A.Jackson De Havilland Aircraft since 1909 (Putnam)

De Havilland D.H.9A

   By the end of 1917 the demand for Rolls-Royce Eagle VIII engines exceeded the supply to such an extent that orders were placed in America for large numbers of 400 h.p. Liberty 12s. These were earmarked for a new day bomber based on the D.H.9 but the Aircraft Manufacturing Co. Ltd., was at that time engaged on building the D.H. 10 so that the extensive re-design of the earlier type was entrusted to the Westland Aircraft Works at Yeovil, Somerset. Assisted by Mr. John Johnson, specially loaned for the purpose by Airco, the Westland design team, already experienced in building the D.H.4 and D.H.9, not only took full advantage of the extra power of the Liberty but also combined the best features of both these designs to create the outstanding strategic bombing aeroplane of the War. The fuselage was strengthened to take the heavier engine mainly by replacing the plywood partitions of the D.H.9 by wire cross bracing, while an improvement in climb and ceiling was ensured by fitting mainplanes of increased span and chord.
   The new machine was designated D.H.9A, the prototype of which was a modified Westland built D.H.9, B7664, fitted with a Rolls-Royce Eagle VIII to enable flight trials to proceed while awaiting delivery of the Liberty engines. A second Eagle powered example, C6350, was also used, this being a Hendon built D.H.9 converted by Airco. Representatives of the Packard Motor Company, manufacturers of the Liberty, came to England to supervise its installation in production D.H.9As, the first of which was C6122 and by December 1918, 885 had been built by Westland and other contractors. Armament consisted of one forward firing Vickers gun on the port side of the front fuselage, single or double Lewis guns on a Scarff ring on the rear cockpit and up to 660 lb. of bombs carried on external racks under the fuselage and lower mainplanes.
   Many D.H.9As were flight tested at Yeovil by Harry Hawker and the first squadron arrived in France on August 31, 1918. This was No. 110 which flew aircraft presented by the Nizam of Hyderabad, carried inscriptions to that effect and dropped some 10} tons of bombs in daylight raids on Coblenz, Frankfurt, Mannheim and other German industrial centres. The D.H.9A also formed the new equipment of several other squadrons on the Western Front and of Nos. 47 and 221 Squadrons which fought the Bolsheviks in Russia, where replicas were later built as the type R-1 powered by the M-5, an engine of local manufacture copied from the Liberty.
   As in the case of the D.H.9, two Airco-built D.H.9As (one being E8449) were sent to America where it was planned to build 4,000. The Armistice terminated this project but four prototypes were built, two by the Engineering Division of the Army's Bureau of Aircraft Production and two by Dayton-Wright. Completed in August 1918, they were designated USD-9 but their dimensions alone show that they were copies of the D.H.9A and not of the D.H.9. In October 1918 Dayton-Wright delivered four examples of a modified version known as the USD-9A which had the pilot's Browning gun on the starboard side and was fitted with a more rounded rudder. In the following month five more USD-9 As were produced by the Engineering Division which in February 1919 converted one of them to USD-9B with 435 h.p. Liberty 12A and wings of increased area. Another of these aircraft, serial A.SAO 118, was a single seater experimentally fitted with a pilot's compartment of riveted steel plates and is believed to be the first machine ever to fly with a pressurized cockpit. The conversion was made at McCook Field, Dayton, Ohio in 1920 by the Engineering Division and was first flown by 'Art' Smith, a civilian test pilot, on June 8, 1921. Pressurisation was effected by a propeller driven pump on the port lower mainplane and the instrument panel was positioned on the trailing edge on the top centre section. The career of the USD-9A ended in 1922 when two examples appeared as the Ordnance IL-1 infantry liaison type at an all-up weight of 5,686 lb. It was of grotesque appearance having triple instead of double interplane and undercarriage struts.
   After the war the D.H.9A continued in production in the United Kingdom and several hundred were built for Regular and Auxiliary day bomber squadrons at home, for Flying Training Schools and for squadrons stationed in the Near and Middle Easts. From June 23, 1921, D.H.9As of Nos. 30 and 47 Squadrons were used on the regular Cairo-Baghdad mail service. Long term contracts were placed with Westland and de Havilland under Specification 45 22 for reconditioning D.H.9As, and the type remained standard equipment for 13 years, until struck off charge in 1931. During that time it formed the initial equipment of the newly formed Auxiliary Squadrons and under the nickname 'Ninak' became familiar to the man-in-the-street for its inspiring displays of wing drill at Hendon Pageants and its battle formations during the 'Redland' versus 'Blueland' manoeuvres staged annually by the R.A.F. in those days.
   In Iraq and on the North West Frontier the tropicalised D.H.9A became a general purpose aircraft equipped with an additional radiator under the nose and an overload fuel tank under the starboard upper mainplane. It was engaged mainly on policing duties and when working over difficult terrain, far from regular lines of communication, often carried spare wheels, goatskins of water, or tents and bedding on the sides of the fuselage or between the undercarriage struts. One aircraft, placed at the disposal of the Portuguese long distance pilot Major Brito Paia to replace his wrecked Breguet, left Lahore on May 30, 1924 fitted as a three seater en route to Macao, but crashed near Hongkong on June 20th. Between October 27, 1925 and November 1 st, three others flew from Cairo to Kano, Nigeria, piloted by Sqn. Ldr. Coningham, and F/Lts. Baggs and Rowley. Some D.H.9As were converted for target towing or as dual trainers, and in 1929 J8177 became the personal aircraft of A. V.M. Sir Robert Brooke-Popham, A.O.C. Iraq.
   Australia and Canada received the type in 1920 as part of the Imperial Gift, but most of the 29 sent to Australia remained crated until commissioned by the Royal Australian Air Force under the type serial A1 in 1925. After modification by the Whitehead Aviation Company, all 11 Canadian D.H.9As were handed over to the Air Board Civil Operations Branch for forestry patrol and survey work alongside the D.H.4s. Between October 11-17, 1920 three of them took part in the first trans-Canada flight, each covering one leg of the Winnipeg-Vancouver section, piloted respectively by F Lts. J. B. Home-Hay. C. W. Cudemore (G-CYAJ) and G. Thompson (G-CYBF). In 1922 six were at Camp Borden and the remainder were on photographic survey work on wheel or ski undercarriages at Rockcliffe, but the majority were destroyed in a hangar fire at Camp Borden on October 16, 1923.
