Centennial Perspective
British Aircraft of WWI. Vol.7: Experimental Fighters Part 3

C.Owers - British Aircraft of WWI. Vol.7: Experimental Fighters Part 3 /Centennial Perspective/ (81)

The A.D. Sparrow Scout

  The Admiralty was responsible for the aerial defence of the United Kingdom when war broke out in 1914. The air raids by German airships led to the Admiralty’s Air Department proposing in 1915 a fighter capable of operating in the anti-airship role. The Air Department’s “D” Section - the “D” standing for Drawing Office Section, but more accurately would be Design Section, as the office, under Harris Booth, produced its own designs and then contracted private firms to build them. Booth’s anti-zeppelin design, named Sparrow, was an unusual single bay biplane powered by a 100-hp Gnome Monosoupape rotary engine in pusher configuration at the rear of the nacelle.
  In order to save on materials that were in short supply, Booth made use of ordinary mild steel for all fittings, even designing special turnbuckles for the machine. The A.D. Scout was unorthodox in having a nacelle situated high with the upper wing spars meeting the top longerons of the nacelle. Strut connected ailerons were fitted to both wings. The pilot had an excellent field of vision; however, the wheel track was only 2 1/2 feet, and even with the skids incorporated into the landing gear, the high thrust line of the engine with the narrow track could only have resulted in gross unwieldiness in take-off, landing and taxiing.
  The tailplane spanned approximately 63% of the span. The tailplane was set high on the tail booms that were parallel in plan and elevation. Twin fins and rudders were fitted. The late Jack Bruce commented on the type: - What astonishes me most is the absence of any transverse connexion between the lower ends of the fins. What sublime faith they must have had in cables.
  Two machines were ordered from Hewlett & Blondeau of Leagrave, Bedfordshire, under Contract No. CP38552/16, (serial Nos. 1452 - 1453), and two from Blackburn Aeroplane & Motor Co Ltd of Leeds, (Nos. 1536 and 1537).
  The report of “Y” Section for the W/E 22 July 1915, recorded for Blackburn C.P.76201. Firm unable to tender for two Sparrow Biplanes - ask tender held over for present. Construction at Blackburn still went ahead, their tender being officially accepted nearly eight months later in the W/E 24 March 1916, their contract being No. CP104662/16.
  “D” Section was intimately involved with the manufacturers, and for the W/E 20 August 1915, reported that During the week a number of questions of approvals of design have been dealt with, notably in the case of the Hewlett & Blondeau Sparrows, the 150 H.P single seater Avro and the Handley Page machines. Hewlett & Blondeau were concerned about the narrow undercarriage and they designed and built an alternative undercarriage that had a wider track but this was rejected and the original had to be adhered to.
  The following reports for the next two weeks noted that during the week Messrs. Hewlett & Blondeau and Messrs. Blackburn have been visited in connection with the completion of the Sparrow Machines. Delivery of this is fixed to take place at Chingford, the trial flight being carried out by an Admiralty Pilot.
  During the W/E 25 Sept 1915, “D” Section personnel paid a visit to Chingford regarding the erection of the Sparrows. This would have been No. 1536 that was being erected there by the makers from the 23rd.
  The last report to mention the Scout was that of “K” Section. Lt Hardstaff visited Chingford on Monday 6 February 1916, re the A.D. Scouts. With regard to modifications to be carried out on the aileron control nothing has so far been done. No. 1536 had completed its tests by then, and was dismantled by 17 March. No. 1537 was tested at Chingford, then sent to the Central Supply Depot, White City.
  The Hewlett & Blondeau constructed machines were both tested at Chingford. No. 1452 being delivered on 15 November 1915, and tested on 2 December.
  Nos. 1452 and 1536 were reported on 1 April 1916 as - Sparrows dismantled at Chingford.
  Both Hewlett & Blondeau machines were sent to White City, and all four Sparrows were deleted on 7 June 1916. However, the Daily Reports noted that at the Central Supply Depot the list of aircraft in store included four A.D. Scouts unpacked. It seems that, as usual, the paperwork and the activity on the ground were not in sequence, although the machines were officially deleted, they were not destroyed on that date.
  The machines are believed to have been heavier than estimated and to have had unfavorable flight characteristics. It was soon apparent that ordinary aircraft could undertake the task of anti-zeppelin fighters and that the A.D. Scout was a dead end. The Davis recoilless gun has been presented as the proposed armament for the A.D. Scout, however the near impossibility of mounting that weapon in the airframe rules this out, even if it was considered. Reports only mention the Lewis gun as the armament.

A.D. Sparrow Scout Specifications
Span 33 ft 5 in
Length 22 ft 9 in
Height 10 ft 3 in
Speed Max 84 mph
Climb to 3,000 ft 5 min
Climb to 6,500 ft 12 min
Climb to 10,000 ft 25 min
Endurance 216 hrs
Source: J.M. Bruce data.
A.D. Sparrow Scout
The A.D. Scout, or Sparrow, was designed in 1915 as an anti-Zeppelin fighter. Powered by an 80 hp Gnome rotary and intended to be armed with a Davis recoilless quick-firing gun, it was tricky to fly and land and was quickly abandoned.
The A.D. Scout at Chingford. The man caught by the photograph in mid-air may have fallen from the nacelle, but the circumstances have never been explained. There is a man on the footsteps that were attached to the landing gear strut. The men at the rear of the aircraft are holding the tail down. It would appear that the man's weight caused problems and he departed the footholds on the nacelle by the quickest means available! The red ring RNAS markings may be noted under the lower starboard wing.
Views of an A.D. Scout under construction. Unfortunately, which manufacturer's works is unknown. (Ingenium. CAVM-03862 & 03860).
A.D. Sparrow Scout
A.D. Sparrow Scout
Installation of an Arab engine in an AD flying boat at Isle of Grain, 20 November 1917.
The Alcock A.1

  John W. Alcock, with Arthur Whitten Brown, earned fame as the pilot of the first aircraft to fly the Atlantic in 1919. Alcock had gained his Royal Aero Club Certificate in November 1912. He joined the RNAS in November 1914, and after serving as an instructor at Eastchurch, he was sent to the Mediterranean theatre of operations.
  In 1917, Flt Lt Alcock was serving with No.2 Wing, RNAS, then based at Mudros, in the Agean. Alcock made a surprise attack on an enemy reconnaissance seaplane escorted by two fighting seaplanes on 27 July 1917. The enemy seaplanes were attempting a reconnaissance of Lemnos where the RNAS had established itself. Alcock’s Sopwith Camel sent one of the fighting seaplanes down apparently in trouble. He then turned to the second fighter and it landed near Seddel Bahr in a damaged condition. In the meantime, the remaining seaplane alighted where it was protected by Turkish artillery.
  Alcock and Flt Lt H.T. Mellings attacked another similar trio of seaplanes on 30 September. Alcock was again in a Camel and Mellings in a Sopwith Triplane. Alcock forced one to alight and its wounded pilot was eventually picked up by the Royal Navy. Mellings also scored, his opponent diving into the sea where it broke up.
  The official RFC/RAF history, The War in the Air, mentions this combat but suggests that while Alcock’s aircraft is mentioned in the official reports as a Camel, there is some evidence it was Alcock’s own design. The history then relates how a twin-engine German bomber had been shot down by Naval pilots in April 1917, on the Macedonian front. From this machine a Benz engine was recovered in good condition. This engine was sent to Mudros and Alcock had been given permission to build an aircraft around it. According to Lt Col L.H. Strain, Alcock built his fighter but had not tried it and was going to test it on the morning of the 30th when the raid took place. The engine had been warmed up but Alcock was caught in his bath when the enemy’s reconnaissance machines came over. He hurriedly put on his pyjamas and ran out to his machine and took off, quickly catching up with the enemy machines as his aircraft was 20 mph faster than anything else the British had. Alcock had no knowledge of aerodynamics, etc., but he had a natural genius for knowing where stresses came and how to meet them.
  That evening Alcock left in the Handley Page O/100 to bomb Constantinople and Haidar Pasha’s railway stations. Engine trouble forced the bomber to turn back and it force landed in the Gulf of Xeros.The crew eventually had to swim to shore where they were captured and became prisoners of the Turks.
  The late Jack Bruce’s researches with former members of No. 2 Wing, RNAS, who were with Alcock on Mudros, present a different story of the Alcock Scout. From photographs it is evident that it was a two-bay rotary powered biplane. Alcock called it the Sopwith Mouse due to the number of Sopwith components used in its manufacture, but has become more commonly known as the Alcock A.1 The fuselage appears to have used parts of a Triplane that crashed at Mudros on 3 September 1917. The upper wing was modified from that of a Sopwith Pup, while the lower wings were modified Triplane components. Ailerons were fitted to the upper wings only and were longer than those of the Pup. The horizontal tailplane and elevators came from a Camel. The rear fuselage, fin and rudder were of original design. The resultant two-bay aircraft was a well-proportioned machine of clean lines. The fuselage was mounted mid-gap in order to bring the pilot’s eyes level with the upper wing, giving him a good field of vision. The engine was a 110-h.p. Clerget. Armament comprised a single Vickers gun mounted on the aircraft’s centre-line on the fuselage decking in front of the cockpit.
  It appears that rather than Alcock being the designer, the stress calculations for the machine were carried out by Commander Constantine of the Greek Navy, who was in command of the Greek air contingent on Mudros.
  Alcock never got to fly his Mouse as he was taken prisoner before it was completed. While in jail in Constantinople Alcock received a message from Wing-Captain F.R. Scarlett which read: Your baby was taken for an airing, but is still having trouble with teeth. She has now been fitted with new clothing. Now a great improvement in health. It is believed the machine first flew in October 1917.
  Norman Henry Starbuck, RNAS, was posted to the Aegean and flew the A.1 on 25 March 1918. He wrote that it Cartwheeled both ways and spun to the right. She came out of everything alright. This type of machine has never been stunted before. Very nice to fly, a bit nose heavy and heavy on controls but quick in answering.
  Flown at Mudros and Stavros, the A.1 was eventually written off in a crash.

Specifications: No accurate dimensions are recorded but the following are approximate based on the known components that were used in its construction.
Span: 24 ft 3 in upper; 23 ft lower. Length: 19 ft 1 1/2 in.
Alcock A.1
The A.1's Sopwith heritage is shown in these photographs.
The writer makes no apology for including this less than perfect view of the one-off Alcock A I, whose genesis encapsulated the truly remarkable spirit and initiative of some RNAS fliers. Designed and built on the Aegean island of Mudros by RNAS pilot John Alcock, presumably as a spare time venture, the single-seat fighter made use of some existing Sopwith components, as both Pups and Triplanes had operated from the island. However, it was what Alcock did with these that was so impressive, building them into an intelligently conceived airframe that was just about as robust as it could be, while providing the pilot with optimum visibility. Powered by a 110hp Clerget 9Z, the double bay, sesquiplane machine was armed with a single, synchronised 303-inch Vickers gun. Described by witnesses as being fast and agile, it is a great pity that no actual performance figures survive. Flown by one or two RNAS pilots on Mudros and Stavros, the A I reportedly made its maiden flight on 15 October 1917. A very real tragedy was that Alcock himself had been forced down and taken prisoner on 30 September 1917, only a fortnight prior to the aircraft's first flight. As to the fate of the A I, sadly, it was ultimately to be 'written-off' as being beyond economic repair following a local crash. John Alcock was of course the same pilot who, when accompanied by navigator Arthur Whitten-Brown in a Vickers Vimy, was to win a lasting place in aviation's annals by making the first ever non-stop transatlantic crossing by aeroplane in mid-1919.
The end of the A.1. It appears to have come off the loser after a tussle with an R.E.8.
Alcock A.1
Alcock A.1
Front View of the Armstrong-Whitworth "Ara", F4971 (320 h.p. A.B.C. Engine).
The clean lines of the Armstrong-Whitworth Ara, this is the first prototype F4971. An excellent performance was ruined by the Dragonfly's unreliability.
The Austin Greyhound

  Under the heading ‘Corps Reconnaissance, Fighter Reconnaissance, Night Reconnaissance’, the RAF Peace Establishment - Type Machines table compiled by the Technical Department and issued on 25 November 1918, lists the Bristol Badger along with the Westland Weasel and Austin Greyhound with Dragonfly engine, as the recommended type to meet these three classes that were then held by the Bristol Fighter. The design was stated to be ‘Ready’ and a competition would be held in February with a decision made by 1 March 1919.
  The Austin Greyhound was another British fighter designed for 1919 that was to be powered by the ABC Dragonfly engine. Construction was underway by June 1918. Under the dual heading of:
   RAF Type III.(a) Short Distance Fighter Reconnaissance
   RAF Type III.(b) Corps Machine for Artillery Work

  The Austin machine’s progress was set out against that of its competitors, the Westland Weasel and Bristol Badger in the Reports of the Design Branch, Technical Department - Aircraft Production as detailed hereunder.

  F/E 12.06.18. Mock-up has been inspected and various improvements suggested. Detail design progressing.
  F/E 26.06.18. Austin (Dragonfly) Contract for three machines. Mock-up of fuselage has been inspected & is being modified in accordance with various suggestions that have been made. 1st Machine. Wooden components of fuselage and planes progressing satisfactorily.
  F/E 21.08.18. Contract for three machines. 1st machine. Erection of fuselage proceeding satisfactorily, and good progress is being made on the components for planes, tail unit and undercarriage, and on preliminary engine installation details.
  F/E 04.09.18. 1st machine No. 4317. Erection of fuselage nearing completion. Guns, ammunition magazines, etc., now being fitted. Planes and tail unit being assembled. Some details of design require modifications for strength.
  F/E 18.09.18. 1st machine No. 4317. Fuselage completely assembled in skeleton with engine bearer, sternpost, tail skid and top section in position. Planes complete in skeleton. Controls ready for fitting. Design passed for experimental flying.
  F/E 02.10.18. 1st machine No. 4317. Machine now completed in skeleton. Controls and petrol tanks fitted. F/E 16.10.18. 1st machine No. 4317. Completed in skeleton. Tail adjusting gear fitted. Work progressing on the fitting of controls and engine cowling.
  F/E 30.10.18. 1st machine No. H4317. Machine is completely erected in skeleton. Alterations to the observer’s controls, camera fitting, etc., are being made and the machine will now be dismantled for covering.
  F/E 13.11.18. 1st machine No. H4317. Machine has been dismantled for covering. Alterations to observer’s controls, camera, fittings, etc., are now in hand.
  F/E 27.11.18. 1st machine No. H4317. Machine had been completely erected in skeleton and is now dismantled for covering. The wind screen is being altered to give the pilot better protection and easier access to the guns.
  F/E 11.12.18. 1st machine No. H4317. Machine completed in skeleton and being covered. Petrol and oil tanks fitted and controls being connected up.
  Period 12-31.12.18. 1st machine No. H4317. Engine had been delivered, and machine is ready to commence flying trials as soon as engine installation is complete.
  Month ending 31.01.19. 1st machine No. H4317. Machine complete and ready for maker’s flying trials which will take place immediately.

  The machine that emerged was a sleek looking two-bay biplane designed by J. Kenworthy who had previously worked for the Royal Aircraft Factory on their design staff. The Greyhound had two synchronised Vickers guns for the pilot with 1,700 rounds of ammunition, and the observer/gunner had a Lewis gun on a Scarff ring in the rear cockpit. The rear fuselage was shaped to give the observer a good field of fire. The two cockpits were placed close to each other so that communication between the crew would be easy.
  The machine was of conventional wooden and wire braced construction with fabric covering. The wings were unequal in chord. The centre-section trailing edge was cut away which, with the narrower chord of the lower wing gave the pilot a good view. The fin and rudder bore traces of Kenworthy’s RAF influences resembling that originally designed for the S.E.5. Approximately equal fin area was carried above and beneath the fuselage.
  The engine was covered by a conical cowl with the engine cylinders exposed. The shape of the cowling was preserved by fairings to the rear of the observer’s cockpit where it blended into the rectangular structure of the fuselage.
  By the time the Greyhound was designed, the heights that aircraft were operating at required the carrying of oxygen and the Greyhound had this together with electrical heating for crew suits, camera and wireless equipment. Dual control was provided.
  The first prototype, H4317, was flown to Martlesham Heath on 15 May 1919. The official tests were not conducted until August, however, being aware of the problems with the Dragonfly engine, this was probably the reason for the delay. While performance proved good, the Greyhound was doomed by the choice of the Dragonfly engine.
  The second prototype, H4318, was received at Martlesham Heath on 11 October 1919, and up to that time had 9 hours 35 minutes flying time. From the aircraft's Log Book it appeared that no wing adjustment had been carried out. RAE Report No. K.1611 was made on the condition of H4218, the second prototype, after 24 hours 25 minutes flying, including the flying at Martlesham. From external examination of the wings, it appeared that they should be stripped. This was carried out and the following defects were found:

  (a). Nine long main ribs were broken, mostly through the flanges.
  (b). Six of the smaller ribs in front of the ailerons were broken in the same way.
  (c). Some of the end compression ribs were warped badly, the packing blocks were loose in several places throughout the wings.
Centre Section:
  (a). The trailing edge had a piece about ten inches long completely broken out.
  (b). Both end ribs were bowed badly.
  (c). The centre main rib was broken at the rear end. In any case, the attachment of this rib was found to be very unsatisfactory.
  (d). Rib flanges and packing blocks had come unglued in several places.
Fuselage and Tail:
  Examination showed that the fuselage and tail were in good condition and no adjustments were required.

  The ribs were found to been extremely light throughout, the flanges being only connected by vertical struts, no oblique struts being fitted between the spars. The distance between the spars in the Greyhound is 41” against 36” in the D.H. 9. and the ribs of the latter are very much stronger and stiffer.
  The end ribs of the centre section were both bowed inwards badly. These ribs were also light and did not appear strong enough to take the loads. They were stiffened by light stringers that had little effect in preventing bowing. This criticism was also applied to the end ribs of the wings to some extent although they were solidly made. They are, however, quite unsupported over the 41” span except by light stringers, and they should certainly be stiffened by oblique struts if not replaced by a box rib. It is quite possible that a box rib could be designed to weigh little more than the present rib with satisfactory supporting struts.
  The compression ribs and spars were in good condition and despite the broken ribs, the internal bracing of the wings did not require any adjustments.
  While the fuselage and tail were in good condition it was noted that the machine had only done 24 1/2 hours.
  The rudder bar had been strengthened but was again found to have buckled and was further strengthened by replacing the 20 SWG bar to 16 SWG. The report concluded by noting that the ribs were being strengthened by the addition of struts and the end ribs were being stiffened.
  The third aircraft, H4319 had a slightly different fin and rudder as well a revised fuel system.
  The Austin Company proposed a mail-carrying version of the Greyhound. The pilot’s cockpit was to be moved back and a mail compartment constructed forward. Fuel capacity was increased to 91 gallons to give it a good range. The idea did not progress beyond a paper project.
  H4318 survived at least until June 1922, when it was flying at the RAE, making its last recorded flight on the 12th of that month.

