wingtip floats and straight trailing edges to the ailerons. These were mounted parallel to the chord line of the mainplanes instead of at a considerable angle to it. They were later remounted in the angled position but by that time more drastic modifications had been made and all similarity to Water Bird ceased.


SPECIFICATION AND DATA
   Manufacturers: A. V. Roe and Company, Brownsfield Mills, Great Ancoats Street, Manchester; and Brooklands Aerodrome, Byfleet, Surrey
   Power Plant: One 50 h.p. Gnome
   Dimensions:
   Span (upper) 41 ft. 0 in. (lower) 32 ft. 0 in.
   Length 36 ft. 5 in. Wing area 365 sq. ft.
   Weights: Tare weight 780 lb. All-up weight 1,130 lb.
   Performance: Maximum speed 45 m.p.h. Ceiling 800 ft.
   Production: One aircraft only, first flown as landplane 6.11; first flown as seaplane 25.11.11, damaged beyond repair at Cockshott, Windermere 30.3.12