   Successful development of the 450 h.p. Napier Lion engine, first flown in 1918 in a D.H.9, led to a prototype, E775, and ten production installations, E746, E748-50, E752-57, being made in new Whitehead-built D.H.9A airframes by the R.A.E., at Farnborough. Although of broad arrow configuration, the Lion fitted snugly into close fitting cowlings and was cooled by an underslung retractable radiator designed and constructed at the R.A.E., which also made the airscrew. After prototype trials with E775 in April 1919, the first production aircraft, actually E748, was completed with large mail boxes under the lower mainplane and first flown on July 18th. The boxes were fitted to several others but were subsequently removed and the rear cockpits enlarged for the internal stowage of mail bags. E775 was also tested in September 1919 with a Lion II giving 465 h.p. and during the following month six of the other aircraft were stripped of military equipment and delivered by air to Aircraft Transport and Travel Ltd. at Hendon for use on the air mail service to the Army of Occupation on the Rhine. This service, begun by the R.A.F. with D"H.4S and D.H.9s on December 16. 1918. was handed over to civilian operation on August 15, 1919 and the Lion powered D.H.9A. with its high performance, made winter flying possible over the most difficult stage through the Ardennes. All six aircraft returned to the R.A.F. between April and June 1920 and in the following year one of them, E752, made deck landing trials on H.M. Aircraft Carrier Eagle even though not fitted with arrester hooks. E746 made full load trials at Farnborough with the Lion II in 1920 and E748, with Lion II and 14 ft. 6 in. wide-track undercarriage, was delivered to Gosport on August 10, 1921. Another Lion II D.H.9A, ?775, fitted with experimental folding wings, first flew at Farnborough on January 22, 1924 and was delivered to Gosport for carrier trials on March 29.
   The D.H.9R sesquiplane racer erected from D.H.9A components by the Aircraft Manufacturing Co. Ltd. was also Lion powered. Test pilot Gerald Gathergood made a fast trip from Hendon to Amsterdam in this machine in 2 hours 10 minutes to attend the ELTA Exhibition in July 1919 and while there won the 137 mile closed circuit race at an average speed of 145 m.p.h. During September comparative trials were made against the D.H.4R and when the aircraft flew side by side, the much cruder D. H 4R proved to be marginally faster. On November 15th, Gathergood and the D.H.9R broke several British speed records at Hendon, and raised the closed circuit speed to 149-43 m.p.h.
   So vast were the stocks of D.H.9A major assemblies and so limited the Air Ministry's financial resources, that contracts were three times awarded to the Westland Aircraft Works for aircraft using the maximum number of D.H.9A components. The first, signed in 1920 was for 36 Westland Walrus fleet spotters, with Lion engines and unstaggered wings, heavily encumbered with grotesque naval excrescences. The Walrus was developed from an earlier prototype, the Tadpole J6585 built by Armstrong Whitworth from D.H.9A components, including the Liberty power plant. In 1924 a small batch of somewhat similar Lion powered general purpose D.H.9As was ordered and the third contract, awarded in 1926, was for the quantity production of the Westland Wapiti with Bristol Jupiter engine. The final D.H.9A derivative, .77026', known as the D.H.9AJ Stag, although designed for the Lion engine was also completed with a Bristol Jupiter and first flown at Stag Lane by Hubert Broad for 40 minutes on June 15, 1926. It crashed at Martlesham during trials but was rebuilt by de Havillands and flew again on December 24, returning to Martlesham in February 1927. It was unsuccessful as a D.H.9A replacement but donated its engine to the prototype Westland Wapiti and its new-style oleo undercarriage to squadron D.H.9As as they came up for modernisation.
   In the purely experimental sphere, a Westland built D.H.9A numbered F1632 was denuded of its mainplanes by Handley Page Ltd. in 1921 and fitted with a thick section cantilever monoplane wing bolted to a small cabane on top of the fuselage. Designated H.P.20, it completed the practical tests begun with a modified D.H.9, H9140, on a full span, controllable slots, achieving a landing speed as low as 43 m.p.h. at a wing loading of 11 lb./sq. ft., representing a lift coefficient of IT7. Another experimental aircraft was Liberty engined E870, which with Westland-built J6957 (Lion II), was used by the R.A.E. for tests on steel airscrews in May 1924. E865 took part in similar tests on Fairey-Reed duralumin airscrews in April 1925 and E8444 was used for immersion tests at Felixstowe. In 1933 D.H.9A H3588 was used at Farnborough for flight testing the aircooled Liberty 12 engine and in the same year E9895 was fitted at Brooklands with an experimental Vickers long stroke oleo undercarriage. Another served as tanker in flight refuelling experiments with a Vickers Virginia over Farnborough in January 1931.
   Because of its long R.A.F. service the D.H.9A figured less prominently on the secondhand market than did the D.H.9. A few brand new aircraft were taken over from F. W. Berwick and Co. Ltd. by the Aircraft Disposal Co. Ltd., six of which were civilianised at Croydon for racing or overseas demonstration. The first, G-EAXC, converted in 1922, made fastest time in the race for the Coupe Lamblin over the course Le Bourget-Brussels-Croydon-Le Bourget piloted by Rex Stocken. A second conversion, G-EBCG, appeared in 1922 fitted with a 350 h.p. Rolls-Royce Eagle VIII for participation in the Croydon Whitsun Races. For the first King's Cup Race which started at Croydon on September 8, 1922 the nose radiator was removed in favour of small side radiators. This type of Eagle conversion was made originally to the military demonstrator G-EBAN, which, fitted with Lamblin radiators between the undercarriage legs, left for Madrid in February 1922 to take part in trials before Spanish Government officials, which led to an order for a batch of similar machines for the Spanish Air Force.
   To enable the A.D.C. test pilot H. H. Perry to compete against Cobham's Lion engined D.H.9 in the King's Cup Race of July 12, 1923, John Kenworthy modified one of the Aircraft Disposal Company's D.H.9As G-EBGX to take the Lion. After a period of bad luck during which over zealous helpers broke the airscrew at Hendon on the morning of the race and F. T. Courtney forced landed at Brooklands during the Aerial Derby on August 6th, GX was disposed of overseas.
   The D.H.9A F1010, displayed at the R.A.F. Museum, Hendon, was captured by the Germans during the First World War and exhibited at the Berlin Air Museum. Only the fuselage remained when it was recovered from Krakow, Poland, in 1980, with new wings and other components being built at the Cardington workshops. Its Liberty engine was obtained from the U.S.A.