Austin Greyhound Specifications
Source 1 2
Span top 39 ft 39 ft
Span bottom 36 ft 7 in 36 ft 7 in
Chord top 6 ft 4.8 in -
Chord bottom 4 ft 3 in -
Length - 26 ft 8 1/2 in
Gap 4ft 11 7/8in -
Height 10 ft 4 in -
Span tailplane 12 ft 9.5 in -
Wing & Aileron Area ft2 400 400
Aileron Area Top, ft2 29.6 -
Aileron Area bottom, ft2 15.6 -
Aileron Area total, ft2 45.2 -
Tail Area, ft2 47 -
Elevator Area, ft2 19.8 -
Rudder Area, ft2 9.9 -
Fin top Area, ft2 2.76 -
Fin bottom Area, ft2 2.3 -
Empty Wt, lbs 2,050 -
Gross Wt, lbs 3,090 -
Petrol, gallons 66 -
Oil, gallons 8 -
10,000 ft 11 min 10 min 50
15,000 ft - 19 min 40
Endurance - 3 hrs
Landing speed, mpt 45 -
Speed at 6,500 ft - 129
Speed at 10,000 ft 130 126
Speed at 15,000 ft - 121
Service ceiling, ft - 19,000 ft
Engine 320-hp Dragonfly.
  1. Jane’s All the World’s Aircraft 1919.
  2. J.M. Bruce data.
Austin Greyhound H.4317
Austin Greyhound H.4318
Austin Greyhound H.4319
Compromised by its Dragonfly engine, the Austin Greyhound, whose first prototype is shown here, might well otherwise have been selected to replace the Bristol Fighter.
The first Austin Greyhound H4317.
Greyhound H4317 at Martlesham Heath on 15 May 1919. The rear view shows the tapered rear fuselage to give the gunner a good field of fire.
The first Austin Greyhound, H4317, photographed at Martlesham Heath. Three prototypes were built, the second, H4318, surviving until mid-1922.
The Second Greyhound H4318.
The third Greyhound, H4319, with modified fin.
Austin drawing of the proposed mail-plane version of the Greyhound.
Austin "Greyhound"
Austin "Greyhound"
Austin "Greyhound"
The second prototype Avro 530 two-seat fighter.
A two-seat fighter by Avro, the Type 530 was designed in 1916 as a competitor for the Bristol F.2A, but, when flown, did not afford a sufficient advance.
The Avro Type 533 Manchester I, F3493, with the ill-fated Dragonfly I engines, the second prototype to fly.
The Avro Manchester was the end of the line of a series of twin-engine Avro prototypes that started with the 523 Pike of 1915. The Dragonfly was its proposed engine. F3493.
B.A.T. F.K.22
B.A.T. F.K.22
B.A.T. F.K.22.2
B.A.T. F.K.22.2
BAT Basilisk. F2906 crashed after catching fire in flight casing the death of the BAT test pilot Peter Leigh. The wide undercarriage was a characteristic BAT feature.
Boulton & Paul's Bourges bomber proved to be a magnificent machine capable of being looped.
Bristol Fighter at Bickendorf aerodrome outside Cologne, post-Armistice. The Bristol Fighter was the main user of the Arab. This version was to be used in the reconnaissance role.
The Arab engine installation in a Bristol Fighter.
Standard Arab engine mounting in a Bristol Fighter.
The Bristol Scout F & F.1

  In April 1917 the RFC Technical Department recorded: Approved and put forward for manufacture.
  The 200 h.p. Engine from Engine Patents Ltd., for which the British and Colonial Aircraft Co. are designing a single seater fighter (for six of which machines they have an experimental order) is not likely to come forward for a few months. The matter was discussed with Captain Barnwell on Friday and will be considered by the Technical Department Committee on the 26th instant. It would seem desirable that the firm should complete the design on which they have started, but for the purpose of utilising the geared Hispano Engine (Pousse type), as this engine is one of few types which should be available in quantities by the end of the year and it is therefore important that machines should be designed to make the best use of its power.
  The aircraft being discussed can only be the Bristol Scout E. This was a single-seat scout designed by Frank Barnwell for the new 200-hp water-cooled radial engine, the Cruciform, designed by Harry R Ricardo and Frank B Halford. In 1915 Harry Ricardo set up the Engine Patents Co that developed the engine that powered the first successful British tank, the Mk.V. In 1917 Ricardo joined the new engine research facility at the Department of Military Aeronautics. The proposed Scout E would have had the engine mounted behind a circular radiator. In the event the engine was not completed and Barnwell abandoned the design.
  In June 1917 Barnwell began work on another single-seat scout intended to take the 200-hp Hispano-Suiza engine but this was changed to the new Sunbeam Arab engine, most probably due to the Hispano-Suizas being in high demand for the S.E.5a then in mass production. Newly constructed S.E.5a fighters were going into storage as there were not enough engines to power them. The Arab had the same output as the Hispano-Suiza and was also a V-eight and so was thought to be a good alternative. Contract No.A.S.3423 was placed for six machines - B3989 - B3994. An early report stated that machine had been inspected at the works and detail of construction found satisfactory.
  The Scout F emerged as a very clean biplane that would not have looked out of place on a 1920’s aerodrome, mainly due Barnwell’s decision to install an underslung radiator between the undercarriage legs that, with the nose spinner, gave the machine a streamline appearance. In a period where most liquid-cooled aero-engines had the radiator mounted immediately behind the airscrew, Barnwell’s innovation was a revolutionary break from contemporary practice enabling him to give a clean aerodynamic entry to the machine.
  A report in connection with the installation of a Sunbeam ‘Arab' in a Scout F Machine noted that the installation of this engine is now complete and the machine has been delivered to the Acceptance Park at Patchway. However, the cowling was criticised. It was constructed in three parts and fastened together by means of bolts and butterfly nuts. The camshaft housings are not cowled in. No doors have been provided in the cowling for quickly getting to the magnetos and the carburetter; both these were asked for when the installation was being discussed with the representatives of the firm. In order to get at the magnetos it is now necessary to remove one of the sections of the cowling.
  The wing bracing was characterised by a centre section and N interplane struts. The wings were of unequal span and chord. Oliver Stewart recorded that the wide gap together with the pointed nose gave the pilot an excellent outlook. The upper wing was in three pieces and both wings were installed without dihedral. Ailerons were fitted to the upper wing only. The interplane and centre-section struts were of N shape. Structurally the machine was a conventional wood and wire-braced girder structure aft with the front portion of the fuselage a ply covered box girder. Unfortunately, the twin Vickers guns were mounted externally on top of the fuselage spoiling the clean aerodynamic lines of the Scout F. Given the limited size of the fuselage there was probably no other option open to Barnwell than to position the guns here. A ring and bead sight was fitted.
  A visit to the British and Colonial Aeroplane factory on 17 September 1917, resulted in the following report on the single-seater scout 200 H.P. Arab Sunbeam.
  The machine is very similar in form to the S.E.5, the fuselage being about the same width, but rather shorter.
  The planes are arranged in the same position, the trailing edge of the upper plane being a foot above the pilot’s head, with the centre section cut away. The trailing edge of the lower plane is in a line with the pilot’s body.
  There is a forward stager and a dihedral on the planes, which are rigged with one bay of struts, the struts leaning slightly outwards towards the top.
  The tail plane is of steel tubular construction, strengthened with wooden ribs; it is adjustable, but not from the pilot’s seat.
  The rudder and fin are of the same shape and construction as those on the B and C Monoplane.
  The undercarriage is of the usual V type.
  The armament consists of two Vickers Guns firing through the propeller, arranged to that they feed from the centre of the machine. A Lewis gun can be fitted to the top plane as in the S.E.5.
  The visibility from this machine is very good to the rear and above. The field of view forward and upwards is hindered by the top plane.
  The fuselage and wings have so far not been covered. No instruments or engine controls are yet fitted, as the engine has not arrived.
  The rudder bar on this machine is of the same pattern as that fitted on the B & C Monoplane, and is of an unsuitable type for a machine of this kind, as it has no definite stops to prevent the pilot’s foot moving along or slipping off the end of the bar. This bar should be redesigned with the usual stops and foot straps.
  A report in December 1917, noted that the firm had been visited and the first machine has been inspected. Repairs to engine bearers have been inspected, and a new oil tank to give gravity feed is being fitted. Machine will then be sent to Martlesham.
  The following reports of the Controller, Technical Department, chart the construction progress of the machine. The Scout F was listed under the heading of ‘Experimental Machines Embodying Features of General Benefit to Aeronautics.’

  F/E 23.01.18. Bristol Type F. 200 hp Sunbeam. Contract for 6 machines. 1st machine should have flown to Martlesham on 22.01.18 for tests. Oil tanks giving gravity feed has been fitted.
  F/E 06.03.18.
   1st machine. Undergoing tests at Martlesham.
   2nd machine. Undergoing maker’s trials.
   3rd machine. Being prepared to take Brazil Streaker experimental engine for flying tests of the engine.
  F/E 20.03.18.
   1st machine. Undergoing tests at Martlesham.
   2nd machine. Now ready for despatch from makers.
   3rd machine. Being prepared to take experimental Brazil Straker engine for flying tests of engine.
  F/E 03.04.18.
   1st machine. Tests at Martlesham complete.
   2nd machine. Delivered to R.A.F. for trials.
   3rd machine. Ready for installation of Brazil Straker engine.
  F/E 01.05.18.
   2nd machine. Undergoing trials at R.A.E.
   3rd machine. Ready for installation of Brazil Straker engine.

  B3989 with Arab engine was the first to be subject to testing and the Aeroplane Data Book recorded that the machine had the following “Peculiarities of Design”: -
  On this machine the interplane struts are built up of three strips of spruce glued together, the grain running from end to end of the strut in each piece. At each end of the strut for a length of about nine inches the centre spruce strip is replaced by three-ply ash. A cross strut takes the place of more usual stagger wired, the three struts being secured at junction points where the two sides of the fittings are riveted through the strut; ash bushes are inserted to take the riveting compression. The whole length of the strut is wrapped with glued fabric. The universal fork joints of the main lift and anti-lift wires are located inside the planes to diminish head resistance. Twin spars are fitted in the top planes which are deeply spindled out. On the inner faces small distance pieces are fitted between spars at each rib, and more substantial pieces at each compression rib and at the inner end of wing. At the joint between the centre section and the top planes the spars are reinforced by steel fittings drilled to take fixing bolts. The radiator is fitted underneath the fuselage, just forward of the pilot’s seat, and there is a small reservoir above the engine.
  The Aeroplane Experimental Station reported in March 1918 that preliminary trials with a fast revving propeller had been carried out and show that with a similar load to an S.E.5 (with “Viper” engine) the Bristol Scout does 125 miles an hour at 15,000 feet and reaches that height in 13.7 minutes. This beats the S.E.5 by 5 miles an hour and 7 minutes. It should be noted that the difference in performance must be largely due to the difference in engine revolutions (about 240), and may be slightly effected by the fact that the S.E.5 was tested with a Lewis Gun mounted on the top plane, while in the Bristol Scout the Lewis Gun was merely tied to the fuselage.
  As noted above the Scout F could have a Lewis Gun mounted in the same fashion as the S.E.5a and this test may have been to determine its performance with a full armament of three machine guns. With the two Vickers machine guns it would have given approximately the same load as that of the S.E.5a.
  Test results of the Scout F compared with the S.E.5a and Sopwith Snipe are given in the table:
  Report M.185A looked at the effect of the spinner on the performance of the Scout. B3990 was the subject aircraft for the trial. The trials were carried out with the spinner fitted, then without the spinner for two trials, and again with the spinner. The results were tabulated as above:
  The load carried was:
   Pilot 180 lbs
   2 Vickers and 1 Lewis guns 86 lbs
   Deadweight 10 lbs
276 lbs
  Airscrew details were:
   Type: D.R.P. 3041
   Weight of spinner 8 lbs
   Diameter of spinner at base 21 5/8 in.
   Depth of spinner from geometrical apex of cone to base 14 1/4 in.

  It was found that the performance was improved by the use of the spinner by 100 feet per minute in rate of climb (1 1/2 minutes less in time to 15,000 feet) and by 4 m.p.h. in speed at 15,000 feet.
  B3990 went to Martlesham Heath on 30 January 1918, but official trials were delayed by engine troubles and had to await the arrival of a new engine from the Sunbeam Company. The tests at Martlesham Heath had included the comparative tests with and without the spinner as noted above. The Cosmos Engineering Co Ltd advertisements proudly acclaimed A Bristol Scout fitted with a 'Mercury’ engine climbed 10,000 feet in 5 mins. 25 secs., & 20,000 feet in 16 mins. 15 secs., speed at 10,000 feet 143 M.P.H. Official corrected barographfigures. This constituting two British records. B3990 was still at the RAE Farnborough in July 1919. By then the engine bearers had to be reinforced with mild-steel channel strips as they were in a bad condition
  Oliver Stewart found that the little Bristol F was a pleasure to fly and could be made to do ordinary aerobatics. Its Arab engine, designed by Coatalen the car engine designer, was smooth running through most of its range, but had periods when it vibrated violently. There was a crankshaft and airscrew resonance which more than once caused Arab-engined aircraft to shed their propellers while in flight. A Stewart recorded that the control qualities of the machine were between those of the Sopwith Camel and the S.E.5a. The elevator was not so sensitive as that of the Camel, but it was probably more powerful than that of the S.E.5. And in general, the aeroplane felt handier than the S.E.5, but less handy than the Camel.
  Capt Reginald M Charley had served with No.54 Squadron in France before he was sent to Orfordness as a test pilot. On arrival he found his friend Capt Oliver Stewart who had also just arrived the previous evening. The two were to fly the many various machines that came through the experimental centre. Charley made pertinent comments on the aircraft he flew in his log book. He not only recorded serial numbers but engines fitted and the time of the flight. He flew the usual Camel, S.E.5a and Dolphin types as well as experimental types such as the Sopwith Bulldog and Vickers Vampire, all recorded with his impressions. After his first flight in B3990 on 7 April 1918, Charley was enamoured with the little Bristol Scout. In a later letter he wrote that he had flown the most wonderful scout in the world: it flew at 140 mph and Climbed to 10000 ft in seven minutes or under. Charley’s logbook entries covering the Bristol B3990 are listed below: -
  7.04.18. Time 2.45 PM. 50 min, 14,000 ft. [P]erfectly super wonderful machine; colossal performance: lovely clouds.
  3.05.18. Time 9.35 AM. 90 min, 22,000 ft. [H]eight record to date; felt very dizzy; fought B.F at 18,000ft. fine machine.
  15.05.18. Time 9.15 AM. 25 min, 10,000 ft. [T]hrough several layers of cloud; engine not running very well.
  15.05.18. Time 9.15 AM. 20 min, 6,000 ft. [W]ith new radiator shutter & seat: more comfortable to fly but engine bad.
  30.05.18.Time 10.15 AM. 35 min, 15,000 ft. [M]achine is really fine engine now O.K. & machine wonderful 10000 ft. in 8 1/2 mins. 112 m.p.h. at ground.
  31.05.18. Time 10.0 AM. 40 min, 10,000 ft. [E]ngine gets rather hot in hot weather; radiator shutter does not keep it warm.
  4.06.18.Time 3.10 PM. 40 min, 10,000 ft. [G]ets hot if climbed too steeply; air press, went dud; machine otherwise O.K.
  6.06.18. Time 10.15 AM. 60 min, 20,000 ft. 20,000ft. in 20 mins, engine gets very cold coming down. 145 m.p.h. near ground.
  10.06.18. Time 9.20 AM. 50 min, 10,000 ft. [O]il pressure varied a great deal but engine kept very cool.
  13.06.18 Time 18.10 AM. 55 min, 10,000 ft. O.S. on Camel & I fought A.E.3. I went up through a lot of cloud.
  13.06.18.Time 3.55 PM. 35 min, 8,000 ft. O.S., Duncan & I fought A.E.3 & it had not got a hope; very bumpy.
  14.06.18. Time 10.00 AM. 55 min, 10,000 ft. [T]hrough 4000 ft. of solid cloud; made a hoppy landing.
  17.06.18. Time 11.40 AM. 20 min, 11,000 ft. [B]oth guns gave stoppages I could not correct.
  26.06.18. Time 3.15 PM 5 min, 1200 ft. [T]o show General how it climbed, but engine conked & I had to land.
  26.06.18.Time 3.40 PM. 25 min; 10,000 ft. [P]ut machine to full test & it went well; went through clouds.
  26.09.18. Time 10.00 AM. 30 min, 12,000 ft. [E]ngine going very well & machine very nice to fly pitot dud but made good landing.
  27.09.18.Time 2.40 PM. 50 min, 10,000 ft. [F]ive machines to attack a Flying Boat which did not turn up. [W]e fought an Aldebungh (illegible) engine.
  9.12.18. Time 20 min, 2000 ft. [B]est flight I had for a long time; doing 140 m.p.h. zoomed up almost vertical.
  23.01.19. Time 40 min, 2,500 ft. [A]wful job to get it started; engine was not so good, one mag cut out altogether
  06.02.19. Time 15 min, 2,000 ft. Rev. Howard was over. I flew down over Crag Farm & Renie & Mrs Madeles saw me.
  25.02.19. Time 50 min, 4,000 ft. MacKerrow was in F.E. and took pictures of me in many positions with aerial camera; fine results.
  10.05.19. Time 15 min, 1,000 ft. [T]est flight before it was sent to Farnborough; lovely machine, going fine.