SPECIFICATION AND DATA
   Manufacturers:
   The Aircraft Manufacturing Co. Ltd., Hendon, London, N.W.9
   F. W. Berwick and Co. Ltd., Park Royal, London, N.W.10
   Gloucestershire Aircraft Co. Ltd., Sunningend Works, Glos.
   Handley Page Ltd., Cricklewood Aerodrome, London, N.W.2
   H. G. Hawker Engineering Co. Ltd., Canbury Park Road, Kingston-on-Thames and Brooklands Aerodrome, Byfteet, Surrey
   Mann, Egerton and Co. Ltd., Aylsham Road, Norwich, Norfolk
   George Parnall and Co. Ltd., Yate Aerodrome, Glos.
   S. E. Saunders Ltd., East Cowes, Isle of Wight
   Short Bros. (Rochester and Bedford) Ltd., Rochester, Kent
   The Vulcan Motor and Engineering Co. Ltd., Southport, Lanes.
   Westland Aircraft Works, Yeovil, Somerset
   Whitehead Aircraft Co. Ltd., Townshend Road, Richmond, Surrey
   The Dayton-Wright Airplane Co., Dayton, Ohio, U.S.A.
   The Engineering Division of the U.S. Army Air Service, McCook Field, Ohio
   Power Plants:
   (D.H.9A)
   One 375 h.p. Rolls-Royce Eagle VIII
   One 400 h.p. Liberty 12
   One 400 h.p. aircooled Liberty 12
   One 450 h.p. Napier Lion
   One 465 h.p. Napier Lion II
   (D.H.9AJ) One 465 h.p. Bristol Jupiter VI
   (USD-9) One 400 h.p. Liberty 12
   (USD-9A) One 400 h.p. Liberty 12
   (USD-9B) One 420 h.p. Liberty 12A
   (H.P.20) One 400 h.p. Liberty 12
   Dimensions:
   Span 45 ft. 11 3/8 in. Length 30 ft. 3 in. (Lion) 29 ft. 2 in.
   Height 11 ft. 4 in. Wing area 486 3/4 sq. ft. (D.H.9AJ) 491 sq. ft.

Weights and Performances:

   D.H.9A Stag

Engine Liberty Eagle VIII Lion Jupiter VI
Tare weight 2,800 lb. 2,705 lb. 2,988 lb. 2.740 lb.
All-up weight 4,645 lb.* 4,223 lb. 4,814 lb. 4,324 lb.
Speed
   at 10,000 ft. 114 1/2 m.p.h. 118 m.p.h. 123 m.p.h. 130m.p.h.
Initial climb 890 ft./min. 850 ft./min. 1,100 ft./min. 900 ft./min
Ceiling 16,750 ft. 16,000 ft. 19,000 ft. 19,900 ft.
Duration 5 1/4 hours 3 1/2 hours - -
* USD-9A 4.900 lb.

F.Manson British Bomber Since 1914 (Putnam)