  On the occasion he flew B3990 to 22,000 feet indicated, it is not surprising he felt the effects of the lack of oxygen. On 25 May he took B3990 up again for another test. The machine had new radiator shutters fitted and a more comfortable pilot’s seat, but the engine’s performance had not improved. On 30th the Arab was running well and he had a good flight in the machine. The next day he found that the Scout F’s engine tended to overheat below 10,000 feet, the radiator shutters having failed to maintain the required temperature. Charley wrote that he and Stewart would engage in using other aircraft that entered their realm as target practice and he records the Scout F was flown against the Bristol Fighter and the luckless R.A.F. A.E.3. Stewart and Charley would ‘scrap’, one flying a Camel, the other the Scout F. Although he enjoyed the trouble-free Rolls-Royce engine of the Martinsyde F.3, he still stated his preference for the Scout F. On 26 June Charley was to demonstrate the Scout F before visiting dignitaries. The Arab engine cut out shortly after take-off and Charley had to land again. The trouble was quickly rectified and he was able to demonstrate the type’s performance when the Arab was behaving as it should.
  The 14-cylinder twin-row Mercury radial from the Brazil, Straker Co, that was coming together under the eye of Roy Fedden, was the engine mentioned in the above Controller’s reports. The engine had been ready for some time for bench testing but this had been held up while the company was reorganised and refinanced as the Cosmos Engineering Co Ltd. A Mercury was finally installed in the third machine, B3991. With this engine the designation was changed to Scout F.1. The fourth airframe was used for structural testing at Farnborough, the results being published in November 1918. Only the first three machines were flown. As mentioned above the Mercury engine was being thought of as a suitable engine for the Scout in March 1918 but the long development period and the changes in the company led to its first test flight in the Scout F.1 being made on 6 September 1918.
  In order to streamline the radial engine a circular cowling through which the fourteen-cylinder heads protruded was installed. Although the performance was improved considerably the handling qualities were adversely affected. Capt Cyril F Uwins was well known to the Company, due to his ferrying Bristol Fighters to France. At the Company’s request he was seconded to the Company as a test pilot, and carried out the second flight on the Mercury powered scout, his first prototype for the British and Colonial Aeroplane Co on 26 October 1918, the day after he joined the Company. The following performance achieved at Farnborough was, for its time, remarkable:
  Climb to
   10,000 ft - 5 min 25
   20,000 ft - 16 min 15
  Speed at 10,000 ft - 143 mph.

  Notwithstanding these results, the F.1 was too late.The Cosmos Company had decided to concentrate on their nine-cylinder Jupiter radial engine and the Mercury was shelved. The Mercury would have needed more time as it only delivered its rated horse-power for short periods and would not have passed the official testing regime. It only ever flew in the Scout F.1. Soon after the Armistice the Air Ministry cancelled the order for the 200 Mercury engines, but testing continued into 1919.
  Writing in 1968, Eugene R McDonald stated that when he arrived at the Armament Experimental Station (Grahame White’s old aerodrome) he was, intrigued to find a machine I did not know, it appears to be smaller than an SE5, had a deep body and a large boss on the prop.
  This was the Bristol Arab, powered by the Sunbeam Arab engine. I was delighted with the performance and found it faster than any SE5 I had ever flown. (This was not an official flight or test). I have no proof of the following statement. I merely understood that the Sunbeam Arab engine had been produced in 1917, and was intended for the Bristol two-seater. It was found that the performance of the 2 seater fighter with the new engine was no better than that given by the existing engine above 16,000 feet, and the engine was discarded. I don’t know who put the Sunbeam Arab Engine in the single seater I flew, but I think it would have been an asset in 1918, had we been able to use it?
  The Scout F had excellent handling qualities and was superior to the S.E.5a in some areas. Keith Knox Muspratt had the opportunity to fly the new Bristol Scout in February 1918, the nicest thing I have ever flown. It was remembered as a great machine let down by its Sunbeam Arab engine. Oliver Stewart summed it up best: - The Bristol F was a machine of quality, and although it never came into general use... those who flew it will remember it with interest, and a certain amount of admiration. It was not a prodigy, but it was a pleasant aeroplane with many good qualities.

Bristol Scout (S.E.5 load) "Viper" S.E.5 Bristol Scout (Snipe Load) Snipe
Load lbs Load lbs Load lbs Load lbs
   Pilot 180 Pilot 180 Pilot 180 Pilot 180
   2 V & 1 L guns 86 1 V & 1 L gun 51 2 V & 1 L guns 86 2 V & 1 L guns 86
   Deadweight 10 Deadweight 55 Deadweight 233 Deadweight 263
   - - - - Petrol 34 gls 245 Petrol 26 gls & Oil 6 gls 245
   Oil 3 gls 30
   Total Load 774 Total Load 774
   Total Weight of machine 1987 Total Weight of machine 1985 Total Weight of machine 2210 Total Weight of
Machine 1992
Height Time RofC RPM Time RofC RPM Time RofC RPM Time RofC RPM
5,000 3.3 1325 2010 4.5 960 1785 3.9 1110 2020 3.6 1165 1220
10,000 7.7 1000 2010 10.8 665 1780 9.25 795 2015 8.75 760 1195
15,000 13.7 665 2000 20.75 370 1770 17.25 475 1995 17.6 400 1160
19,000 - - - - - - 29.2 220 1980 34.4 130 1105
Service ceiling 23,500 ft Service Ceiling 19,500 ft Service ceiling 21,000 ft Service Ceiling 19,000 ft
Height Speed in mph RPM Speed in mph RPM Speed in mph RPM Speed in mph RPM
10.000 - - - - 128 1/2 mph 2265 124 mph 1330
15,000 125 mph 2225 120 mph 1880 117 1/2 mph 2150 113 1/2 mph 1255
Propeller D.R.P.3041 This load is equivalent to the S.E.5 load on the assumption that the Bristol Scout would carry only one Vickers gun & the same amount of petrol as the S.E.5 Propeller A.B.662 P.1800 D.2400 Propeller D.R.P.3041 P.2750 D.2800 Propeller L/4040 P.2490 D.2780

Bristol Scout F Climb Trials
With Spinner Without Spinner
Height Time RofC RPM ASI Time RofC RPM ASI
5,000 3.3 1325 2020 73 3.6 1220 2000 73
12,000 7.7 1000 2010 71 8.4 895 1990 71
15,000 13.7 665 2000 68 15.4 570 1975 67
Height Speed RPM Speed RPM
15000 125 2225 121 2180
Report M.185A looked at the effect of the spinner on the performance of the Scout. B3990 was the subject aircraft for the trial. The trials were carried out with the spinner fitted, then without the spinner for two trials, and again with the spinner. The results were tabulated as above.

Bristol Scout F & F.1 Specifications
Source 1.F 2.F 3.F 4.F 6.F 5.F.1 4. F.1
Span top 29 ft 6 in 29 ft 7 1/2 in - 29 ft 7 1/2 in 29 ft 6 in 29 ft 7% in
Span Bottom 26 ft 2 in 26 ft 2 in - 26 ft 2 in 26 ft 2 in 26 ft 2 in
Chord top 5 ft 7 in 5 ft 7 in - 5 ft 7 in 5 ft 7 in 5 ft 7 in
Chord Bottom 4 ft 11 in 4 ft 11 in - 4 ft 11 in 4 ft 11 in 4 ft 11 in
Length 20 ft 10 in - - 20 ft 10 in 20 ft 10 in - 20 ft
Height - - - 8 ft 4 in 8 ft 4 in - 8 ft 4 in
Incidence 1° - - 1° - - 1°
Incidence top - Nil - 0° - - 0°
  “ bottom - 1° 1’ - - - - -
Dihedral - Nil - - - - -
Gap 5 ft 1 in 4 ft 9 1/4 in - - 5 ft 1 in - -
Stagger 2 ft 1 in 2 ft 0 in - - - - -
Tailplane span - 10 ft 4 1/4 in - 10 ft 6 in 10 ft 6 in - 10 ft 6 in
Airscrew dia. - - - 9 ft 2 in 9 ft 2 in - 9 ft 2 in
Wings top 150 - - 150 - - 150
Bottom 110 - - 110 - - 110
Total 260 259 - 260 260 - 260
Ailerons 30.5 16.6 - 30.5 30 - 30.5
Tailplane 15 14 - 15 15 - 15
Elevators 14.5 14.5 - 14.5 14.5 - 14.5
Fin 4.1 3.5 - 4.1 4.1 - 4.1
Rudder 5.3 - - 5.3 5 - 5.3
Empty - - 1,436 1,436 1,300 1,365 -
Fuel & Oil - - 275 275 - 213 -
Military load 270 - 96 319 - 42 -
Crew - - 180 180 - 180 -
Loaded 2,100 - 1,987 2,210 2,100 1,800 2,260
Fuel total 32 - - - 32 - -
main tank - 29 1/2 - 29 1/2 - - -
service tank - 3 - 3 - - -
Oil 5 - - 5 5 - -
Water header tank - 1 1/2 - 1 1/2 - -
Ground level 138 - - 138 138 - 145
at 5,000 ft - - - 135 135 - -
at 6,500 ft - - - - - 143 -
at 10,000 ft 128 - - 128.5 128 136 -
at 15,000 ft - - 125 117.5 - - -
Landing 49 - - - 49 - -
5,000 ft - - - - 3.7 min - -
6,500 ft - - 4.5 min 5 min 20 - - -
10,000 ft 8.5 min - 7.7 min 9 min 20 8.5 min 5.5 5 min 25
15,000 ft 16.0 min - 13.7 min 17 min 20 16 min 9.9 -
20,000 ft - - - - - - 16 min 15
Max Height reached in ft - - - - - 23,760 -
Ceiling in ft - - 23,500 - - - -
Engine Sunbeam Arab 200 Sunbeam Arab Arab Sunbeam 215 BHP 200 h.p. Sunbeam Arab II 200-hp Sunbeam Arab Mercury 347-hp Cosmos Mercury
  1. “Milestones - The Bristol Machines,” Flight, 23.01.1919. P.100.
  2. Aeroplane Data Book - B3989.
  3. Chart: “Performances of British Aeroplanes March-April-May 1918,” issued by Technical Dept A.P Data from report M.185 of March 1918. Copy in TNA AIR1/708/27/11/03.
  4. J.M. Bruce data.
  5. Chart: “Notable Performances of British Aeroplanes - Single-seat Machines.” Tested at Farnborough in March 1919. Copy in RAF Museum, J.M. Bruce Collection Box 26.
  6. Janes Al the World’s Aircraft 1919.
Bristol Scout F B3989
Bristol Scout F B3990
Bristol Scout F.1 B3991
The first Bristol Scout F, B3989, with the unpopular Sunbeam Arab engine; the humped fairing over the engine covers the water header tank. The large scoop for the radiator under the forward fuselage is well shown.
The second Scout F B3990
The second Scout F B3990.
Further views of B3990.
Bristol Scout F.1, B.3991, photographed at Farnborough.
Cosmos Mercury 14-cylinder radial engine changed the lines of the Bristol Scout F.1.
Three-quarter Rear View of the Bristol type F.1., Single-seat Fighter. (Fitted with a "Mercury" Cosmos engine of 315 h.p.)
The only Bristol Scout F.1 built, B3991, with the Cosmos Mercury radial engine; note that ailerons are only fitted on the upper wing.
A Bristol fighting scout fitted with a 350 h.p. A.B.C. air-cooled engine designed by Mr. Bradshaw.
A 1919 Advertisement extolling the merits of the Cosmos engine.
Close-up of the Mercury in the Scout F.1.
Three-view of the F.1 from the Aeroplane Data Book.
Bristol Scout F
Bristol Scout F
The Bristol F.2C Badger

  In October 1917 Frank Barnwell proposed a new two-seat fighter-reconnaissance aircraft to replace the Bristol F.2B Fighter. This was designated F.2C. The designation had been used earlier to denote a version of the Rolls-Royce Falcon F.2B having improved engine installation, landing gear and tail unit. As this would have meant a major redesign of jigs that were already in use for mass production, the idea was abandoned. This new aircraft had been designed for rapid production.
  The proposed biplane had unstaggered two-bay wings with the pilot and gunner/observer close together and mounted high up to give them the best possible view. The pilot’s head projected through a hole in the centre-section of the upper wing. Twin synchronised Vickers guns were provided for the pilot and the gunner had two pillar-mounted Lewis guns, one forward and one facing aft. The proposed powerplant was the 260-hp Salmson nine-cylinder radial. By the end of November, it was evident that the Salmson engine would not be available and the design was revised to use the 230-hp Bentley B.R.2 rotary engine. Neither engine had the required power to permit overloads without loss of performance and were rejected.
  The new A.B.C Dragonfly radial seemed to be the solution with its promise of 320-hp. Barnwell drew up a new design around this engine that he submitted in April 1918.
  This emerged as a single bay biplane with staggered wings of unequal span. Its clean appearance showed it had many features derived from the Scout F. Although a fuselage mock-up was built and the layout agreed with RAF officers, it was September 1918 before a contract was raised. By then the Dragonfly had shown its intractability and could only be run for some 17 hours before it broke a crankshaft.
  The Badger was proposed for the RAF as:
   Type IIIa Short distance fighter reconnaissance machine
   Type IIIb Corps machine for artillery work.
   Type IVb Long distance photographic machine.
  It was in competition with the Austin Greyhound and Westland Weasel. By June it was decided that the Type IVb requirements should be met by twin-engine machines.
  The following Reports of the Technical Department, Aircraft Production, Design Branch, give the following sequence of events relating to the construction of the Bristol design. (One additional report is inserted where it fits the chronological sequence as noted).
  F/E 01.05.18. Bristol, Dragonfly. Contract for three machines. Design proceeding.
  F/E 12.06.18. The mock-up has been inspected and will be ready for final inspection next week. Detail design proceeding.
  F/E 26.06.18. Mock has been inspected and the modifications suggested have been carried out.
   1st machine. Components of fuselage and planes well in hand. F/E 07.08.18. Mock has been inspected and the modifications suggested are been carried out.
   1st machine. No. F3495. Components of fuselage and main planes well in hand.
  F/E 21.08.18. Bristol Badger. (First use of the name).
   1st machine. No. F3495. Fuselage being erected. Planes, tail unit and undercarriage components well in hand.
  F/E 04.09.18.
   1st machine No. F3495. Fuselage being erected and planes being assembled. Details of engine installation in hand.
  F/E 18.09.18.
   1st machine No. F3495. Fuselage erected in skeleton. Engine bearer plate has been fitted. Planes ready for assembly. Modifications to main plane structure for strength have been called for.
  F/E 02.10.18.
   1st machine No. F3495. Machine erected in skeleton. Controls and petrol tanks fitted. Engine bearer plate being fitted.
   It has been arranged to fit the Jupiter engine in one of the remaining machines for flying trials of the engine.
  F/E 16.10.18.
   1st machine No. F3495. Fuselage erected in skeleton and is almost ready for covering.
  As it has been arranged for a Jaguar engine to be fitted in one of these machines (Bristol Badger Mk. II) for air trials of the engine, a recommendation has been made that the contract be increased to cover 4 machines of this type.
  W/E 26.10.18. Contract 35A/1122/C994 of 28.09.18 with British & Colonial, Mod No.35A/4653
   Amend contract so as to increase the No. of experimental two-seat tractor aeroplanes to RAF Spec No.30 Br478 and 3B to be supplied from three to four. Three to be fitted with Dragonfly engines as specified in Contract and to be known as Bristol Badger M.1 and the fourth Aeroplane is to be fitted with Bristol Straker Juniper (sic) engine and be known as Bristol Badger Mark.2.
  F/E 14.10.18.
   1st machine No. F3495. Machine is completely erected in skeleton. Certain fittings are being modified and the armament components, which are complete, are now being fitted. When this is done the machine will be dismantled for covering.
   (As it has been arranged to fit a Jaguar engine in one of these machines (Bristol Badger Mk.II) for air trials of the engine, a recommendation has been made that the contract be increased to cover 4 machines.)
  F/E 13.11.18.
   1st machine No. F3495. Machine is completely erected in skeleton. Controls being fitted and armament details are now being completed.
   Design approved for production as regards strength.
F/E 27.11.18.
   1st machine No. F3495. Machine is completely erected in skeleton and ready for covering. Engine controls and armament details complete.
  F/E 11.12.18.
   1st machine No. F3495. Centre section has been covered and erected. Remaining components being covered. Rear portion of engine cowling completed. Petrol system nearly complete.
  Period to 31.12.18.
   1st machine No. F3495. Engine has been delivered and machine is ready to commence flying trials as soon as engine installation is complete.
  Month ending 31.01.19.
   1st machine No. F3495. Machine practically ready for flying. Some slight modification to the petrol system is being effected.

  As described in the chapter on the Scout F, the Cosmos Jupiter nine-cylinder 400-hp radial had become available. Bristol was given a contract for three prototypes, two to be powered by the Dragonfly and one with the Jupiter so that comparison testing could be made. The new aircraft was given the designation F.2C and the name Badger. Serials F3495 to F3497 were allocated to the machines. As the war ended soon thereafter all contracts were quickly terminated but experimental contracts were allowed to continue with the first two Badgers being completed.
  The Badger was a good-looking aeroplane when first rolled out. It had a hemispherical cowling over the engine that left the cylinders exposed. A single bay biplane with swept-back wing panels, the crew were positioned close together, the pilot having the usual synchronised twin Vickers guns and a single Lewis gun for the observer/gunner mounted on a Scarff ring. This mounting was above the upper longerons and had cutaway sides to increase the field of vision of the observer/gunner. According to King a Bristol document indicated that one of the pilot’s guns could be removed when bombs were carried.
  F3945 was taken for its first flight by Cyril Frank Uwins on 4 February 1919. Flt Lt Uwins was seconded from the RAF on 25 October 1918, to the Company as a test pilot, replacing New Zealander Capt Joseph J Hammond who had been killed at Indianapolis while with the British Aviation Mission to the USA. Hammond was on a war bond tour when he crashed his Bristol Fighter after entering a spin. Uwins was formally demobilised on 1 May 1919, and continued to be a test pilot for Bristols. The Badger was the first aircraft he was entirely responsible for. He was to make the first flight of 58 different types of aircraft and became the Chairman of Bristol Aircraft. He passed away on 11 September 1972, at Bath.
  An airlock in the Dragonfly engine caused a forced landing of F3945 on 4 February 1919, in which the landing gear and engine mounting were destroyed. The machine was rebuilt with an improved engine installation with revised cowling to provide more cooling, and a slightly larger rudder but still without a fin, and delivered to the Air Board on 15 February. Although the Dragonfly engine’s problems were finally realised as serious, in September 1919 a Dragonfly powered Badger was undergoing official trials at Martlesham Heath.
  It appears that F3945 was the only Badger to have the Dragonfly engine installed. Owing to the late delivery of the Jupiter engine F3946 did not fly until 24 May 1919, with Uwins as pilot and Barnwell in the observer’s seat. By June this machine was flown without armament and had the rear cockpit partly faired over. A large fin and plain rudder were fitted. Although engine testing was carried out without any trouble the lateral control of the Badger was not satisfactory and the third machine, F3497, was cancelled.
  Barnwell was concerned that the wind tunnel tests of a 1/10 model of the Badger at the National Physics Laboratory had not predicted the lateral instability. He and Leslie Frise designed a slab sided simple aerodynamic flying test-bed using the wings, tail surfaces and landing gear from the cancelled Badger F3947, and a war-surplus 240-hp Siddeley Puma engine. This was initially known as the Badger Experimental, later the Badger X. Registered as K110, later G-EABU, but it had been written off by this date. Although Uwins made a successful flight on 13 May, Barnwell, never a good pilot, nosed it over on 22 May. Although it could be repaired, the Directors of the company decided not to.
  After cancelling the project, the Air Board was impressed enough by the Badger’s performance to order a fourth example under Contract No. 35a/3312/C3844 of 9 November 1918.36 This was J6492, a Badger Mk. II. Originally built with the same rudder as F3496, it was fitted with a horn balanced rudder and park-bench balanced ailerons. Purchased by the government the machine was then loaned to the company for testing the Jupiter engine.
  On Wednesday 15 June 1919, representatives of the press were invited by The Cosmos Engineering Co Ltd to inspect their works and watch a flight of the ungeared 450-hp Cosmos Jupiter Mk.I engine in the Bristol Badger. The Aeroplanes correspondent described how the engine started at the very first attempt, and the machine got away and flew well, very much as one would expect a machine designed by Capt. Barnwell, with 450 h.p. for a total weight of2,800 lbs., to fly.
  Preliminary test figures were:
   Engine revs on ground - 1,550 rpm
   Average revs while climbing at 80 mph - 1,600 rpm
   Climb to 2,000 ft - 1 min 4 sec
   4,000 ft - 2 min 10 sec
   6,000 ft - 2 min 33 sec
   7,000 ft - 4 min 15 sec
  The Aeroplane reported that the engine installation been modified somewhat, the machine guns removed and the passenger’s seat faired in, and the test results given above will doubtless be considerably improved upon.
  J6942 appeared with a variety of engine cowlings, the last being that destined for us on the Handley-Page O/10 passenger liner.
  An April 1920 Report gave the following:
   1st machine F3495 at Martlesham under repair.
   2nd machine J6492 (Jupiter) RAE undergoing repairs to engine.
   3rd machine F3496 at Martlesham under repair.