Airco D.H.9A

   The original plans for the creation of a strategic bombing force in 1917 assumed the use of light day bombers capable, if not necessarily of being fully able to defend themselves, at least of being escorted by fighters, and a force of heavy night bombers. The appearance of the D.H.9, steadfastly favoured by ministers and boards remote from the fighting fronts, attracted bitter criticism from commanders in the field, who pointed to its lack of speed, agility and muscle, as well as its inevitable obsolescence by mid-1918.
   Plans to introduce a new version, the D.H.9A, powered by the 375hp Rolls-Royce Eagle VIII, suffered a major setback when the Air Board allocated elsewhere the great majority of these, the best British engines being produced in quantity during the winter of 1917-18. As a result, attention was quickly focused on the new American Liberty 12 for which extravagant steps had been announced towards mass production, and had first flown in a D.H.4 during October 1917 - and by the end of January 1918 the Air Board had requested the supply of 3,000 examples.
   Because the Aircraft Manufacturing Company was by then fully occupied with developing the D.H. 10, responsibility for redesigning the D.H.9 to incorporate the American engine was vested in the Westland Aircraft Works, a manufacturer that had already built numerous D.H.4s and D.H.9s, and whose high quality of workmanship was something of a byword in aviation circles. New wings of almost 46 feet span, and with an area increased by 12 per cent, were designed, and the fuselage box-girder was strengthened by employing wire cross-bracing in place of the former ply partitions. Because no Liberty engine was yet available, a Westland-built D.H.9 underwent these airframe modifications and was fitted with an Eagle VIII together with a frontal radiator similar to that of the Liberty engine. The structure of the latter engine's installation was similar to that of the Rolls-Royce, and in due course, when production of the Eagle increased, the new D.H.9A with the British engine was also built in small numbers (though the Liberty version came to be regarded as the standard machine). B7664 was first flown at Yeovil in March 1918 and underwent Service evaluation at the EAS the same month; the first Eagle-powered prototype had arrived at Martlesham towards the end of February.
   The first Liberty 12 was received by Westland in March; indeed, production of the American engine began to lag behind schedule from the outset, and delivery of the 3,000 engines for Britain, intended to be completed by the end of July 1918, was suspended in August after no more than 1,050 had been shipped. The first Liberty-powered, British-built D.H.9A, C6122, was flown by Harry Hawker at Yeovil in April, and by the end of June 18 examples had been delivered to the RAF.
   One of the early Liberty-D.H.9As was flown at Martlesham in July, enabling comparisons to be made with the Eagle aircraft. When carrying a pair of 230 lb bombs the normal load - there was little to choose between the two versions, although with the extra power of the Liberty the aircraft with this engine returned a service ceiling of 16,750 feet, compared with 14,000 feet with the Eagle. Endurance was also significantly better. However, the Eagle D.H.9A demonstrated its ability to carry a maximum bomb load of 740 pounds.
   Eight squadrons of the RAF received D.H.9As before the Armistice, of which four were light bomber units that took part in bombing operations, two did not become operational during the War, and two were engaged in anti-submarine patrols flying from Great Yarmouth in Norfolk.
   The First Squadron to take deliveries was No 110 in July 1918, then stationed at Kenley with D.H.9s. The Squadron moved to France where it became part of the Independent Force at Bettoncourt on 1 September. All this unit's initial complement of D.H.9As ('Nine-Acks' in the current RAF parlance) were subscribed by HH the Nizam of Hvderabad, a gesture that gained lasting recognition when the Squadron was officially named No 110 (Hyderabad) Squadron. Unfortunately No 110 fared badly in the small number of operations flown before the Armistice and, in a daylight raid on Frankfurt on 21 October, 7 out of 13 aircraft despatched failed to return, and another returned early with engine trouble. During its two months in action the Squadron lost 17 D.H.9As to enemy action, and 28 others in accidents.
   In August No 205 Squadron began re-equipping on its French aerodrome at Bovelles, followed by Nos 99 in September and 18 in October. Nos 25 and 120 Squadrons, though in the process of re-equipping with D.H.9As at the time of the Armistice, had no opportunity to fly them in action. Two Squadrons at Great Yarmouth, Nos 212 and 273, received their new machines in August and September and flew them on a number of anti-submarine patrols before the end of hostilities.
   By the end of the War a total of 2,250 D H.9As had been ordered from six manufacturers, the vast majority of them scheduled to be powered by Liberty 12s; by 31 December, 885 of these aircraft had been built. However, that month had brought about the cancellation of 520 aircraft, despite the decision taken to retain the D.H.9A in the peacetime RAF; it is likely that the cancellation was brought about owing to the uncertainties surrounding the continued production of the Liberty 12 in America. Any fears of that production being terminated however, proved groundless, and the Americans were quick to recognize the excellence of their engine. On the other hand, with the Geddes Axe beginning to be imposed in Britain, there were other uncertainties concerning the likely size o f the peacetime RAF, and the scale of appropriations likely to be voted in Parliament. (Bearing in mind this uncertainty, it is perhaps worth mentioning that the 375hp Eagle VIII was almost exactly one-third more expensive than the 400hp Liberty engine.)

Postwar Service

   Paradoxically all the above squadrons disposed of their D.H.9As within eighteen months of the Armistice, all but one of them being disbanded; only No 25 Squadron survived, to become a fighter squadron on 1 February 1920, flying Sopwith Snipes.
   Two other squadrons were equipped with D.H.9As for a short time immediately after the War. No 57 Squadron was given a few of the new aircraft with which to operate a temporary mail service between France and the United Kingdom before being disbanded in December 1919.