  F3495 was at the AEE from June 1919 to September 1920.
  F3496 is reported to have crashed, possibly in October 1919.
  J6492 was at the RAE from March 1920 to February 1921.
  On 13 December 1921, J6492 was in flight from the RAE when the propeller suddenly burst, losing a large portion of one blade. The machine was fitted with Jupiter engine No.801/A/26466 at the time. The pilot reported as follows: -
  I left the ground at 14.55 hours, intending to carry out a general test of the engine. I climbed the aeroplane at full throttle at 70 m.p.h. and reached 10.000 feet after 7 min. 15 secs. I continued the climb, with various throttle adjustments and testing the altitude control, to 11,000 feet where I shut off the engine and glided down to 8,000 feet.
  After having thus cooled the engine I tested it to see if it would open up well, which it did without hesitation. Having warmed up the engine slightly, I started to fly level with full throttle to ascertain the full level speed at 8,000 feet. After about 10 seconds level flight (the revs, having reached just over 1600, and the airspeed having passed 105 m.p.h. and still increasing) one blade of the propeller came off at 15.11 hrs. After 16 mins, flight.
  I immediately throttled down, switched off, and glided down to land. I landed at 15.23 hrs. After 28 mins, flight. The vibration of the engine before it could be stopped was exceptionally severe and seriously distorted the fore part of the machine, necessitating the removal of the engine.
  After landing examination showed that the engine had moved back about 3/4 inch after the propeller had failed and then moved back to its near original position. This displacement was indicated by deep bruises in the bulkheads made by the ends of the induction pipes, that had distorted the engine back-plate, smashed the heads of several rivets and buckled the port bottom stay behind the backplate.
  In February 1922 a report was made on modifications that were made to J6492. It had been found “during the inspection made after the propeller had burst in flight that the aeroplane had been passed out as airworthy in a condition that did not meet the requirements originally laid down by the Air Ministry.” The propeller had failed on the second flight the machine made at the R.A.E.
  On examination it was found that the machine had spindled spars and not the solid spars required. As a new propeller had to be designed and made and new wing spars had to be fitted it was decided to make other modifications considered desirable while the opportunity presented.
  These were:
  The laminated and spindled spars were replaced by solid spars. While this increased the weight, the complete redesigning of the wings would have meant scrapping them with all their fittings.
  The standard box-section compression ribs in all planes were replaced by solid ribs.
  The internal bracing wires between the centre-section and the struts were increased in size from 4 B.A. to 2 B.A.
  The pulleys on the lateral control cable on the bottom plane were insufficiently guarded. The ailerons were provided with variable gearing but the pulleys were not provided with any form of adjustment for different gear ratios. When the aircraft arrived at the R.A.E. the pulley brackets were set for one gear-ratio and the cable was attached to the aileron for another. New standard Bristol Fighter pulleys were fitted.
  The RAF Peace Establishment - Type Machines table that was compiled by the Technical Department and issued on 25 November 1918, listed under the heading “Corps Reconnaissance, Fighter Reconnaissance, Night Reconnaissance,” the Bristol Badger along with the Westland Weasel and Austin Greyhound, all with Dragonfly engine as the recommended type to meet these three classes that were then held by the Bristol Fighter. The design was stated to be “Ready” and a competition would be held in February with a decision made by 1 March. Such competition was never held, all three machines remaining only prototypes. The Bristol F.2B continued in service through the 1920s performing the work required by the reduced RAF at home and abroad.
  The Badger did perform experimentally and although unknown today, it deserves to be remembered for its pioneering work as an engine test-bed that helped to bring the Jupiter series of engines into series production. It was struck off charge in October 1923, presumably still at the RAE.

Bristol F.2C Badger Specifications
Source 1 1 1 1 1 2 3
Type F.2C F.2C Badger I Badger II Badger X Badger Badger II
Span 36 ft 5 in 31 ft 5 in 36 ft 9 in 36 ft 9 in 34 ft 2 in - -
Length 6 ft 8 ft 9 in 9 ft 1 in 9 ft 1 in 9 ft - -
Height 6 ft 8 ft 9 in 9 ft 1 in 9 ft 1 in 9 ft - -
Wing Area, ft2 408 348 357 357 340 - -
Empty Wt, lbs - - 1,950 1,950 - - -
Loaded Wt, lbs - - 3,150 3,150 - 2,800 2,800
Speed Max - - 135 142 - - -
Spd at 7,000 ft - - - - - 137 -
Ceiling, ft - - 19,000 20,600 - - -
Climb to 2,000 ft - - - - - - 1 min 04
Climb to 4,000 ft - - - - - - 2 min 10
Climb to 6,000 ft - - - - - - 2 min 33
Climb to 7,000 ft - - - - - - 4 min 15
Engine 260 Salmson 230 B.R.2 Dragonfly Ia 400 Jupiter I 230 Puma Jupiter
1. Barnes, C.H. Bristol Aircraft since 1910, Putnam, UK, 1964.
2 Flight, 26.12.1919. P.1652.
3. J.M. Bruce Data. RAF Museum J.M. Bruce Collection Box 26.
Bristol F.2c Badger II F.3496
Bristol F.2c Badger II J.6492
Bristol F.2c Badger II J.6492 Late
The cowl on the rebuilt F3495 exposed more of the cylinders.
F3496 with Cosmos Jupiter I engine and plain rudder and ailerons.
The Bristol Type 23 F.2C Badger Mark II prototype, F3496, with the Cosmos Jupiter I radial engine; the fixed tail fin has been added, the Vickers gun armament omitted and the rear cockpit faired over.
Badger II J6492 with modified horn-balanced rudder and new fin. The “park-bench” type aileron balances are well shown in this view. The engine was the Cosmos Jupiter I. (via P. Jarrett)
The third Military Badger II J6492 with Cosmos Jupiter I engine.
Badger II J6492 after it was fitted with the 385-hp Bristol Jupiter II engine in a revised polygonal cowling designed for the Handley Page O/10 in 1921.
Badger II J6492 after it was fitted with the 385-hp Bristol Jupiter II engine in a revised polygonal cowling designed for the Handley Page O/10 in 1921.
Badger X at Filton in May 1919.
The slab sided Badger X was undoubtedly one of the plainest looking aircraft ever to take to the skies. (via P. Jarrett).
Bristol F.2C Badger
Bristol F.2C Badger
The Dyott AT "Battleplane"

  George Miller Dyott was a frequent name in the pages of the British journal Flight in the years before the war. Dyott had gained his Royal Aero Club pilot’s certificate on 11 August 1911. He then went to the USA where he flew a Deperdussin monoplane on demonstration flights to a paying public. On his return to the UK, he designed a small monoplane that he had built for him by Hewitt & Blondeau Ltd of Oak Rd, Leagrave, Luton, complete, with the exception of the wings and the motor, for the sum of £225-0-0.
  The monoplane was taken by Dyott to the USA where he did exhibition flying for about six months. The Aeroplane described the arrival of Dyott, fresh from his adventures in North and Central America. His monoplane - a machine of his own design, built a year ago by the Hewlett and Blondeau firm - turned up early one afternoon, crated, and was in the air by three o’clock or thereabout. It described the Dyott Monoplane as looking brand new although it had flown more than two thousand miles and been taken down and reassembled repeatedly; in fact this quality of handiness in knocking down and setting up is one of the main features of the machine. The whole machine could be knocked down and the whole machine would go aboard an ordinary railway truck.
  The Dyott monoplane did away with pulley wheels. All control cables were straight from lever to lever. The only pulley was that of the cabane that carried the top-side tip-connecting cable. The machine gets up very quickly, and flies exceedingly well, with a speed range of 45 to 65 M.p.h. (approx.), although it is pulled only by an ancient 50-h.p. Gnome, and is encumbered with a compass, a clock, a barometer, a revolution indicator, an ingenious mechanism which records every movement of each control. The total weight is about 600 pounds.
  With this machine he regularly entered the pages of the aeronautical journals Flight and The Aeroplane. On the outbreak of war, the machine was impressed by the RNAS as Serial No. 1598.
  And as to the Dyott monoplane that he had left stored when he joined the RNAS? Writing of his experiences in France, Dyott noted that the equipment of the Squadron was always being changed, and we were called to fly all kinds of machines, such as Avros, B.E’s, Moranes, Bleriots, Voisins and heaven know what. Even my little monoplane, which had been through so many vicissitudes both in England and America, was there to join in the variety. The reader will probably recall how this machine figured in several accidents from which it always seemed to emerge none the worse for wear, like Phoenix from the ashes. Prior to the Government purchasing it, the shed in which it was housed was blown down in a wind storm and the roof fell on the machine. When the debris was removed, it was found that, by some miraculous coincidence, no vital part was broken. After being newly recovered and overhauled, it was handed over to the Admiralty in excellent trim. At the end of the year 1915, it was returned to Dover for instructional purposes and in 1916, after three and a half years useful work, it was deleted and burned to make room for more powerful machines. At that date, I doubt if any other aeroplane had ever had such a varied and eventful career as it had.
G. M. Dyott in the cockpit of his Dyott Monoplane at Hendon.
The Dyott as it appeared after being returned from the USA and refurbished. Dyott knew how to advertise.
Dyott monoplane built by Hewlett & Blondeau in 1913.
The Dyott monoplane in RNAS markings as No. 1598.
The cockpit of the Dyott monoplane had a good set of instruments for the time, including a device of his own invention to record control movements.
The Dyott monoplane was of conventional construction and typical of the early monoplanes with the wings supported by cables from an inverted V pylon located at the front of the cockpit. Dyott incorporated several improvements that he had worked out with his experiences in the USA giving exhibitions. The wings were easily removed for ease of transport. The 50-hp Gnome rotary had a partial cowl to prevent oil being sprayed over the pilot.
The Dyott AT "Battleplane"

  It is reported that before the war Dyott had designed a larger twin-engine aircraft that he proposed to use to explore Africa. After the outbreak of war, he joined the RNAS as a Flight Lieutenant. Whether the Admiralty heard of his design and asked him to continue with it, or whether he pressed his claims himself, is not known. From his autobiography it appears that he pressed his ideas on a number of occasions. Once he had gained permission to build the machine, he was very vocal in its defence.
  In his autobiography he states that after his arrival back in the UK after his experiences with the Germans attack in Belgium and France and the squadron’s continual retreat, he was convinced that every day it became more apparent that the equipment such as we had was not suitable for the demands made upon it. One point in particular struck me very forcibly, and that was the general interest in the scout class entirely eclipsed that of the large battle plane. Many of the older pilots in the squadron were of precisely the same opinion, and when I was in London on a special mission, I again submitted my ideas of a two-engined outfit. At the beginning of the war, when I did this, the reply was that they wanted standard machines and could not afford to experiment. This time it was the reverse, they had made so many experiments they could not undertake anything new, so once more the idea was shelved. For my part I was firmly convinced that the large machine was not receiving our best efforts that I continued developing my ideas without a hitch. Each days work brought new suggestions, and all my evenings and spare time were spent getting out sketches showing details of construction. With money received from the Admiralty for my monoplane, I paid a draftsman in London to work up all my sketches into tangible form, and the few days’ leave which came my way, were spent in pushing the work ahead with all possible speed. Some day we would be obliged to have large machines, therefore I wanted to be ready when that much delayed time arrived.
  Under this Dyott had written in pencil the following notes that appear to be for a following chapter that, if written, is not in the surviving papers.

  Dover Patrol
  Vice Admiral Bacon - on patrol ships his interest and pressure.
  Meeting at Admiralty to consider his statements.
  How many machines. 1 Sir.
  The whole story of building & flying my battle plane. Obstacles of Randall & Brass(?). The Handley Page trick - first disaster my plan from Dunkirk, burned. #1 Retained in England & was used in experiments.