   No 221 Squadron (formerly 'D' Squadron of the RNAS prior to the creation of the Royal Air Force) had been engaged in bombing duties in the Aegean with D.H.4 sand 9s during 1918. On moving to Mudros in December that year, it was equipped with D.H.9As before embarking in HMS Riviera for southern Russia, setting up a temporary base at Baku on the shores of the Caspian. It then flew north to Petrovsk whence it carried out bombing raids and armed reconnaissance over Astrakhan in support of 'White Russian' forces fighting the Bolsheviks. In September the RAF personnel were ordered home and the D.H.9As were handed over to the Russians. (The D.H.9A was also built in Russia as the R-1, being powered by M-5 engines assumed to be copied from the Liberty.)
   In due course the D.H.9A was confirmed as the RAF's principal light day bomber in the peacetime Service; between 1920 and 1931 it served on no fewer than 24 squadrons, nine of them in the Middle East and India. The early 1920s were the period o f the RAF's fight for survival in the face of wrangling by the War Office and Admiralty, each determined to create its own air arm in place of the fledgling Service. Trenchard, as the first Chief of the Air Staff, saw in the light bomber (and implicitly the D.H.9A) the ideal instrument with which to exercise Britain's Mandate to supervise the restructuring of the Middle East, following the destruction of the Ottoman Empire.
   Handicapped by a lack of established aerodromes throughout the theatre, which covered the vast area later defined as Palestine, Syria, Lebanon, Jordan and Iraq, the RAF was initially obliged to depend on stations in north-east Egypt and those at Baghdad and Basra, later establishing bases at Ramleh, Amman, Hinaidi, Kirkuk and Shaibah. To these were added countless desert landing grounds throughout the area at which aircraft could put down to refuel. During 1920 and 1921 five Squadrons, Nos 8, 30, 47, 55 and 84, all flying D.H.9As, were formed or re-formed at Suez, Helwan and Baghdad, retaining these aircraft almost throughout the 1920s.
   Their duties were officially described as local security' but, as the months passed, it became all too clear that self-preservation in an environment of harsh desert conditions was the concern uppermost in the minds of air- and groundcrews alike. The Liberty engine, not conceived to operate in ambient temperatures often well above 35°C, was provided with a larger tropical radiator in the nose plus an additional radiator under the nose, as well as additional water containers carried beneath the wings, lest the machine was forced down in the desert with an overheating engine. Landings in the desert or at one of the makeshift strips were also hard on the aircraft's wheels and tyres, so it became common practice for the 'Nine-Acts' to carry a spare wheel attached to the fuselage for such emergencies.
   Not surprisingly, occasional bombing attacks were carried out against marauding or dissident tribesmen, and their rifles, though often fired at random, presented a threat to the slow and low-flying D.H.9As, whose Vickers and Lewis machine guns were used as a necessary deterrent. The bombs most frequently dispensed were 112-pounders of which, in a temperature of 38°C, the D.H. could scarcely carry more than one - when added to the impedimenta for survival.
   Yet the D.H.9A performed its duties with admirable reliability, the Liberty engine being considered to be 'as good as any Rolls-Royce', while a single well-placed light bomb invariably served to satisfy the purpose of the Mandate.
   In February 1927 No 8 Squadron moved with its D.H.9As to Aden, where an airstrip was established at Khormaksar, later to become an important RAF Station. A year afterwards the D.H.s were replaced by Fairey IIIFs, but No 8 was to remain at Aden until 1945.
   The other overseas deployment of D.H.9As was in India, the first such aircraft arriving at Ambala with No 99 Squadron from France in June 1919. This squadron was disbanded on 1 April 1920 to become No 27 and, as such, moved to Risalpur near Peshawar in the North-West Frontier Province where it was to be joined by No 60 Squadron in April 1923, also with D.H.9As. This theatre and the Khyber Pass in particular, constantly wracked by the depredations of marauding Afghan tribesmen, was even more demanding than the deserts of the Middle East, and the Liberty's reliability was vital, simply because the mountainous terrain rendered any forced landing out of the question.
   At home, the D.H.9A served on Nos 11, 12, 35, 39, 100, 101 and 207 Squadrons, their principal stations being Bircham Newton in Norfolk, and Spittlegate, Grantham. The last front-line aircraft to serve with the regular Service in the United Kingdom were those of No 35 Squadron, replaced by Fairey IIIFs in January 1930.
   The D.H.9A was notable in one other respect in being selected as the initial equipment of the Auxiliary Air Force, which came into being in September 1925. The first three Squadrons, Nos 600 (City of London), 602 (City of Glasgow) and 603 (City of Edinburgh), received their first aircraft in October that year at Northolt, Renfrew and Turnhouse respectively, all being declared light bomber units. In the years that followed they were to be joined by Nos 601, 604 and 605 Squadrons, and No 501 Squadron of the Special Reserve at Filton.
   Although production of the D.H.9A, ordered under wartime contracts, had been allowed to run out in 1919, with many of the early production aeroplanes undergoing progressive modification and rebuilding in the course of the next seven years, new production contracts were found necessary in 1925 and 1926. To cater for slightly modified requirements, new contracts were issued to de Havilland, Westland, Short, Hawker, Parnall, Saunders and Blackburn - in some instances for work that was to provide a lifeline at a time when the aircraft industry was fighting for survival. Among the new aircraft produced under these contracts was a Westland-built batch of 35 D.H.9A (Dual Control) trainers, J8460-J8494. Another batch of aircraft, converted by Westlands during rebuilding, were six much-modified D.H.9As, J6957-J6962, powered by 465hp Napier Lion II engines - which bestowed a sea level maximum speed of 144 mph; only one o f these Lion aircraft ever served with a Squadron when J6958 joined No 55 in February 1927 at Hinaidi, Iraq, for the personal use of Air Vice-Marshal Sir John Higgins KCB, KBE, DSO, AFC, Air Officer Commanding British Forces in Iraq.