  The following history has been pieced together from the few surviving documents that have surfaced in the British National Archives.
  Dyott enlisted the support of Wing Cdr Lambe and the Admiralty was persuaded to order two prototypes in 1915, the official contract, No. C.P. 106417/16, being issued later. The manufacturer was to be Hewlett & Blondeau of Luton, whom Dyott was familiar with from their work on his monoplane.
  That the Dyott biplane was intended as a fighter is confirmed by the Admiralty Air Department Section Reports where the firm of Hewlett & Blondeau were asked to tender for two Dyott fighters 2 - 120-hp Beardmore Aeroplanes.
  In the terminology of the time the Dyott biplane was a battleplane. The concept of the single engine fighter was still some time off and it was thought that a large machine with a large crew and armament would be able to take the offensive in the air. Another example would be the German A.E.G. K.I. This twin engined biplane developed into a successful G series of day and night bombers. Battleplanes with their load lifting capabilities were prime contenders for conversion to bombers. In the case of the Dyott biplane, there never seems to have been any attempt to adopt it for carrying bombs.
  It has been suggested that the first machine was constructed by private funding, then purchased by the Admiralty and a second one ordered. As the first was finished except for engine fittings by 3 April 1916, it would appear that construction was well in hand by the time the Admiralty asked for tenders. Y Section received the tenders for two Dyott Fighter Aeroplanes in the Week Ending (W/E) 31 March, and recommended that they be accepted, and acceptance was reported for the W/E 5 May 1916, for 2-Dyott fighting biplanes. Contract No. C.P.106417/16 was raised and serial Nos. 3687 - 3688 were allocated to these two machines.
  On Thursday 30 March, Cdr Babington visited regarding the Dyott Fighter. His report noted that the Machine is expected to be ready for trials within a week. It is anticipated that speed of machine will be somewhat low in first machine for practical purposes. No. 3687 was reported as under erection by Hewlett & Blondeau on 12 April 1916, and under test on the 25th.
  Flt Lt Dyott flew No. 3687 on 28 April and 12 May 1916. The report of the Design Section for the W/E 5 May 1916 noted that Stress work has been completed on the Wight 250 R-R machine and on the revised form of the Dyott Biplane. This may be why a Mr Pippard visited Hendon in that reporting period to obtain information on the revised form of the Dyott Biplane. Hewlett & Blondeau were asked to carry out necessary modifications to the second Dyott Fighter in July. The aeroplane was officially delivered to RNAS Hendon on 17 August.
  Hewlett & Blondeau, Ltd, wrote to Flt Cdr Dyott on 26 July 1916, notifying him that the Admiralty had asked them to quote for the extra bracing on front undercarriage, etc., per his earlier communication. This letter is reproduced in detail as it shows that there were tensions between the company and Dyott over the manner in which the construction was carried out.
  The firm wanted drawings as they wanted to carry out the work in a different manner to that of the past which has been prejudicial to both you and ourselves. Delay in the completion and considerable reduction in the cost would have been effected if the work had been left entirely in our hands and we have been deceived over the estimated cost owing to the materials adopted by you whilst in our shops.
  You are of course aware that the design, working drawings and calculations of stresses have been made by our firm when all this important work should have come from yourself.
  You have, on many occasions asked for departures from drawings on work in hand in the shops and without reference to the Firm, with the result that drawings are non existent or not up to date and cannot be put right now.
  It will be in our mutual interest, if when work is in progress, you do not interfere with the men carrying it out under the Firms instructions but refer everything to the Firm as it should be done.
  There were financial problems with the Admiralty paying Hewlett & Blondeau, Ltd for the work done as correspondence between H.E. Hewlett and a Mr F.H. Paget(?) reveal. Paget’s wife had left funds with the firm, subject to recall at any time. Hewlett wrote that they have been trying to get their money from the Admiralty. We are getting on very fast with our new contract & have been pressed to take another at once. He concluded the letter by stating - The plans for George’s machine are going away tomorrow, & the new shop is moving apace. While Paget failed to see how any orders Flt Comdr Dyott could have given you relative to changes in Admiralty machines Nos. 3687 & 3688 can enter into the question of the return of his wife’s money, but he let the subject drop for the moment. Perhaps Paget’s wife was one of the two wealthy benefactors that the Aeronautical Engineer reported as funding the construction of the original Dyott battleplane.
  Dyott had been seconded to the firm to oversee the construction. The financial problems could have arisen from Dyott’s personality. He wrote to his Commanding Officer and various other Admiralty officers complaining about the lack of funding and made himself unpopular. M.H. Goodall reprinted a letter from Dyott to Lambe of 17 March 1916. In it Dyott states that the Work is going ahead nicely, the main wings are finished so also interplane struts and tailplanes. The fuselage has to be covered, also centre section, at the moment we are doing the engine cowling. Lt. Peel sent me a sketch of the camera but omitted the important dimensions which would enable me to make a suitable door for it, so I will have to let the matter drop and install it later.
  The firm received some £1,600 this morning for work done on B.E.’s. No order has been received for my second machine and the letter of conditions referred to on their Admiralty telegram has not arrived, so no quotation can be given. All metal work for the 2nd. Fuselage is finished and the erecting can begin any day; did we know what motors were to be used we could have the entire machine finished in six weeks at the outside.
  Dyott was upset that the Inspector had sent list of requests for information. Personally I cannot see any reason for not writing direct to me, however, to avoid trouble which is going to come quite soon enough I replied that the machine had been modified to suit Admiralty requirements as in my letter to the S.A.C. on November 20th, 1915.
  I put forward that no one is allowed to change, stop or hinder any of my work till the machine has been tested by me. Even if the factor of safety is only two it will be quite safe for test under no load or full load. If the performance and general arrangement meets with approval then it will be time enough to discuss changes if necessary, and higher factors of safety. Furthermore, the firm should receive the £1,000 which had been due them for some time and the balance afterwards, without any arguments. The experiment has been carried out by them and every detail of the work has been passed by me as satisfactory.
  It was originally intended to fit two engines driving opposite handed airscrews, however the two 120-hp Beardmore engines fitted had two-bladed anti-clockwise rotating airscrews.
  The first Dyott, No. 3687, was a handsome parallel-chord, equi-span biplane with the 120-hp Beardmore six-cylinder water-cooled engines suspended between the wings, these being fitted with side radiators. A large centre section spanned the distance between the engines, the outboard sections of the wings having four bays of bracing including that of the engines. Ailerons were carried on all four wings. The undercarriage comprised a single wheel under each engine with a double skid arrangement carrying the axle. A nose wheel was fitted. According to Aeronautical Engineering, the nose wheel was only intended for night use.
  The aircraft was of conventional construction with ply front decking. A crew of three was carried. The pilot sat to port with a large windscreen forward of his position.
  Entry to the front gunner’s cockpit was by a door in the port side of the nose. Armament comprised five Lewis guns. Two were mounted on spigot mounts at the nose above the fuselage, with another two at “portholes” in the nose. On the first version of the type a gun rail, containing six spigot mountings, ran completely around the front gunner’s cockpit above the fuselage. The two Lewis guns could be moved to any of these mounts. The fifth was on a spigot mount behind the wings for the third crew member. Dyott No. 3687 was reported by Hendon as being erected by Hewlett & Blondeau on 11 April 1916. The first machine was modified and it is thought that the second was completed to incorporate these modifications. The engines were cowled with frontal radiators; the top decking was raised and continued at this height back to the pilot’s cockpit. The gun rail is not visible in photographs and it is not known if the same arrangement for the guns was behind the raised decking.
  After engine runs the first aircraft was taken by road to Hendon. Hendon reported that No. 3687 was ready for testing on 24 April 1916, and was under test the next day. On the 28th, it reported that it was flown by Flt Lt Dyott. It had taken to the air on its first flight on 25th. The engines overheated and the cowlings were removed and the radiators mounted above the engines in an attempt to increase cooling. A new tailplane was fitted after testing showed that the original was too small. This was fitted on 27 May. Testing continued. The Aeroplane described activities at Hendon over the weekend of 5-6 August 1916, and although many were missing the pre-war Hendon, flights were still being given, the Grahame-White three-seater being mentioned. On Saturday there were many machines of many kinds in the air, from single seater Caudrons to large Curtiss and even larger Dyott. This must have been No.3687. It is strange that a new experimental machine should have been on public display, in such a fashion, during wartime.
  On 20 September 1916, it was noted that after its trials at Hendon, it was to be allocated to ‘K’ Section, presumably located at Eastchurch, for trials, then to Dunkirk. Its previous allocation to No. 3 Wing was cancelled.
  The second machine, No. 3688, joined the first at Hendon by 2 September 1916, where it was recorded as a great improvement over No. 1 and is fitted with W/T receiver and transmitter.
  Alec Ogilvie was one of the greater figures in the aeronautical movement, his early experiments and experiences leading him to purchase Short-Wright No. 2. He obtained British certificate No. 7 on 15 May 1911. He went to the USA every year and had a close association with the Wrights. He accompanied Frank McClean on his Nile expedition wherein they took Short S.80 from Alexandria to Khartoum.
  Since the end of 1912, he was working on an Air Speed Indicator, that was tested by the Navy at the 1913 Navy manoeuvres. This was later adopted by the air services. He had been granted a provisional Sqn Cdr commission in joining the RNAS in 1915 and placed in charge of instructional flying at Eastchurch. From March 1916 to March 1917, he was in charge of the Aircraft Repair Depot at Dunkirk. Promoted to W/Cdr he was transferred to the Air Board as Controller of the Technical Department when that was set up in early 1917. After resigning his commission, he set up as a consulting engineer in 1919.
  Ogilvie wrote that he had visited Hendon on 26 September 1916, to see Dyott and see how his second machine was getting on. It is most beautifully fitted up for reconnaissance work and has a most formidable array of guns. No doubt much more speed would be obtained by 160 h.p. engines but in no case will the machine have any chance of escaping from a hostile machine. It will have to be able to defend itself by its superior armament. No doubt the only way to prove the point by having the machine on trial at Dunkirk to see how it really gets on in war conditions. The greatest difficulty would be housing it on the French aerodrome, as it is 75 feet wide and unable to fold.
  Both Dyott biplanes remained at Hendon until early October when No. 3687 went to the Experimental Armament Depot on the Isle of Grain. Given the power available and the weight of armament, the machine was underpowered. At some the first machine was fitted with 230-hp BHP engines in an effort to improve the machine’s performance.
  No. 3687 was to be fitted for experiments with a 2-pdr Vickers gun at Grain. For the W/E 28 October 1916, the mounting for 2-pdr in the Dyott fighter was in hand. Neither J.M. Bruce nor H.F. King mention it when discussing the armament of the Dyott, and it is not known if it was ever fitted to the airframe. It was recorded as having flown at Hendon by Flt Lt Johnston on 10 November 1916, and also flown on the 11th. The machine was noted as deleted on 24 March 1917, but was repaired instead and continued on at Grain being recorded there 25 May 1918. Its final fate is unknown.
  The second machine, No. 3688, was delivered to Hendon for erection on 25 August 1916, and flown on 5 October by Flt Lt T.D. Hallam. More information is available in the Weekly Section reports of the Admiralty Air Department:
  W/E 06 Oct 1916. ‘K’ Section. Hendon undergoing designer’s trials.
  W/E 13 Oct 1916. ‘K’ Section. Hendon undergoing designer’s trials.
  W/E 20 Oct 1916. ‘K’ Section. Eastchurch undergoing trials. W/E 27 Oct 1916. Eastchurch awaiting propellers.
  Modifications were apparently made to No. 3688 and it was transferred to Dunkirk for service trials. It returned by 16 November 1916. Sqn Cdr F.K. McClean wrote that the machine is devoid of the necessary flying qualities on this station. This machine to be transferred to another Station or deleted from commission: useful parts as arisings are to be taken on charge at Station as deleted. Engines to be returned to Survey Section.
  In September 1917, Charles Grey of The Aeroplane conducted one of his usual trenchant articles against those in authority. This article, titled ‘On Some Lessons from the Enemy’, he tries to make the case that all the German superior aircraft were all derived from French or British aircraft. The Fokker monoplane was derived from the Morane-Saulnier, but Grey contended that his scout biplanes (were derived) from the Sopwith and Bristol designs, and his two-seaters from the Avro. Whence he stole his Gothas I do not profess to know, but certainly out multiple engine Shorts were long before any German effort with multiple engines, and the Dyott twin-engined machine, designed in 1914, built in spite of official disinclination in 1915, and flown successfully in 1916, when the design was well over a year old, was as near as no matter exactly according to best modern practice, albeit hopelessly underpowered, again thanks to official disbelief at the time. Truly the Dyott was under powered with its first engines, this was known before the machine first flew , however the performance figures for the machine with different engines has not been discovered to date.
  Charles G Grey was never one to let facts stand in the way of his crusade against the Royal Aircraft Factory and the administration of the RFC/RNAS. In the 27 November 1918, issue of The Aeroplane Grey devoted five pages to an attack on the official news releases by the Air Ministry. To the official contention that the first British aircraft specifically designed for Bombing was the Short Bomber he wrote that this was sheer unadulterated nonsense. The twin-engined Dyott of 1915 and the contemporary twin-engined Fairey “Folder” were “specifically conducted for bombing” long before the technical imbeciles of the R.N.A.S. thought about mangling a perfectly good seaplane and turning it into a perfectly hopeless bomber. The poor mangled Short never “did most useful work in France, ” though that was not the fault of Short Brothers, and the type was washed out after only a few trips had been made over the lines on it. The machines, however, were delivered in quantities and burned without being used.
  The Naval "experts” had washed out the Dyott and the Fairey long before that, and so the “first British machine specifically constructed for bombing which ever came into regular use about a year and a half or two years after its energetic designer-constructor had put up wonderful demonstrations of its capabilities and after various young and intelligent officers had got themselves severely disliked by trying to drum its uses into the thick heads of fossilised seniors. It can be seen from this type of reporting at such an early date why the Dyott has been referred to as a bomber rather than a fighter.
  Given Dyott’s personality, the problems with obtaining powerful engines, the state of aerial fighting and the changes that were developing at such a pace on the Western Front, it is no surprise that the Dyott battleplane was not accepted for development as a fighter. Whether it could have been developed into a serious bomber will never be known.

Dyott AT Battleplane Specifications
Source 1 2 3 All approx
Span 70 ft 0 in - 70 ft
Length 46 ft 3 in - 50 ft
Height - - 12 ft
Chord 6 ft 4 in - -
Span tailplane 20 ft 0 in - -
Light Weight, lbs - 3,800 -
Military load, lbs - 850 -
Gross Weight, lbs - - 7,800
Wing Area - 874 ft2 -
Fuel, gallons - 114 -
Oil, gallons - 91 -
Speed (ground level) - 63.3 kts -
Climb to
1,000 ft - 4 min 23 -
2,000 ft - 9 min 25 -
3,000 ft - 14 min 56 -
4,000 ft - 21 min 29 -
5,000 ft - 29 min 36 -
6,000 ft - 41 min 05 -
Engines - 120-hp Beardmore (130 h.p. @ 1250 rpm) 120-hp Beardmore. Later 230-hp BHP
  1. Air Dept drawing. TNA AIR1/716/27/19/30.
  2. RAF Museum J.M. Bruce Collection Box 24.
  3. F.K. Mason data. (Note stated to be approximate).
Dyott AT Battleplane 3687 Spring 1916
Dyott AT Battleplane 3687 August 1918
Dyott AT Battleplane 3688 Autumn 1916
The first Dyott Bomber, No 3687, in the aircraft's initial configuration with uncowled Beardmore engines, probably photographed at RNAS Hendon in August 1916. First flight was on 25 April 1916.
Close-up of No. 3687 in its original form showing the front gunner's position in his spacious cockpit, gun rail with Lewis gun, pilot offset to port.
No. 3687 with a Vickers 2-pounder Mark IV gun. Note how the machine is balanced on its wheels, the tailskid being off the ground. 22 November 1916. (via Mary Hagan)
View of the modified No. 3687.
No. 3687 at the Experimental Armament Depot, Isle of Grain, in 1918, after being fitted with 230-hp B.H.P. engines. The rudder is balanced and a tripod gun mounting is fitted in the front gunner's position.
No. 3687 with Balanced rudder, probably when at the Experimental Armament Depot, Isle of Grain, in 1918, after being fitted with 230-hp B.H.P. engines.
The second Dyott Battleplane No. 3688 with closely cowled engines.
A close-up of No. 3688. The radiators, fully cowled engines and revised landing gear are noteworthy.
Dyott Bomber. The modified aircraft with deeper coaming round the front cockpit, cowled engines and frontal radiators.
This view of No. 3688 shows the deeper fuselage top decking.
Construction of a Dyott biplane.
Construction of a Dyott biplane.
The Dyott AT Battleplane
The Dyott AT Battleplane
The Dyott AT Battleplane
The Nieuport Nighthawk was the most successful of the Dragonfly powered aircraft. In its various guises it was still in service in Greece at the start of World War II.
Nieuport also used the triplane layout for their London bomber.
Installation of the Sunbeam Arab engine in a Norman Thompson NT-2B No. N2294.
Norman Thompson NT-2B No. N2294, the last of the batch of 100 (N2260-N2359) to be produced before the rest were cancelled.This flying boat started out with a Beardmore engine that was replaced by the Arab.
Noel Pemberton Billing leaning on his P.B.1 flying boat at the 1914 Olympia Aero Show.
The P.B.9, the "Seven Day Bus" being readied for its first flight on 21 August 1914.
Scout biplane PB9 later PB13 was built in seven days in August 1914, was tested at Netley and Brooklands and taken over by the RNAS.
Pemberton Billing P.B.23E and P.B.25 Scouts

  The early years of aviation are populated with eccentric inventors and moneyed aeronauts who took to the latest adventurous activity be it ballooning, motor car racing or heavier than air flight. One of the most colourful of these personalities in British aviation, who still stands out today, was Noel Pemberton-Billing. It was his activities as “First Air Member” in the British Parliament that led to his being more than a footnote in aeronautical history, however, that is not the story here.
  Born on 31 January 1881, in Hampstead, Noel soon showed his independent ways when he ran away from home at 14 and caught a sailing tramp to Mozambique. He joined the Natal Mounted Police in South Africa. Was wounded twice in the Boer War, returned to the UK in a hospital ship, returned to South Africa and started the British South African Autocar, combining his interests in journalism and autocars.
  Returning to the UK he became interested in aeronautics around 1904 when he built a glider. In 1909, P-B, as he was known, tried to establish a working aerodrome with factory and facilities for aviators to reside and have their aircraft hangered on the one site. “The Colony of British Aerocraft” in Essex failed within a year. It was to be 1914 before P-B again came to the fore in the aviation press. He made a wager of £500 with Frederick Handley-Page as to whom would be able to learn to fly and obtain their Royal Aeronautical Certificate (RAeS) as a pilot in a day.
  P-B could not get any of the schools at Brooklands lend their valuable aircraft to such a venture and he was forced to purchase his own aircraft, an old 50-hp Farman. He obtained the services of Robert Barnwell of the Vickers School as his instructor, and on the morning of 17 September commenced at 5.45 in the morning. At 9.15 the official observers from the RAeS and P-B took off and performed the required test. Despite stalling, and narrowly avoiding a crash, he went on to perform all the required tests and was awarded Aviator’s Certificate No. 632.
  The following September P-B took over premises in Woolston where he began to construct aircraft. Flight recorded that Pemberton-Billing Ltd were set up as manufacturers and sellers of seaplanes, aeroplanes, and other aircraft carried on by N. Pemberton-Billing, at Southampton. Several machines were built or under construction when the war broke out. P-B completed the “Seven Day Bus” or P.B.9 in six days and 10 hours after chalking out the design on the factory walls! Joining the RNAS as a Temporary Acting Flight Lieutenant, he organised the successful raid on the Zeppelin sheds at Friedrichshafen by Avro 504 biplanes.
  The P.B.23E of 1915 was a single-bay pusher biplane fighter powered by an 80-hp Le Rhone rotary engine, along the lines of its contemporary, the De Havilland D.H.2. A contract was let for a single example that received the RNAS serial No. 8487. The aluminium covered nacelle was suspended between the unstaggered wings on a complex system of struts. The nacelle was of circular cross section and covered with aluminium sheets. A single Lewis gun was mounted low down at the front of the nacelle where it was out of reach of the pilot. The lower wings had a marked dihedral, but the mainplanes had no sweep-back. The tail booms were thick and converged to meet at the rear tailplane spar. Twin fins and rudders were fitted. Unusually the tail booms had no cross bracing. Because of the shape and shiny aluminium finish, the type was given the nick-name ‘Sparklet’ after small, metal soda-syphon charger bulbs.
  The Air Department of the Admiralty weekly reports give some idea of the progress of the machine.
  On 8 August 1915, Sqn Cdrs J.W. Seddon & J.T. Babington went to Supermarine at Southampton, to inspect the P.B.23E. On Sunday, the 29th, the “Experimental Pilot”, Seddon, visited Southampton to inspect pusher scout and see her towed on own wheels to Hendon.
  I went to Southampton with Lieut. Pemberton Billing to run over his 80 H.P. LE Rhone engine Pusher Scout now nicknamed the Push Proj, and to watch her towed to Hendon. This towing experiment was most interesting. The main planes and Empennage were stowed on the top of a fast light lorry, with the crew of five erectors inside, while the tail booms were brought together and shackled and hitched up to the rear of the lorry.
  The start was made about 4.00 a.m. and easy running was made to Winchester until it was quite light, from there the 75 miles to Hendon were made in 3 hours, the speed being often up to 40 m.p.h. On arrival at Hendon the erectors had breakfast and commenced erecting about 10.30 a.m. At 5 p.m. the machine had been erected and trued up and the engine run.
  At 6.0 p.m. I made the initial flight and found the machine nearly in correct balance and extremely nice to handle in the air with a very high performance.
  The report of the ‘Experimental Pilot’ are different from the history of No. 8487 as recorded in Sturtivant & Page, and are therefore detailed hereunder.
  On Monday the 30th, the report noted: - To Hendon for initial flight Push-Proj. The next day he went to Hendon to test Push-Proj. Wednesday he again went to Hendon flying the machine in the a.m. and p.m. before S.C.A. Thursday saw him with Lt Pierren (French Army pilot) and Lt Pemberton Billing, go to Hendon and flying the Push-Proj.
  Under the title “Further Flights in Push-Proj” Seddon recorded that the only additional point of interest to note at present is that a measured speed test has not yet been carried out and that the flight on Thursday was made in considerably gusty weather; while Squadron Comdr. Babington flew the machine in even more disturbed conditions on Friday. Both he and I are able to report that this machine behaves extremely well under such conditions.
  These reports of the machine’s flying qualities were probably the reason why the following report was included in “G” (Armament) section’s report for the W/E 3 September, 1915. A member of “G” Section, Lieutenant Pemberton-Billing, has constructed a new Pusher Machine, which is the best design of single-seater fighting machine yet in existence.
  It is recommended that experiments should be carried out in this machine with various types of mountings for machine guns forthwith. This would necessitate the purchase of the machine and its immediate allocation to the Experimental Station.
  These reports are different from the instability that Andrews and Morgan report in Supermarine Aircraft since 1914, (Putnam, UK, 1989). According to these authors, in the trials at Hendon, No. 8487 showed instability caused by an excessive rearward centre of gravity. Considering the changes made to the wings of the P.B.25, their contention appears to have been correct.
  On Monday 20 September, Seddon went to Southampton re repairs and alterations to P.B. Scout. This probably refers to the damage done when Babington suffered a forced landing on 6 September, in a cornfield one mile from Chingford aerodrome.
  These repairs and alterations appeared to have been satisfactorily carried out, but the chassis looks to require a direct strut between the lower plane and engine bearers.
  The aileron levers have been entirely altered and much better streamlined. A Lewis gun has been mounted in place of the mockup. The Lewis gun was in the extreme nose and out of reach of the pilot.
  Seddon then flew the P.B. Scout from Hendon to the Isle of Grain on Friday 24th, apparently without a serial number. This flight was made without incident, except that I have to remark on the bad qualities of this machine as regards handling on the ground, in the air it is delightful from every point of view.
  With this sort of endorsement, it is not surprising that Pemberton Billing’s Supermarine Aviation Works received a contract for 20 of the improved P.B.25 Scouts, the first being delivered in June 1916.
  No. 8487 had a long life in service. It underwent further modifications as recorded hereunder, but their context in the story of the Pemberton Billing scouts in unknown. The Weekly report of “K” section for W/E 2 June 1916, recorded the 80-hp P.B. Scout being assembled at Port Victoria for the experimental flight with Sub Lt nominated as the pilot. The next report was left blank and the machine fails to be mentioned in following reports until July.
  The Royal Navy Aeroplane Repair Depot at Port Victoria reported for the W/E 28 July 1916, that on Pemberton Billing No.8487. Making new rudder and elevator control clips and fitting to existing stays; soldering wires and making new under shield.
  That for the following week reported:
  Fixing aluminium on nacelle and making all necessary work for alteration of control wires.
  Making new undershield and Pulley control clips. New fair leads for rudder and elevator.
  Work was continuing on the controls and nacelle during the W/E 18 August 1916. Making new control leads for rudder and elevators. Repairing shields and cowl. Fitting Aluminium to nacelle.
  On 3 October, Flt Lt Sanford took the machine up for a 10 minute test flight. Apparently, whatever the work carried out was to modify, it did not work as hoped, as No. 8487 was again stripped of its aluminum from the nacelle and all rudder controls, pulleys, etc., were altered. Modifications were completed by November 1916, the machine still being at Grain when deleted on 7 March 1917.
  Pemberton Billing entered Parliament as the member for East Hertfordshire on 10 March 1916, and it was here that he had the most effect on the British air services. P-B had become less interested in the work of developing his ideas as he became more involved in his various political activities, and now gave up his interests in the company and a new one was formed as the Supermarine Aviation Works Ltd.
  The P.B.25 differed from the P.B.23E in having 11° sweep-back to the mainplanes and inversely-tapered ailerons. A lengthened nacelle was fitted, this time fabric covered, but faired to a streamlined circular cross-section. The undercarriage had two V-struts attached to the lower centre-section. The fins were enlarged to match those of the modified P.B.23E.The first machine, No. 9001, was fitted with a 110-hp Clerget, but the rest had the 110-hp Gnome Monosoupape rotary engine.
  Again, the Admiralty Air Department reports give some background to these machines.
  In the first week of June 1916, a P.B. Scout with 100-hp engine was At the Experimental Section for preliminary flights under Flt Cdr Bone, but the engine was defective. This would have been No. 9001 that was delivered to Chingford on the 6th. Bone tested the machine on the 11th and he reported that the preliminary flights on this machine, show that machine is well balanced and easy to control. A certain amount of trouble has been experienced with the 110 Clerget motor and further trials will be carried out when a more suitable propeller is fitted.
  Harris Booth’s Design Section issued four-bladed propellers Nos. A.D.506M for the P.B. Scout 110 Clerget, and A.D.509M for the P.B. Scout 100 Mono. Propellers 140 and 141 have been sent to Chingford Air Station for trial on the P.B. Scout. Bone tested a new propeller in the W/E 23 June.
  Flt Lt Hardstaff tested the machine on the 26th and reported that exhaustive tests with engine vibrations at various speeds and with various propellers were carried out with the machine on the ground. The lengthened tail appears to balance these machines with engine on. Tests to improve the balance are proceeding.
  In early September 1916, the 4th and 5th Scouts were in course of erection. Several strut sockets on the 4th machine have had to be rejected as it was found that they were not in line with the struts when nacelle was in position.
  All work on these machines is well advanced and it is considered that the remainder could be delivered very quickly if engines (100 Mono) are available.
  This would also greatly assist the firm in their other work as they have no facilities for storing these machines while awaiting
  An undated report filed with October reports noted that 4 machines of the Pemberton Billing Scout type have now been delivered; 3 more are in the course of erection, and the nacelles, wings and all fittings are ready for the next seven machines. No action has been taken as regards shifting the position of the wheels or fitting the extra rudder on these machines.
  These machines were delivered to Eastchurch. The late Jack Bruce noted that the P.B.25 was promptly given the most ribald and unprintable nickname. W. Geoffrey Moore wrote that I was a type chaser and could not resist climbing into any machine I had not flown. ... It was an absolute beast to fly. Was also known for obvious reasons as “The flying penis. ”
  The high centre of gravity and the pilot’s position in the nacelle did not engender confidence in pilot’s in the event of a less than perfect landing. The controls were also unusual.
  Instead of using cables over pulleys, a system of Bowden cables was used. These would often not work at first then give way to result in control surfaces moving abruptly. These characteristics were less marked once airborne, but making take-off, landing and taxiing distinctly uncomfortable.
  All 20 P.B.25 pushers were delivered. The last eight were delivered to Killingholme without engines. Sir Austin Robinson wrote that Killingholme, until it was cleared out to make room for the American H16s, had much more shed accommodation than was needed for the war flight and the school flight. This contained an accumulation of aircraft, some of current types in store, some of aircraft that nobody had ever quite got round to burning or reducing to produce. One wishes one could now walk round it as it was in 1917 or 1918. We had, as you know, a number of Porte Boats. There were also a large number of Beardmore W.B.IIIs, presumably in case the Fleet came into Immingham and wanted replacements in a hurry. A number of A.D. Boats. A few Pemberton Billing 'Push-Proj’s - I have a photograph of one we assembled and someone tried to make fly. (Author’s underlining).
  The P.B.25 was tested at Grain and used at Eastchurch and possibly Killingholme, but the majority were sent there had no engines. It was unloved and feared by pilot’s, who did not trust its flimsy structure in the event of a nose-over on landing.
  Perhaps the last word on Pemberton-Billing should go to one who worked with him. Joseph C.C. Taylor joined Pemberton-Billing Ltd at Southampton towards the end of 1915. He recalled that Pemberton-Billing was a most dynamic personality, with a great flair for inventing things, and we were always working on one or other of his pet ideas. Many of his inventions were really sound, but years ahead of their time, and for that reason were usually turned down.

Source 1 2
Type P.B.23E P.B.25
Span upper 33 ft 0 in 32 ft 11 1/2 in
Span lower 31 ft 0 in -
Chord upper 4ft 2in -
Chord lower 3 ft 6 in -
Length 20 ft 7 in 24 ft 1 in
Height 9 ft 10 in 10 ft 5 in
Airscrew dia 8 ft 0 in -
Span tailplane 16 ft 0 in -
Wing Area - 277 ft2
Empty Weight, lbs - 1,108
Loaded Weight, lbs - 1,541
Max Speed at G.L. - 89
Max Speed at 10,000 ft - 83.5
Climb to 6,000 ft - 11 min
Climb to 10,000 ft - 21 min
Endurance - 2 1/2 hrs
Engine 320-hp Dragonfly -
  1. Air Department sketch of Supermarine Push Prog. TNA AIR1/716/27/19/30.
  2. J.M. Bruce data.

Serial Allocation
Serials Contract Notes
8487 C.P.62042/15 P.B.23E
9001-9020 C.P.134727/16 P.B.25. 9007-9011, 9014-9020 delivered Killingholme without engine.
Pemberton Billing PB23E, September 1915
Pemberton Billing PB25, 9001
Pemberton Billing PB25, 9005
The P.B.23E in a factory setting. The marking on the rudder appears to be a small flag.
The P.B.23E with enlarged fins. Note the elaborate logos on the rudder.
The sole Pemberton-Billing P.B.23 with 80hp Le Rhone engine, metal-clad nacelle and pronounced dihedral on the lower wing; the aircraft was affectionately known as ‘Sparklet’ or ‘Push-Proj’; the Lewis gun can just be seen projecting from the front of the nacelle.
Appears to be assembling the P.B.23E in the field.
The original caption said that these photographs of the P.B.23E were taken after a crash; however, no damage can be seen on the machine and it is thought that the machine is being assembled, possibly at Hendon after being taken there on 29 August 1915.
The P.B.23E under construction at the Woolston works of Pemberton Billing Ltd. AHT AL0232-007.
View of the P.B.23E erected in the Woolston works. The dihedral to the bottom wings stands out markedly in these views. The gun is a mock-up and was positioned out of reach of the pilot. It is not known if the position was changed when the Lewis gun replaced the mock-up. AHT AL0232-008.
The first production Pemberton-Billing P.B.25 Scout, No 9001, with 110hp Clerget engine, swept wings and fabric-covered nacelle.
No. 9001 had a cutout in the top of the nacelle for a machine gun and a two-bladed propeller. The other P.B.25 scouts do not seem to have had this facility for mounting a machine gun although the P.B.25 scouts were assigned to the Eastchurch Gunnery School.
Compare the fabric covered fuselage of the P.B.25 with the aluminum panel covered nacelle of the P.B.23E. The first machine of the contract, No. 9001 had a 110-hp Clerget 9Z rotary engine with two-bladed propeller, and the rear panels to the nacelle are different from the others of the batch that had the 100-hp Monosoupape rotary engine.
No. 9002 must have been painted a light colour overall as the metal nose cone is the same colour as the rest of the machine.
No. 9002 showing the four bladed propeller, the different end panels to the nacelle and the very low undercarriage.
View of No. 9003, flown by Rochford at Eastchurch, September 1916. The height of the nacelle required ladders to provide access for maintenance. Note the Bristol Scouts in the background.
Rear view of a P.B.25 on a training aerodrome.
No. 9004 with a Breguet in the background.
Posing with a dark coloured "P.B. Scout", however photographs of the P.B.25 with armament have yet to appear.
No. 9005 in the dark finish. Only the first couple of machines sported the light finish.
No. 9005 in the dark finish. Only the first couple of machines sported the light finish.
No. 9006.
A dark doped P.B.25 with naval personnel, late delivered machine as its dark doped airframe. Eastchurch. Note the lower wing cockades have a white outline.
Three RB.25 trainers at Eastchurch, June 1917.
Line up at Eastchurch, June 1917.
In this view the seven P.B.25 biplanes can be seen to have no engines installed. Nos 9008, two unknown, 9009 and 9007 can be identified on the original print. These three machines were delivered to Killingholme minus their engines.
This line-up of seven fuselages would appear to be at the Woolston works. The wooden structure of the nacelle is well illustrated.
Pemberton Billing P.B.25
Pemberton Billing P.B.25
Pemberton Billing P.B.25
Pemberton Billing P.B.29E and Supermarine P.B.31 E Night Hawk

  The Royal Navy was in charge of the defence of the United Kingdom against air raids and after the attacks by Zeppelins, Pemberton Billing (PB) was given indefinite leave from the RNAS by the Superintendent of Aircraft Production, Commodore Murray Sueter, to design and manufacture an anti-Zeppelin aeroplane.
  The battle plane that he designed was in accordance with the ideas PB had expressed in his book Air War: how to wage it (Gale & Polden Ltd, UK, 1916). In his chapter ‘The Defence of Great Cities by Night and by Day’ PB wrote that by Night: - A fleet of defending aeroplanes is necessary. Each machine must be so armed as to be capable of destroying an airship at a range equal to the range of its own searchlight, which must be not less than one mile. It must also carry a searchlight driven independently of the engines. It must have at least a speed of 80 miles an hour in order to overtake airships.
  It must be able to fly as slowly as 35 miles an hour in order to economise fuel and to render accurate gunfire and night landing possible.
  It must be able to carry fuel for 12 hours’ cruising at low speed, to enable it to chase an airship to the coast. It must be able to climb to 10,000 feet in not more than 20 minutes.
  It must be fitted with control-gear for two pilots, to allow one to relieve the other, and in the event of a gunner not being carried, each or either pilot must have equal facilities for working the guns, bombs, and searchlight.
  The engines must be silenced.
  The pilots must have a clear view and arc of fire above, in front and below.
  (N.B. - All the above requirements are within the capacity of any competent aeroplane designer.)
  The defending fleet must consist of at least 50 such aeroplanes, continually ready to fly at any moment. Therefore 150 such machines at least must exist in an undamaged condition.
  Fifty pilots must always be on duty, with 25 in reserve. The machine was to patrol the sky for 12 hours with two pilots so that one could relieve the other. It was to have a searchlight and weapons that had a range equal to the range of its searchlight. It must be able to fly slowly at 35 mph in order to conserve fuel and to make night landings safer. It should be able to climb to 10,000 ft in 20 minutes.

The P.B.29E

  Pemberton Billing stated that when Sueter instructed him to take indefinite leave to design and build an anti-airship aeroplane, he designed and built the P.B.29E in seven weeks. The machine that emerged as the P.B.29E, was a large, frail looking quadruplane with a biplane tail with three rudders. The upper wing had a greater span than the other three wings. There was no stagger to the wings. Power was supplied by a pair of 90-hp Austro-Daimler pusher mounted engines driving four-bladed propellers. The engines had a frontal radiator and were slung under the second centre-section that was attached to the upper longerons. The fuselage was rounded at the front where the searchlight was mounted and of inverted triangular cross-section at the rear. A deep nacelle structure that filled the space between the upper and the second wing. This had a gunner’s platform at the top. There were two cockpits, one just in front of the wing leading edge and the second behind the trailing edge. They were connected by an intercom and dual control. The landing gear had two forward wheels to prevent he machine overturning in a bad landing. The wings were braced as a biplane, the landing and flying wires passing through the intermittent wings.
  The P.B.29E was delivered to RNAS Chingford by lorry on 1 January 1916. Flt Lt Sidney Pickles, later Fairey test pilot, flew the machine on 1 January 1916.
  Flt Cdr G.H. Dyott, he of the Dyott battleplane, was an observer and arrived at Chingford on the 15th. Chingford reported that the Pemberton-Billing quadruplane was tested today on 16 January 1916. Dyott stated that he was fortunate in being able to see the machine being tried out on the grounds when Pickles made a short hop.
  The P.B.29E was not given a RNAS serial number and appears to have been flown only a couple of times, including that by Commander J.W. Seddon, before it was written off in an accident at Chingford in 1916. Despite the obvious faults in the machine, it was seen as having some merit and two of the P.B.31E improved Night Hawk Tractor quadruplanes were ordered from Pemberton Billing Ltd under Contract No. CP130778/16 on 24 November 1916, as Nos. 1388 - 1399.

Specifications P.B.29E
Serials Contract
Span upper wing 60ft 0 in
Span lower wing 57 ft 0 in
Length 36 ft 10 1/2 in
Height 17 ft 8 1/2 in
Span 15 ft
Chord 3 ft 1 1/4 in
Airscrew dia 9 ft 0 in
Engines 90-hp Austro-Daimler
The P.B.29E Quadruplane at the Woolston works in 1916.
The P.B.29E at Chingford for testing. The Austro-Daimler engines are mounted in pusher configuration. The triangular section rear fuselage is clearly seen. Dyott stated that the triangular fuselage section does not give much rigidity. He also considered that a large-area monoplane tail would be better than the small biplane tailplane of the machine.
The extraordinary P.B.29E anti-airship quadruplane intended for prolonged nocturnal cruise.
A poor but interesting front elevation of the P.B.29E. There appears to be no access to the upper gun nacelle while in flight.
Pemberton Billing P.B.29E and Supermarine P.B.31 E Night Hawk

  The Royal Navy was in charge of the defence of the United Kingdom against air raids and after the attacks by Zeppelins, Pemberton Billing (PB) was given indefinite leave from the RNAS by the Superintendent of Aircraft Production, Commodore Murray Sueter, to design and manufacture an anti-Zeppelin aeroplane.
  The battle plane that he designed was in accordance with the ideas PB had expressed in his book Air War: how to wage it (Gale & Polden Ltd, UK, 1916). In his chapter ‘The Defence of Great Cities by Night and by Day’ PB wrote that by Night: - A fleet of defending aeroplanes is necessary. Each machine must be so armed as to be capable of destroying an airship at a range equal to the range of its own searchlight, which must be not less than one mile. It must also carry a searchlight driven independently of the engines. It must have at least a speed of 80 miles an hour in order to overtake airships.
  It must be able to fly as slowly as 35 miles an hour in order to economise fuel and to render accurate gunfire and night landing possible.
  It must be able to carry fuel for 12 hours’ cruising at low speed, to enable it to chase an airship to the coast. It must be able to climb to 10,000 feet in not more than 20 minutes.
  It must be fitted with control-gear for two pilots, to allow one to relieve the other, and in the event of a gunner not being carried, each or either pilot must have equal facilities for working the guns, bombs, and searchlight.
  The engines must be silenced.
  The pilots must have a clear view and arc of fire above, in front and below.
  (N.B. - All the above requirements are within the capacity of any competent aeroplane designer.)
  The defending fleet must consist of at least 50 such aeroplanes, continually ready to fly at any moment. Therefore 150 such machines at least must exist in an undamaged condition.
  Fifty pilots must always be on duty, with 25 in reserve. The machine was to patrol the sky for 12 hours with two pilots so that one could relieve the other. It was to have a searchlight and weapons that had a range equal to the range of its searchlight. It must be able to fly slowly at 35 mph in order to conserve fuel and to make night landings safer. It should be able to climb to 10,000 ft in 20 minutes.