   Type: Single-engine, two-seat, two-bay biplane light bomber.
   Manufacturers: Wartime. The Aircraft Manufacturing Co Ltd, Hendon, London NW9; F W Berwick & Co Ltd, Park Royal, London NW10; Mann, Egerton & Co Ltd, Aylsham Road, Norwich, Norfolk; The Vulcan Motor and Engineering Co (1906) Ltd, Crossen, Lancashire; Westland Aircraft Works, Yeovil, Somerset; Whitehead Aircraft Co Ltd, Richmond, Surrey. Postwar. The de Havilland Aircraft Co Ltd, Stag Lane, Edgware, Middlesex; The Blackburn Aeroplane and Motor Co Ltd, Leeds and Brough, Yorkshire; II G Hawker Engineering Co Ltd, Canbury Park Road, Kingston-upon-Thames, Surrey; George Parnall and Co Ltd, Coliseum Works, Bristol; S E Saunders Ltd, East Cowes, Isle of Wight; Short Bros (Rochester and Bedford) Ltd, Rochester, Kent; Westland Aircraft Works, Yeovil, Somerset.
   Powerplant: One 400hp Liberty 12 twelve-cylinder, water-cooled, in-line engine; 375hp Rolls-Royce Eagle VIII; 465hp Napier Lion II.
   Structure: Wire-braced wooden box structure in fuselage; forward section ply covered, rear fabric-covered. Laminated spruce wing spars.
   Dimensions: Span, 45ft 11 3/8in; length (Liberty 12 engine), 30ft 3in; height, 11ft 4in; wing area, 486.75 sq ft.
   Weights (Liberty 12): Tare, 2,800 lb; all-up (two 230 lb bombs), 4,645 lb.
   Performance (Liberty 12, with two 230lb bombs): Max speed, 123 mph at sea level, 114.5 mph at 10,000ft; climb to 10,000ft, 15 min 45 sec; service ceiling, 16,750ft; endurance, 5 1/4hr.
   Armament: One synchronized 0.303in Vickers machine gun on port side of nose, with Constantinesco CC interrupter gear, and single or twin Lewis machine guns with Scarff ring on rear cockpit. Bomb load of 740 lb carried on underwing and fuselage racks.
   Prototypes: Three (all converted D.H.9s, two with Eagle engines and one with Liberty 12)
   Production: Wartime orders for 2,250 aircraft, of which 1,730 were built, plus peacetime orders for 267 aircraft of which all were built; total production, 1,997. Aircraft built: Wartime production: Whitehead, 300 (E701-E1000); Airco, 575 (E8407-E8806 and H1-H175); Mann, Egerton, 150 (E9657-E9756 and J551-J600); Vulcan, 225 (E9857-E9956 and H3546-H3670); Westland, 350 (F951-F1101, F1603-F1652 and H3396-H3545); Berwick, 140 (F2733-F2872); Peacetime production: de Havilland, 45 (J7700, J7787-J7798, J7877-J7883 and J8129-J8153); Westland, 101 (J7799-J7819, J7855-J7866, J8096-J8128 and J8460-J8494); Short Bros, 37 (J7823-J7834, J7884-J7890 and J8154-J8171); Hawker, 30 (J7835-J7854 and J7867-J7876); Parnall, 18 (J8172-J8199); Saunders, 18 G8190-J8207); Blackburn, 18 (J8208-J8225). In addition, 204 aircraft were rebuilt (usually involving the assembly of stored components), all being allocated new serial numbers, by the following: Westland (66), Handley Page (21), de Havilland (18), Gloster (35), Hawker (39), and Packing Depot, Ascot (25).
   Summary of Service: D.H.9As served with Nos 18,99,110 and 205 Squadrons, RAF, on the Western Front; with No 25 Squadron in Germany, 1919; with the following home-based light bomber Squadrons after the War, Nos 11, 12, 35, 57, 100, 101 and 207 Squadrons; with Nos 212 and 273 Squadrons, home based on coastal patrol duties; with No 3 Squadron, home-based for fleet cooperation; with No 24 (Communications) Squadron; and No 120 Squadron, home-based for mail services. D.H.9As served with the RAF overseas with No 8 (Iraq and Aden), 14 (Palestine), 27, 30, 39 and 60 (India), 45 (Egypt), 47 (Russia and Egypt), 55 and 84 (Iraq), and 221 (Russia). D.H.9As equipped No 501 Squadron of the Special Reserve, and Nos 600, 601, 602, 603, 604 and 605 Squadrons of the Auxiliary Air Force.