The P.B.31

  The Admiralty Air Department Section reports throw some light on the P.B.31E’s construction history.
  “Y” (Materials) Section for the W/E 10 March 1916, reported for the Supermarine Co that the draft specification has been drawn up for 2 Quadruplane Pusher Aeroplanes (Night Hawk) and has been sent to all Sections concerned. These machines will be ordered in place of a number of the PB. Scouts of which the firm have an order for 20. The number of the PB. Scouts to be such as to afford a financial adjustment.
  That of “D” (Drawing Office - Design) Section for the W/E 20 May 1916, reported that a representative of Messrs. Supermarine was interviewed with reference to the stresses in the PB. Quadruplane, and various recommendations were made with a view to strengthening the main structure of this machine. That for W/E 4 June that another interview had taken place with a representative of the Supermarine Co in connection with the Firms proposals for strengthening the PB. Quadruplane, and the stress work on this machine was afterwards completed.
  A report from “I” (SCA - Contracts) Section in September noted that the quadruplane (Night Hawk) is now being dismantled previous to covering planes. This indicates that the machine was constructed and assembled and now that the parts had fitted in the trial assembly, they would be covered with fabric and doped.
  The P.B.31E Night Hawk No. 1388 emerged from the Supermarine Aviation Works Ltd, as the company was called after PB sold his interests and left to pursue his political ambitions. Again, it was a large quadruplane but looked neater in refinement and more workmanlike than the P.B.29E. It is thought that the wings and tailplane of the P.B.29E, or parts thereof, were incorporated into the new machine. The tailplane appears the same but with two rudders. The fuselage was a continuous square box section, completely filling the space between the second and third wings. The cockpits were enclosed in a folly glazed section that led to the conning tower structure that held the gunner’s positions on the top wing. The pilot sat to starboard just ahead of the wing leading edge. There was no dual control and there was a spare seat beside the pilot for his co-pilot. Although the machine was designed for a crew of five, the published weight of the machine showed that a crew of three was the maximum.
  Power was this time supplied by two ten-cylinder 100-hp Anzani air-cooled radial engines. Fuel was carried in nine separate tanks that were fitted with interchange devices that enabled any tank or combination of tanks to be used. Any tank hit by gunfire could be isolated.
  Ailerons were fitted to all four wings. The wing cellule had three bays of interplane bracing with the landing and flying wires extended from the upper wing directly through the intermediate wings to the lower wing.
  A gunner’s cockpit with Scarf mounting was in the nose where the searchlight was mounted on gimbals that allowed the searchlight to be elevated, depressed or traversed in azimuth to either side. The front gunner controlled the searchlight from his cockpit. The searchlight was powered by an auxiliary 5-hp ABC two-cylinder engine-driven generator. This unit also provided heating for the cockpit cabin. This is believed to be the first time that an auxiliary power-plant was fitted to an aircraft in the United Kingdom. Another gunner’s position with Scarf ring was situated at the top plane. Forward of this was a special mounting for a 1 1/2-lb Davis Recoilless Gun.
  The report of “G” (Armament) Section for the W/E 13 October 1916, noted that the first experimental Davis Gun machine, the Robey Peters fighter had crashed and burned on one of its first trial flights due to a weakness in the top plane extension. The 2nd experimental Davis Gun machine the Supermarine Quadriplane (sic) with one 2pdr Davis and 2 machines (sic) is now being fitted with its mounting.
  “A.2” Section for the W/E 27. October 1916, put forward to accept firms tender for two ‘Night Hawk’ Aeroplanes Nos. 1388/9.
  No. 1388 was completed in November 1916, and delivered to Eastchurch the following month. It was flown by Clifford Prodger in February 1917, but by then it was realized that ordinary aircraft could undertake the task of intercepting Zeppelins. The P.B.31E would only be successful if a Zeppelin ran into it on its patrol. It had neither the speed to catch a Zeppelin nor the climbing ability to catch one that could drop its water ballast and rise vertically at speed. J.M Bruce records that the aircraft was given the name Night Hawk, but this was never official. However, the Admiralty Air Department section reports use this name in their reports.
  The P.B.39E was scrapped on 23 July 1917. H.V. Potter related the following story of the fate of the P.B. Quadruplane. The P.B. or Supermarine twin engine Quadroplane (sic) was purposely crashed there at the far side of the aerodrome. The one in command said, “Potter I want you to see the crash vehicle is ready as is going to drop the Quadroplane (sic) this evening, the ambulance is also ready. ” Evidently they wanted to get rid of it. When he told me about it... he asked me not to mention it to anyone as whoever caused the crash might still be alive and might get into trouble.
  In his 1941 book, The Aeroplane of Tomorrow (Robert Hale Ltd, UK), Pemberton-Billing wrote that in 1916 I built the Nighthawk, a twin-engined patrol fighter to lie in wait for Zeppelins, which was provided with a searchlight and a gun turret and shell firing gun on the top, and was built as a quadruplane, enabling the very high aspect ratio and low wing loading necessary for a slow flying patrol, the wing loading being about 3 Ib./sq.ft., which enabled it to stand still in about a 28-m.p.h. breeze, although it had a top speed of 80 m.p.h. for overtaking Zeppelins.
  The late Jack Bruce always thought that the Night Hawk deserved more success, though perhaps it embodies too many clever gadgets all at once!

Specifications P.B.31 E
Source J.M. Bruce data M.G. Goodall data
Span upper wing 60 ft 60 ft 0 in
Span 2nd & 3rd wings 54 ft 4 in -
Span lower wing 57 ft -
Chord (top wing) - 4 ft 2 1/2 in
Length 36 ft 10 1/2 in 37 ft 0 in
Height 17 ft 8 1/2 in 17 ft 6 1/2 in
Areas Wings 962 ft2 962 ft2
Max Speed, mph 75 75
Landing Speed, mph - 38
Empty Weight, lbs 3,677 3,677
Loaded Weight, lbs 6,146 6,146
Endurance in hrs - 9
Engines 100-hp Anzani 100-hp Anzani
Supermarine PB31E Nighthawk 1388
The Supermarine Night Hawk was designed by Flt.Lt. Pemberton-Billing as an anti-Zeppelin interceptor and shared many attributes with the earlier P.B.29 that was designed for the same role. Both aircraft were twin-engine quadraplanes designed for long-endurance night patrols.The Night Hawk had a flexible 1 1/2-pounder Davis gun mounted above the cabin firing forward to attack the airship and two flexible Lewis guns, one aft the Davis gun and one in the nose, for defense. A searchlight was mounted in the nose to illuminate the target at night and secondarily illuminate the landing field at night. Powered by two 100 hp Anzani engines, the aircraft had the remarkable endurance of more than 18 hours.
The P.B.31E awaiting its delivery to Eastchurch. Without anyone standing near to the machine to give a size reference, the scale of the machine cannot be appreciated. The P.B.31E was flown only briefly before the inadequacy of its concept was accepted.
The Supermarine Night Hawk, 1388, at Woolston in 1917.
Members of the Pemberton Billing staff pose with the first P.B.31E in the works.
Side View of the "Night Hawk" Quadriplane, built experimentally by the Supermarine Company, to the designs of Flight-Lieut. N. Pemberton-Billing, R.N.
The P.B.31E in the company's Woolston works with a recoilless Davis gun installed in the gunner's cockpit atop the upper wing.
Front view of the P.B 31E showing the searchlight mounting and the air intakes for the 5-hp A.B.C. engine that drove the generator for the searchlight.
Supermarine PB31E Nighthawk 1388
Supermarine PB31E Nighthawk
Supermarine PB31E Nighthawk
Supermarine PB31E Nighthawk
Grain Griffin. N.100 with Sunbeam Arab engine, simple vee undercarriage, and plain broad-chord ailerons. Note the triangular logo "ECO RNAS GRAIN" under the tailplane. Photographed at Isle of Grain, March 1918. This machine served on HMS Vindictive in October 1918, and was written off after a crash while attached to this ship on W/E 12 December 1918.
Sage Type 4a trainer No. N116 on the occasion of its first flight on 17 May 1918. Delivered as a Type 4 to the Isle of Grain by rail in June 1917, it was powered by a 150-hp Hispano-Suiza engine. Wrecked on 24 July 1917, it was reconstructed with a Sunbeam Arab as the Type 4a. It went to Calshot as a reserve aircraft and survived until around June 1919.
The fifth production Blackburn-built Cuckoo N6954 dropping a torpedo off East Fortune 1919. Originally powered by a Hispano-Suiza, the Cuckoo was another aircraft that had to use the Arab due to the lack of Hispano-Suiza engines. Despite this, it continued in service with the RAF and the Japanese Navy after the end of the war. Its proposed replacements, the Short Shirl and Blackburn Blackburd, powered by Rolls-Royce Eagle VIII engines, could not meet the requirements for a torpedo aircraft.
The Dragonfly installed in a Sopwith Dragon.
Sopwith Dragon J3628 at McCook Field in the USA. McCook Field number P- is applied to the rudder. Note the fire extinguisher under the cockpit.
The Sopwith Snark utilised the triplane layout but did not have the excellent handling qualities of the earlier Sopwith Triplane. Note the Sopwith logos on the interplane struts.
The first Snapper, F7031, showing thai the smooth-lined crankcase cowling for the A.B.C. Dragonfly engine still left the greater part of each cylinder, with its prominent valve-gear, exposed.
F7031 was another Sopwith prototype for a high-altitude fighter that utilised the Dragonfly engine. The first of three, F7031 appeared at Brooklands in April 1919. If its engine had been successful it would have been a valuable addition to the RAF's fighter strength.
The Westland Wagtail

  In 1917 the Air Board issued their Type A.1(a) Specification for a light fighter with an engine of 50 hp more than the 130-hp Clerget rotary engine that was fitted to the Sopwith Camel. The specification stressed the need for a good all-round view for the pilot and armour behind the pilot. Oxygen equipment was to be installed as high-altitude fighting was part of the specification. The maximum speed was to be not less than 135 mph at 15,000 feet, with an armament of twin Vickers machine guns with 250 rounds of ammunition. It was hoped to produce a machine that would be faster than the Camel and, hopefully, as manoeuvrable. Westland, like Sopwith with their Snail and BAT with their F.K.23 Bantam, considered the A.B.C. 170-hp seven-cylinder air-cooled Wasp radial engine as the power plant for their proposed scout to meet the A.1(a) specification.
  Robert Bruce had wanted to design aircraft for Westland and with Arthur Davenport, as chief draughtsman, and W.A. Roiley, as the project designer, they built a small single-seat floatplane fighter for the Admiralty. The Westland N.1B was successful but the requirement lapsed when Sopwith Camels proved capable of being launched from capital ships. The Westland team had been working on the design of a light fighter since late 1917. Their design fitted the RAF specification and it was proceeded with as a private venture as the Westland Hornet according to surviving drawings, but emerged as the Wagtail when official names for aircraft were introduced in early 1918. It was proposed to power the fighter by the unproven A.B.C. Wasp seven-cylinder radial engine that promised 170-hp.
  At its meeting of 18 December 1917, the Air Board Technical Department discussed the requirements of Sir Douglas Haig for the Expeditionary Force (E.F.) in France for the coming year. Present were Sir William Weir, General Trenchard, General Salmond, Mr Gibson, the CTD (Controller Technical Dept) and the D/C TD (Deputy Controller Technical Dept). Sir William Weir noted that the choice of machines and engines for “bulk” production could not be made at the present time as the known machines did not come up to the requirements of the E.F. A “choice could only be made at present for development purposes.” Trenchard said the unless the 170 A.B.C. single-seater fighter could carry the full armament and petrol specified by the E.F. (Expeditionary Force) it would be of no use to the E.F. It was decided that a conference would be held between Weir, Generals Trenchard, Salmond and Pitcher to discuss the question of what types were to be adopted. The meeting then agreed to “the placing of an order with Messrs. Westland Aircraft Co., for three experimental single seater machines for 170 h.p. A.B.C. Engines to A.l.A. Specifications.” The Wagtail was in direct competition with the Sopwith Snail and BAT F.K.23 Bantam, all powered by the same A.B.C. engine. It was agreed that “We will continue pushing this design as an experiment.”
  At an earlier meeting on 20 November, the machines that were proposed for the A.B.C. engine were discussed. “The British Aerial Transport Co have built two types of machines, one with heavy loading one with light.” These were the F.K.22 and F.K.23 Bantam. “The small machine had started flying and gave promising results, but engine trouble occurred and trials must wait for the engines. Sopwith and Westlands both have machines designed and built waiting for engines. If this engine is got right a very handy machine with performance 5% superior to Type 1 may be possible.”
  It is usually stated that six Westland machines were ordered (C4290-C4295), but the order was reduced to three (C4291-C4293). However Minute 279/73 of the Air Board Technical Department’s 178th Meeting of 18 December 1917, recorded that an order be placed for only “three experimental fighter single seater machines for 170 h.p. A.B.C. Engines to A.I.A. Specifications” from Westland Aircraft Co. According to J.M. Bruce it is doubtful if C4290 was ever built as no reference to it has survived. It is considered that the previously published statement that six were initially ordered is false.
  A full-size mock-up was ready for inspection by the fortnight ending 9 January 1918, “and various questions of armament settled.” The first airframe was ready by the end of February, but the Wasp engine had not been received. Two other airframes were well advanced at this time. At a meeting on 31 December 1917, General Trenchard had stated that the “A.B.C. 170 H.P. engine should be ruled out as an engine for single-seater fighting machines; and that no further development should be made in connection with small fighters.” In the light of Trenchard’s disapproval is interesting that the development of these machines was continued. Given that they were more or less ready, it may have been thought that they would provide important information as experimental machines.
  The Wagtail was a small, neat looking biplane of conventional wood and fabric construction with constant chord equi-span wings. The fuselage was constructed around four square section spruce longerons and was of rectangular cross section for most of its length. It terminated in a vertical knife edge. The staggered horizontal and vertical spacer struts were tapered to fit into square cups welded to a wiring lug plate that were bolted to the longerons. To these fittings attached the swaged rods that cross braced the fuselage. Careful attention to detail meant that the metal fittings were for the most part identical. The flying-control assembly could be put together on a bench and dropped into the fuselage complete. The Wasp engine was mounted on a wire braced mounting ring with four attachment plates that connected to the inwardly curved extensions of the longerons. The engine was enclosed with metal top and side panels and a metal cowl through which the Wasp cylinders protruded. The rest of the fuselage was covered with fabric that had removable panels at the cockpit and forward fuselage.
  The tailplane and fin were of wooden construction with metal framed rudder and elevators, all being fabric covered.
  The inverted vee undercarriage struts were constructed of metal tubing with spruce fairings and the half axles were sprung with bungee rubber shock cord Sopwith fashion. 600 x 75 wheels were fitted. Shock was absorbed by bungee rubber shock cord. A curved moveable tailskid was mounted below the tailplane. The tailskid was steerable being mounted on a special skid post in front of the rudder post.
  The constant chord single bay wings were of conventional construction around two ash spars. The aerofoil was a “high efficiency” RAF 15 section. The wide centre section had a large cut-out above the cockpit and the trailing edge was cut back to the rear spar in order to provide the best possible pilot’s view as detailed hereunder. Constant chord ailerons were carried on both upper and lower wings. C4291 had a dorsal fin. Control wires ran inside the wings and fuselage except for the elevators.
  Armament comprised two synchronised Vickers .303 in machine guns mounted on top of the fuselage in front of the cockpit on steel brackets bolted to a wooden base. These guns “combined with the rapid manoeuvrability of the machine, make it a very dangerous enemy to tackle.” The chutes for the cases were low in the fuselage and were let into the fabric covering. 1,000 rounds of ammunition were provided and C4291 had provision for a Lewis gun to be mounted on the upper plane on a “special mounting designed to enable (the) gun to be rapidly lowered for loading purposes”. It appears that this gun was never mounted on the Wagtail. Ammunition was increased to 700 rounds per gun for the Wagtails that did not have the Lewis mounting. A 1.8 Aldis and a 3” ring and bead sights were fitted. A hole was provided in the starboard side of the windscreen for the Aldis sight eyepiece. Oxygen was provided for the pilot. Two petrol tanks were fitted, one under the pilot’s seat of 11-gallon capacity, and a 15 gallon one between the pilot and engine back plate above the pilot’s legs. The tanks had a total capacity of 20 gallons. A two-gallon oil tank was also fitted.
  The Wagtail emerged as a compact aeroplane of pleasing lines. Great care had been taken to make for ease of construction. The majority of the fuselage fittings were identical, that, combined with the small number of machined parts, and the fact that the fuselage, chassis and wing attachments could be turned out as stampings, would “greatly facilitate rapid production.”
  A mock-up of the “Westland. A.B.C. Wasp” was inspected around the New Year and “various questions of armament settled.”
  The fortnightly Reports of the Technical Dept (T.6 - Design Branch) titled Aircraft Production Experimental Aircraft range from January 1918 to January 1919, and give a fortnightly account of the progress of experimental designs up to the Armistice, after which the reporting period was different. From these reports one can chart the progress from concept to a machine selected for production or rejection. With respect to the Wagtail the following sequence is recorded:
  F/E 23.01.18. Westland A.B.C. Scout. Contract for three machines.
   First machine now ready for engine, delivery of which is promised for 31st inst. Details of arrangements of guns, etc., have been settled, machine should be flying 10 days after receipt of engine. Strength calculations are in hand.
  F/E 06.03.18. Westland Type B.N.1 “Wagtail” Wasp. First machine. Complete and awaiting engine which is promised 07.03.18.
  F/E 20.03.18. Wagtail.
   First machine. Complete and ready for engine which is now promised for 20.03.18.
   Second machine. Now being erected.
   Third machine. The centre section of this machine is being lowered by 6 in. in order to reduce the blind area. Stability being investigated.
  F/E 03.04.18. Wagtail
   First machine. Complete and ready for engine which is now promised for 09.04.18.
   Second machine. With top plane lowered to give better visibility now being erected.
   Third machine. Now being erected.
  F/E 01.05.18. Wagtail.
   First machine. Complete and awaiting new engine which is promised for 01.05.18. The first engine broke down and cylinders were returned to the makers for repair. The engine has now been transferred to the second machine.
   Second machine. Commenced maker’s trials 29.04.18. and is ready to go to Martlesham for tests.
   Third machine. Fuselage complete. Controls, instruments, etc., fitted. Planes being assembled.
   Design completely passed for strength.
  F/E 12.06.18 to F/E 21.08.18. Sopwith Snail, BAT Bantam and Westland Wagtail. Wasp. Trials suspended until engine troubles have been overcome.
  F/E 04.09.18 to 16.10.18. Sopwith Snail, BAT Bantam and Westland Wagtail. Wasp. Trials suspended during development of the engine.
  F/E 30.10.18. Sopwith Snail, BAT Bantam and Westland Wagtail. Wasp. Trials suspended as engine will not be put into production. F/E 13.11.18. Sopwith Snail, BAT Bantam and Westland Wagtail. Wasp.
   Snail Contact cancelled.
   BAT Bantam Contract to be completed.
   Westland Wagtail Wasp. Contract completed.