P.Lewis British Bomber since 1914 (Putnam)

Current shortage of Eagle engines to meet the demand for such a first-class unit was responsible for the decision to use the American Liberty engine as the power plant in a development of the D.H.9 day bomber, the design of which was undertaken by Westland to become the D.H.9A. Larger wings than those of the D.H.9 were used, and the prototype D.H.9A - B7664 - made its debut with the 375 h.p. Eagle VIII installed, complete with frontal radiator. Eventually the 400 h.p. Liberty 12 arrived on the D.H.9A scene in C6122.
   Despite pressure from the Front, the first D.H.9A squadron - No. 110 - was unable to reach France until 31st August, 1918. Teething troubles with the Liberty were eventually overcome so that the D.H.9A was evolved into a steady and reliable machine for its job. The aircraft’s offensive load consisted of a maximum of 660 lb. of bombs carried beneath the fuselage and lower wings, and its armament comprised a Constantinesco-synchronized Vickers for the pilot and either one or two Lewis guns for the observer.

J.Bruce British Aeroplanes 1914-1918 (Putnam)

de Havilland 9A

  THE story of the designing of the American Liberty engine was launched in a blaze of publicity on August 12th, 1917, when an official statement was issued by the American Secretary of War. This statement described how the first engine was completed only twenty-eight days after the drawings were commenced, unquestionably a fine engineering achievement, and went on to describe the sterling qualities of the new power unit in glowing terms. The description of the first Liberty as “the best aircraft engine produced in any country” was somewhat premature, however, for it had not flown at the date of the Secretary of War’s statement.
  The first Liberty was an eight-cylinder vee engine, designed by Major J. G. Vincent of the Packard company and Major J. G. Hall of the Hall-Scott company, who first met to discuss the design requirements on June 3rd, 1917. The first engine was assembled on July 3rd, 1917, underwent its first bench test on July 23rd, and was flown for the first time on August 20th.
  The construction of a twelve-cylinder version was also put in hand. This engine successfully completed a fifty-hour bench test on August 25th, 1917, and was originally rated at 314 h.p. The output was increased to 395 h.p. by October, in which month the engine was first flown in a D.H.4, and in December, 1917, serious development of the eight-cylinder model was abandoned in favour of the bigger engine.
  Production of the Liberty 12 had already begun, but the original programme was over-ambitious and was never realised: the monthly output which was envisaged was 4,800, which was to be reached by May, 1918. Total deliveries by the end of that month were to reach a figure of 9,420, but in fact only 1,100 Liberty engines had been produced by that date. Production was delayed by lack of jigs, tools and gauges, and the supposedly perfect engine was the subject of no fewer than 1,022 modifications between September, 1917, and February, 1918.
  Nevertheless, the production of 1,100 engines in twelve months from the commencement of design was a considerable achievement.
  The high power output of the engine made it an attractive proposition, and it appealed particularly to Britain as an alternative to the Rolls-Royce Eagle, production of which was falling short of demand. The Allied governments asked for large numbers of Liberties, and by the end of January, 1918, Britain had asked for a total of 3,000. Delivery was to begin that month, and was to be at the rate of 500 per month; but the first ten did not arrive until March, 1918. Deliveries ceased in July, by which time only 1,050 engines were delivered.
  In the expectation of plentiful supplies of Liberty engines, it was decided that the new engine should be used to power a day-bomber type based on the D.H.9 design. At that time, however, the Aircraft Manufacturing Co. were fully occupied with the design of the D.H.10 and were unable to devote any time or personnel to the designing of the new Liberty-powered machine. Responsibility for the modification of the basic D.H.9 design was therefore entrusted to the Westland Aircraft Works, who had been contractors for the manufacture of D.H.4s and D.H.9s.
  The re-designing produced an aeroplane which bore a superficial resemblance to the D.H.4, for the radiator was mounted immediately behind the airscrew. New wings of increased span and chord were fitted, and the fuselage box-girder structure was fully cross-braced by wires, whereas the fuselage of the D.H.9 had embodied a number of plywood cross partitions in place of wires. The plywood covering on the forward portion of the fuselage was retained, and there was a clear-view cut-out in the root of the starboard lower wing.
  The first D.H.9A - for such was the designation of the modified aircraft - was a converted D.H.9, B.7664, which appeared with a 375 h.p. Rolls-Royce Eagle VIII engine, presumably because no Liberty was immediately available. The installation of the Eagle was almost identical to that used for the Liberty, but could be distinguished by the longer exhaust pipes and four-bladed left-hand airscrew. Other D.H.9As had the Rolls-Royce Eagle engine, but the great majority had the Liberty. The first Liberty-powered D.H.9A was C.6122.
  Contracts for production of the D.H.9A were let in March, 1918, and by the end of June eighteen machines had been delivered. During that month Major-General H. M. Trenchard had written from France to say that it was imperative to make every effort to replace the D.H.9s with D.H.9As, but the first squadron to be equipped with the new machine did not arrive in France until August 31st, 1918.
  This unit was No. 110 Squadron, and all its D.H.9As were presented to the R.A.F. by His Serene Highness the Nizam of Hyderabad. Each aircraft bore an inscription to that effect, and the unit became known as the Hyderabad Squadron. On its arrival in France, No. 110 Squadron joined the Independent Force, and carried out its first bombing raid on September 14th, 1918: the objective was the enemy aerodrome at Boulay. The part played by the D.H.9A in the Independent Force’s programme of strategic bombing of industrial targets was not large: in fact, No. 110 Squadron made only five such sorties before the Armistice.
  The squadron’s last strategic attack was made on Frankfurt on October 21st, 1918, and can only be regarded as a fiasco. Thirteen D.H.9As set out from Bettoncourt: one returned with engine trouble, and the formation was broken up by dense clouds; seven failed to return. By that time, of course, the tempo of aerial fighting had quickened enormously, and during its two operational months No. 110 Squadron lost seventeen D.H.gAs by enemy action; a further twenty-eight were wrecked.
  The Liberty engine was not at first successful; indeed, in view of the melodramatic story of its creation, it was looked upon with a certain amount of derision. Much of the trouble was caused by the engine’s coil ignition, to which R.A.F. pilots did not take kindly; but once the engine was properly understood it ran extremely well. It certainly gave the D.H.9A a much better performance than the D.H.9, and remained the standard power unit of the type throughout its long post-war service.
  No. 205 Squadron began to replace their D.H.4s with D.H.9As at the end of August, 1918, and reequipment was complete by the end of the following month. This unit did much good work on the Fourth Army front during the final advance of the Allies. The good performance of the D.H.9A enabled the squadron to fly unescorted, whereas the D.H.9 squadrons had to be escorted to the limits of the range of the fighters.
  The only other units to receive the D.H.9A before the Armistice were Squadrons Nos. 18 and 99; in both cases re-equipment was proceeding in November, 1918. Coastal units began to receive D.H.9As for oversea patrol during the late summer of 1918, but they were not used for that purpose because the original valve gear of the Liberty was not considered safe for over-water flying. The type arrived too late to see action in any other theatre of war, but after the Armistice some went to Russia with Squadrons Nos. 47 and 221, where they shared the rigours of a sub-Arctic winter with D.H.9s.
  The D.H.9A was built, doubtless without licence, in post-Revolutionary Russia. Its Russian designation was R-1, the R signifying “Razv’edchik”, or reconnaissance aircraft. The first Russian-built machines are believed to have had Liberty engines, but later examples were powered by the M-5 engine, which was a copy of the Liberty.
  The fact that the D.H.9A was powered by the Liberty engine naturally commended it strongly to the United States Air Service, and arrangements were made for its manufacture in America. Probably for reasons of prestige, the American version was designated USD-9A. The Dayton-Wright concern built four in October, 1918, and these were followed next month by five constructed by the Engineering Division of the Bureau of Aircraft Production. A contract for 4,000 was given to the Curtiss Aeroplane Co., but was cancelled at the Armistice. Production USD-9As were to have a rudder of slightly more rounded outline than that of the D.H.9A, and the pilot’s Browning gun was mounted on the starboard side. In February, 1919, the Engineering Division fitted wings of increased area to one of their USD-9As and installed a 420 h.p. Liberty 12A engine: this machine was re-designated USD-9B.
  After the war, the D.H.9A remained in service with the R.A.F. for many years at home and overseas. In company with the equally long-lived Bristol Fighter, it undertook the policing of Iraq and the control of refractory tribesmen on the North-West Frontier of India. In its post-war days, the D.H.9A became a general purpose type, and carried a remarkable variety of equipment which included a spare wheel and, when occasion demanded it, water contained in animal skins attached to the gun-ring outside the fuselage. The type ended its career with the Auxiliary squadrons.
  Several D.H.9As were fitted with the Napier Lion engine in the post-war years: the first installation was made in 1919. Oleo undercarriages were also fitted, and J.6957 combined the Lion engine with an oleo undercarriage somewhat reminiscent of that used on Fairey landplanes.
  A further development was the D.H. Stag, which first flew on June 15th, 1926. This was a D.H.9A fitted with a 465 h.p. Bristol Jupiter radial engine; stagger was reduced and a simplified oleo undercarriage was installed.


SPECIFICATION
  Manufacturers: The Aircraft Manufacturing Co., Ltd., Hendon, London, N.W.
  Other Contractors: F. W. Berwick & Co., Ltd., Park Royal, London, N.W. 10; Mann, Egerton & Co., Ltd., Aircraft Works, Norwich; The Vulcan Motor and Engineering Co. (1906), Ltd., Crossens, Southport; Westland Aircraft Works, Yeovil, Somerset.
  Power: 375 h.p. Rolls-Royce Eagle VIII; 400 h.p. Liberty 12; 450 h.p. Napier Lion; 400 h.p. M-5 (Russian copy of Liberty for Russian-built D.H.9As).
  Dimensions: Span: 45 ft 11 3/8 in. Length: 30 ft 3 in. Height: 11 ft 4 in. Chord: 5 ft 9 in. Gap: 5 ft 6 in. Stagger: 1 ft 4 in. Dihedral: 3°. Incidence: 3°. Span of tail: 13 ft 10 in. Wheel track: 6 ft. Airscrew diameter: 10 ft.
  Areas: Wings: upper 249-03 sq ft, lower 237-7 sq ft, total 486-73 sq ft. Ailerons: each 18-59 sq ft, total 74-36 sq ft.
Tailplane: 38 sq ft. Elevators: 24 sq ft. Fin: 5-4 sq ft. Rudder: 13-7 sq ft.