  One of the RAF’s requirements for the Wasp powered fighter was a maximum all-round view. The Wagtail originally had a wide-span upper centre section that had a large semi-circular cut out in its trailing edge in order to give the pilot a good view. The fin extended well in front of the tailplane. Both the upper and lower wings had 2 1/2° dihedral. Capt F. Alexander was attached to the Westland Company to test fly the Wagtail. Before flight testing commenced Alexander suggested that the opening in the upper wing centre section be made larger based on his operational experience. On the redesigned centre section, the cut-out was made larger between the spars by removing the central three ribs giving an almost full width opening between the front and rear spars. The trailing edge was also dramatically cut back to the rear spar. This centre-section was fitted to C4293 as a trial and was mounted six inches lower. In order to use the same interplane struts and bracing wires the wings were re-rigged with the upper having a dihedral of 5° while the lower had no dihedral. This was to be standard for the type.
  The first flight took place in April 1918, and it is assumed that this was C4291 with equal dihedral on both wings as there was not enough time to modify this machine. Alexander was so taken with the Wagtail’s performance that he executed a loop on the maiden flight. The fin was reduced in size to approximately half of its length, as there was insufficient rudder area. Apparently when side-slipped there was insufficient rudder to overcome the nose-down effect of the fin. It was thought that this would suffice rather than building a new rudder. It appears that the modification was successful.
  Engine problems saw the cylinders returned to the manufacturer. When the Wasp engine was returned to Yeovil it was fitted to a Wagtail with the modified centre section. J.M. Bruce contends that this was C4293 that arrived at Farnborough from Martlesham Heath on 27 May 1918. According to D.N. James the engine was mounted in the second prototype, C4292, that had the modified centre section and wings and was nearer to completion. This seems unlikely given that the modifications were carried out on C4293 as recorded in the fortnightly reports as noted above. Whichever was the actual machine that was given the engine, testing of the Wagtail resumed on 29 April.
  Unfortunately, C4292 was damaged in a fire when one of the ground crew tried to prove you could extinguish a cigarette in a can of petrol! According to Capt A.R. Boree, who carried out the trials of the first D.H.9A built by Westlands, a Wagtail was damaged in a canvas Bessoneaux hangar fire at Yoevil. Boree noted that there was lax discipline with the ground staff and he complained about the civilian staff pouring petrol into his machine while smoking. In order to demonstrate it was safe this individual put a lighted cigarette into a can of petrol. On this occasion it did not explode, however Boree was later told that this individual tried this trick again and it resulted in a hangar fire that burnt out the Wagtail. Whatever the truth, C4292 was completed and survived until at least 1920 when it still had the Wasp engine.
  According to James the arrival of two more Wasp engines enabled the third prototype to be completed, flying in early March. The fortnightly report for 1 May 1918, notes that the third machine was not yet ready. On 8 May C4293 was flown to Martlesham Heath for trials with the Aircraft Experimental Establishment with different airscrews. On 18th the machine made a bad landing on broken ground suffering damage when it nosed over, damaging the engine and undercarriage. After repairs C4293 was transferred to the Royal Aircraft Factory (soon to be the Royal Aircraft Establishment - RAE) for investigation into the problems with the Wasp engine. Two weeks later all trials of Wasp powered aircraft, the Wagtail, Sopwith Snail and BAT Bantam, were terminated. C4293 had only made four brief flights at Farnborough on 27, 28 and 29 May 1918. The Wasp production program was cancelled in late October 1918 as its problems were seen to be insurmountable.
  In May 1918, the Aeroplane Experimental Station, Martlesham Heath reported that it was testing the experimental Sopwith Snail, Westland Wagtail and BAT Bantam against the performance of the Sopwith F.1 110-hp Le Rhone Camel. The three Wasp powered scouts were also flown against the Martinsyde F.3 in mock combat.
  W.H.K. Copeland, a Flight Commander with No.60 Squadron, tested the Wagtail at Martlesham Heath, and provided the following report on the machine: The Wagtail as a fighting scout is extremely satisfactory. Its performance is good and will probably be greatly improved when the engines are running better.
  The visibility of this machine is excellent, and the few blind spots are overcome by its manoeuribility (sic), which is better than that of a Camel, being quicker on turns, and following controls immediately. The guns are in a very good position in front of the pilot on top of the fuselage and are easy to get at for the clearing of stoppages. All instruments are easily seen and all controls conveniently placed except the air cock on bottom of hand pump, which cannot easily be reached when strapped in.
  When fully clothed the pilot is quite comfortable. Nothing fouls his arms, but at present his feet foul the top of the petrol tank and footboards.
  The machine is easy to land and the landing speed is low.

  In the notes accompanying this report the following comments were made:
  There were two petrol tanks, one between the pilot and engine back plate above the pilot’s legs and one under the pilot’s seat. A pressure petrol supply system was employed.
  The cockpit was comfortable when fully clothed, but toes fouled the front tank and heels the floor boards. It was notes that the CC gear was not yet fitted.
  It was considered that the pilot could crawl out in the event of a turn-over.
  The tailplane was adjustable on the ground only.
  The tail skid was steerable.
  The landing speed was slow and it was easy to land.
  The guns were easy to access for stripping down and cleaning.
  Copeland noted under “fouling” that the CC gear had not yet been fitted. It is presumed that therefore this gear may have caused fouling in other installations and was a consideration that had to be taken into account.
  The Wagtail was flown in a mock fight against the Martinsyde F.3.
  This fight was started about 4000 feet and ended up at about 1000 feet, the Martinsyde forcing the Wagtail down. On trying to get on each others tail, the Wagtail appeared to turn slightly quicker, but the Martinsyde could easily out climb it on turns thus having the advantage of height. The Wagtail came off banks, if anything quicker. The Martinsyde could have broken of (sic) the fight any time and got away but not so with the Wagtail. There is no mention of the Wagtail being flown against the BAT Bantam or Sopwith Snail, the other two contenders for the Wasp powered fighter specification, nor against the Sopwith Camel. A report was furnished of the Martinsyde flown against the Camel, and the Snail against the Camel, and, as recorded above, the Wagtail against the Martinsyde.
  C4291 had been re-engined and modified to “standard” before it went to Farnborough during the summer and flow there during the autumn of 1918 presumably in the attempts to make the Wasp a reliable engine.
  RAE Report K1360 of October 1918 reveals that C4291 was at the RAE for “Wasp engine development work.” After only one hour in flight it was found necessary to make several modifications to the aircraft.
  Considerable vibration was observed throughout the wing system during flight, and an examination was made after landing. The condition of the attachments of the plate supporting the engine and also the fastenings of the wing spars to the fuselage was found to be such that the aeroplane was dismantled.

Inspection of the wings showed

  Elongation of some of the bolts through the wing spars at the points of attachment to the centre sections. The stringers, which are of extremely light construction had bent so badly as to be no longer of any value and had broken at several points. This failure of the stringers was partially due to the bending of the compression rib at the fuselage end of the wings. This compression rib is of light construction and had deflected under the pull of the doped fabric and put end load on the stringers. If these stringers are to be of any value they should be stiffened considerably. The compression ribs are stiffened by struts at intervals, but none of these struts had been glued in position and some had not been fastened in any way but were pressed in tight between the flanges. The others were fastened with small nails through the flanges. In these circumstances the value of these struts and stiffeners was very limited.
  The construction of the wings was further criticised. The spars were spindled out to a point very close to the end leaving a very small margin around the bolt hole for the bolt attaching the wings to the fuselage. There were two bolts at this point, one vertically for the wing attachment, the other horizontally to take the internal bracing wires. The small margin made it difficult to bush the holes in case they become elongated and “so leads to unnecessary scrapping of wings.”
  In order to overcome these difficulties and continue with flying as soon as possible a number of modifications were made to the machine. The spindling of the spars was filled in for about five inches using carefully glued blocks of wood. The internal structure of the wings was strengthened.
  The cross members at the rear of the engine bearer plate were made of spruce and the ends were found to be split and the bolt holes elongated. These were remade in ash and fitted with a strengthened bearer plate with modified stays fitted.
  On 6 November C4291 was transferred to the Aircraft Armament and Gunnery Experimental Establishment at Orfordness for gun firing trials. E.R. It was here that Eugene R. Macdonald flew the Wagtail for the first time on 9 November. “Ripping machine” was his Log Book comment. He flew the machine again on 13 & 20 November and 9 December.
  Despite the end of the war and the cancellation of the Wasp engine the rebuilt C4292 ended up at Martlesham Heath on 29 January 1919, where it remained until at least 1920 when it was still powered by a Wasp engine.
  US Navy personnel visited the RAF Test Station at Martlesham Heath early in 1920 and reported on the testing methods in use there and on the latest fighting aircraft that were present. With respect to the single-seaters fitted with the A.B.C. Dragonfly they recorded the Westland Biplane, BST Basilisk, Nieuport “Night Hawke” and Siddeley Siskin, Sopwith Snark, Sopwith Dragon and the 300 hp Hispano powered Martinsyde. The Westland referred to would have been a Wagtail. This was reported to having a “Moderate performance - Excellent on controls - Very good visibility.”
  The faults of the Wasp engine meant that there was no hope of the Wagtail going into production. What was not appreciated at the time was that the emphasis placed on a good pilot’s view that had led to the huge holes in the centre section actually caused eddying end losses and gave a lift distribution much less that a continuous wing. Later fighters, such as the Hawker Fury and Gloster Gladiator, had a good view for the pilot without the sacrifice of the centre section.
  The Wagtail did not make the list of RAF Peace Establishment Type Machines of 25 November 1918, however in 1920 two more Wagtails were ordered. Powered by a 150 hp Armstrong Siddeley Lynx seven-cylinder air cooled radial, J6581 and J6582, featured a shorted fuselage wherein the bay aft the engine was removed to compensate for the weight of the heavier Lynx. The rudder was a comma shape and the duo had a strengthened undercarriage. They were flown to about 1922. Some records indicate that at least one was fitted with the Wasp II engine. A.B.C. had persevered with development of the Wasp engine and the 200-hp Wasp II was developed.
  Report No.K.1682137 noted that J6591 was fitted with Lynx No. A.S.1/26480, and J6582 with No. A.S.4/26483. The difference between the Wasp and Lynx powered Wagtail was 258 lbs and “an increase in weight such as this on a small scout is extremely serious, so much so that it has been impossible to fly the Wagtail with Lynx engine in anything but an unloaded state. With full military load it would not only be below strength, but might also begin to show difficulties of control in the air.”

Weights in lbs
Wasp Lynx
Empty 832 Empty 1078
Petrol 30 gal 173 Petrol 173
Oil 2 1/2 gal 25 Oil 3 3/4 gal 37
Military load 335 Military load 333
Total 1365 Total 1623
Source: TNA AVIA 6/4232.

  With respect to flying qualities the machine was described as “straight forward to handle in the air. Though sensitive, it does not seem so controllable as the Bat Bantam with Wasp engine. It is very quick on the ailerons, but in flight the rudder and ailerons are less simple to coordinate than in the Bat Bantam, and hence cannot be made to produce the rapidity of manoeuvre that is characteristic of the Bat.”
  From what I remember of the Wagtail with Wasp engine, I think that the installation of the Lynx engine has produced a distinct deterioration of control; from which it may be inferred that if the aeroplane were loaded up to 1600 lbs. its controllability would deteriorate still further, especially at low speeds.
  Under the heading Getting Off the following comments were made:
  A noticeable feature is the marked turning tendency to starboard with the engine on. When the pilot is getting off, this turning tendency develops suddenly as the wheels leave the ground. The aeroplane should be allowed a full run and taken off carefully. It cannot be lifted into the air like a Sopwith Camel or Pup, neither does it jump into the air like a Bat. In this respect it shows the Nighthawk characteristics, only somewhat exaggerated. It is therefore difficult to take off down wind, and if pulled off the ground too soon is inclined to drop its starboard wing suddenly, and bump one wheel on the ground.
  The machine was comparatively easy to land although some pilots thought that it was difficult to get enough up movement on the elevator to make a good tail down landing, “but opinion is divided on this point.” The wagtail sank rapidly when glided down slowly. It was “extremely harsh” on the tail skid.
  With the Lynx engine the aeroplane was slightly nose heavy “which spoils the perfect sense of controllability which a pilot should feel with such a small scout.”
  With the engine full on the machine required a considerable amount of port rudder, although the force necessary to neutralise the turning force was never large. The view was excellent.
  Stability was “about neutral” longitudinally. While the machine had a fixed tail the amount of elevator to trim the machine at any speed was small. Laterally it was considered to be below the standard for a scout of this design, but control was good enough to prevent the pilot experiencing any difficulty in flying due to it, except in getting off when a wing dropped.
  The aeroplane is extremely steady at all speeds in the air and there is little vibration due to the engine or other causes. It is also steady side-slipping or rolling, and feels comfortable when being dived or violently manoeuvred.
  The cockpit was criticised as small and when the ammunition trays were fitted, they fouled the pilot’s legs. The control stick could not be moved forward with the hand at the top as the clearance between the stick and the dashboard was small. The stick was shortened two inches and the instrument board raised slightly to clear the oil tank and ammunition boxes. Another modification was the fitting of an additional back rest for the pilot.
  The wing struts on both Wagtails bowed so badly that they had to be replaced. It was found that while they had been erected as marked, this was incorrect and they were reversed. Their bases were splayed to allow for the dihedral and they were bottoming on only one side. “As they were incorrectly marked this error could not have been discovered without dismantling the struts, the position of which according to their markings was correct.”
  The Wagtail was the best of the three Wasp powered fighters. Test pilot Major Oliver Stewart, MC, AFC, found the Wagtail to be one of the most perfect flying machines ever produced. The Sopwith Snail had a similar performance but had other problems. The BAT Bantam was inferior on the climb and also had dangerous spinning characteristics. If the Wasp had proved to have been able to produce the horsepower to weight that it promised, then the Wagtail would have had a chance of meeting the specifications and been introduced as the first light weight fighter of the RAF. Unfortunately, like all the aircraft designed for the A.B.C. Wasp and Dragonfly engines, the Wagtail was let down by the engine and had no hope of production.
  Westland apparently tried to market the Wagtail and Weasel overseas in 1920 which would explain the dual French/English booklet mentioned in the bibliography. Again, they had no success.

Comparison between "Bantam" "Snail" and "Wagtail."
Climb Bantam Snail Wac tail
Height in ft Time RofC Time RofC Time RofC
5,000 3.75 1165 3.7 1235 3.5 1300
10,000 8.9 805 8.25 960 7.8 995
15,000 17.3 440 14.4 690 13.9 690
17,000 - - 17.6 580 17.1 560
Speed @15,000 ft 111 mph 127 mph (1) 117 mph (1)
Pilot, lbs 180 180 180
Vickers guns, lbs 70 70 70
Deadweight, lbs 103 (2) 115 115
Fully Loaded, lbs 1,333 1,396 1,326
Notes: (1) Doubtful. (2) The deadweight is less as the wing structure was considered to be reducible by 20 lbs. Source: TNA AIR1/1153/204/5/2407

Westland Wagtail Specifications
Source 1.C4291 2. & 3. 7. 4. 8. 5. 6. Lynx
Span 23 ft 2 in 23 ft 2 in 23 ft 2 in 23 ft 2 in - - -
Length 18 ft 7 1/2 in 18 ft 11 in 18 ft 11 in 18 ft 11 in - - -
Height overall 8 ft 0 in 8 ft 0 in 8 ft 0 in 8 ft 0 in - - -
Gap 4 ft 6 in 4 ft 0 in to 4 ft 6 in - 4 ft 11 in 4 ft 11 in - 4 ft 11 in
Chord 4 ft 6 in 4 ft 6 in 4 ft 6 in 4 ft 6 in - - -
Stagger 1 ft 6 in 1 ft 6 in 1 ft 3 1/2 in 1 ft 6 in - - -
Incidence 2° 2° 2° 2° - - -
Top plane 2 1/2° 5° 5° 5° - - -
Lower plane 2 1/2° 0° 0° 0° - - -
Prop diameter - 8 fit 6 in 2,590 mm - - - -
Track - - - 4 ft 8 in - - -
Span tailplane 9 ft 0 in - 7 ft 10 3/4 in - - - -
Area in ft2
Tailplane - 15.4 - - - - -
Elevators - 9.5 9.5 - - - -
Fin - 2.1 2.1 - - - -
Rudder - 4.5 4.4 - - - -
Main planes (inc ailerons) 190 190 190 - - - -
Ailerons (each) 6 5.8 6 - - - -
Petrol, gallons - 26 26 - - - -
Oil, gallons - 3 3 - - - -
Weights in lbs
Empty - - 746 746 832 832 1078
Pilot - - 180 - 180 - -
Armament & 1,000 rounds - - 160 - - - -
2 Vickers - - - - 70 - -
(Bags) - - - - 85 - -
Oxygen - - 25 - - - -
Petrol 20 gall - - - - - 173 173
Petrol 24 gall - - - - 173 - -
Oil - - - - 25 25 37
Petrol & Oil - - 219 - - - -
Military load - - - - - 335 335
Total 1,330 1,330 1,330 - 1,365 1,623
Climb to
5,000 ft - 3min 5 sec 3 1/2 min - - - -
10,000 ft - 7 min 8 sec 7 1/2 min - 9 min 50 - -
15,000 ft - 13 min 9 sec - - 18 min 10 - -
17,000 ft - 17 min 1 sec 17 min - - - -
Speed in mph
At 10,000 ft - - - - 121 - -
At 15,000 ft - 117 - - 113 - -
  1. Aeroplane Data Book.
  2. Westland Aircraft - The Weasel, The Wagtail, Westland Aircraft.
  3. Ballam, F & Gibbings, D. Westland Aircraft 1915-1926, (the Westlands Aircraft Collection Vol.1).
  4. The Book of Westland Aircraft.
  5 & 6. TNA AVIA 6/4232.
  7. Janes All the World’s Aircraft, 1919 Edition.
  8. TNA AVIA 6/5156. Report No. E.2324 on C4291.

Westland Wagtail Specifications (continued)
Source 1.C4291 2. &3. 7. 4. 8. 5. 6. Lynx

Westland Wagtail C4291
Westland Wagtail C4293
Westland Wagtail J.6582
Westland Wagtail. The Wagtail in its original form, with high centre-section and equal dihedral on upper and lower wings.
In its modified form with a reduced area fin, this Wagtail has constant-chord equal dihedral wings but with a small curved centre-section cutout.
C4291, the first Wagtail had the same dihedral on the top and bottom wings. Note the aircraft with the large spinner in the background, (via A Revell)
C4292, the second and all subsequent Wagtail fighters, had double dihedral on the upper wing and none on the lower wing to improve stability and handling. The cut-out in the centre section has been enlarged to improve the pilot's upward view.
C4293 with Wasp I installed has been placed in a fictitious landscape in this Westland advertisement.
C4293 with Dragonfly engine.
Modified Wagtail with increased dihedral on upper wing, flat lower wing, and enlarged cut-out in centre-section.
One of the two short fuselage Wagtails ordered in 1929. It has an Armstrong Siddeley Lynx engine, curved fin and much enlarged centre-section cutout.
This is one of the two Westland Wagtails (J6581/ J6582) built specifically in 1921 for use as a testbed for the new Armstrong-Siddeley Lynx I. This machine had a different nose (owing to the mounting of the Lynx-engine) from the three Wagtails built in WW1 with the A.B.C. Wasp engine. Also the undercarriage was modified as was the tail which in these 1921 machines was more Sopwith-like.
The second version of the Wagtail with a 160-hp Armstrong-Whitworth Lynx engine circa 1921. A strengthened undercarriage was fitted to these two machines.
J6582 was the second of the Lynx powered Wagtails. Photographed at Lympne shows the revised fin and rudder of this version.
The construction of C4291 followed conventional lines. Armament was twin Vickers guns.
Wagtail C4293 after its heavy landing on 8 May, 1918. during 'fighter trials' at Martlesham Heath.
Westland Wagtail
No. 9004 with a Breguet in the background.
Posing with a dark coloured "P.B. Scout", however photographs of the P.B.25 with armament have yet to appear.