Serial Numbers:
Serial Nos. Contractor
B.7664 (converted D.H.9, Eagle engine) Westland Aircraft
C.6122 (Liberty) Westland Aircraft
C.6350 (Eagle) Aircraft Manufacturing Co.
E.701-E.1000
E.8407-E.8806 Aircraft Manufacturing Co.
E.9657-E.9756 Mann, Egerton & Co.
E.9857-E.9956 Vulcan Motor & Engineering Co.
F.951-F.1100 Westland Aircraft
F.1603-F.1652 Westland Aircraft

  Other Known Serial Numbers: F.2816-F.2869, F.3842, F.9922; H.1-H.150 (at least); between and about H.3430 and H.3650 (H.3486 was built by Westland); H.4243: Westland-built. H.4275. Between and about J.554 and J.568; J.6957-J.6959; J.7008, J.7009, J.7024, J.7030, J.7034, J.7035, J.7038, J.7039, J.7041. J.7047. J.7048, J.7058, J. 7059, J.7062-J.7083, J.7085, J.7086, J.7089, J.7094, J.7107, J.7109, J.7116, J.7117, J.7122, J.7124, J.7302, J.7309, J.7316, J.7329, J.7331-J.7333, J.7337, J.7340, J.7342, J.7356, J.7605, J.7607, J.7614, J.7615, J.7787-J.7798, J.7809, J.7814, J.7818, J.7831, J.7832, J.7835, J.7842, J.7850, J.7854, J.7877-J.7883, J.7888, J.7890, J.8098-J.8223; J.8462, J.8470, J.8472, J.8473, J.8478, J.8489, J.8492.

Weights (lb) and Performance:
Engine Rolls-Royce Eagle VIII Rolls-Royce Eagle VIII Rolls-Royce Eagle VIII Liberty Liberty Lion
Bomb load Nil Two 230-lb Two 230-lb, 14 20-lb Nil Two 230-lb -
No. of Trial Report M.182 M.182 M.182 M.213 M.213 -
Date of Trial Report March, 1918 March, 1918 March, 1918 July, 1918 July, 1918 -
Type of airscrew used on trial D.G.2160 D.G.2160 D.G.2160 X.3012M X.3012M -
Weight empty 2,705 2,705 2,705 2,770 2,800 2,557
Military load 185 608 1,200 185 580 -
Crew 360 360 360 360 360 -
Fuel and oil 550 550 550 905 905 -
Weight loaded 3,800 4,223 4,815 4,220 4,645 4,660
Maximum speed (m.p.h.) at
ground level - - - - 123 -
10,000 ft 125-5 118 1105 120 114-5 134
15,000 ft 116 104-5 - 114 106 125-5
16,500 ft - - - - 102 -
m. s. m. s. m. s. m. s. m. s. m. s.
Climb to
2,000 ft - - - - - - 1 50 2 20 - -
5,000 ft - - - - - - 5 00 6 25 - -
6,500 ft 7 00 8 40 11 00 6 50 8 55 - -
10,000 ft 12 10 15 35 20 35 11 50 15 45 10 30
15,000 ft 22 55 33 40 - - 22 50 33 00 - -
16,500 ft - - - - - - - - 43 50 - -
Ceiling (feet): Service 20,000 16,000 14,000 19,000 16,750 21,300
Absolute 22,000 - - 21,000 18,000 -
Endurance (hours) 4 1/2 - 3 1/2 5 3/4 5 1/4 -

  Tankage: Petrol: 107 gallons, carried in two 50-gallon tanks mounted between the engine and the pilot’s cockpit, and in a 7-gallon gravity tank in the centre-section. Oil: 15 gallons in tank in front of petrol tank. Water: 10 1/2 gallons.
  Armament: One fixed forward-firing Vickers machine-gun mounted on the port upper longeron just in front of the pilot’s cockpit, synchronised by Constantinesco C.C. Gear type B. The observer had either a single Lewis gun or a double-yoked pair on a Scarff ring-mounting on the rear cockpit. The normal bomb load consisted of two 230-lb bombs, but up to 660 lb of bombs could be carried: bombs were carried on racks under the fuselage and lower wings.
  Service Use: Western Front: R.A.F. Squadrons Nos. 18, 99, no and 205. Russia: R.A.F. Squadrons Nos. 47 and 221. Coastal Units: R.A.F. Squadrons Nos. 212 and 273. Training: used at various training aerodromes, including Cranwell, Fowlmere, Waddington.
  Production and Allocation: By the end of December, 1918, a total of 885 D.H.9As had been built. By October 31st, 1918, 272 had been delivered to the R.A.F.: seventy went to the Expeditionary Force, eighty-nine to the Independent Force, and 113 to training units. There were 405 D.H.9As on charge of the R.A.F. on October 31st, of which sixty-six were with the Expeditionary Force, eighty-three with the Independent Force, twelve at coastal aerodromes, fifty at training units, 105 with contractors, twenty-five with squadrons mobilising, two at Aeroplane Repair Depots, twenty-four in store, and thirty-eight were at sundry stations.
  Costs:
   Airframe without engine, instruments and guns £1,599 12s.
   Engines:
   Liberty 12 £1,215 0s.
   Eagle VIII £1,622 10s.

O.Thetford Aircraft of the Royal Air Force since 1918 (Putnam)

de Havilland D.H.9A

   One of the most famous of RAF aircraft, the DH 9A rivalled the Bristol Fighter and Avro 504 for longevity. Known familiarly as the ‘Ninak’, the DH 9A was introduced during the last six months of the First World War and remained in service until as late as 1931. In 1921 an inventory of RAF aircraft showed that 271 DH 9As were in squadron service, 124 at training schools and a further 268 in storage.
   Developed as a replacement for the DH 9 with the Independent Force, the DH 9A had increased wing area and was powered by the 360hp Rolls-Royce Eagle or 400hp Liberty engine, the prototypes being B7664 and C6122 respectively.
   The DH 9A first entered service with No 110 Squadron in June 1918, but did not reach France until 31 August. Operating in close formation at 17,000ft, the DH 9As were extremely effective in daylight raids on German towns, and by the Armistice No 110 Squadron had dropped ten and a half tons of bombs with relatively light losses. Other DH 9A squadrons on the Western Front were Nos 18, 99 and 205. Nos 47 and 221 Squadrons were also equipped in Russia during 1919-20 while fighting the Bolsheviks.
   The DH 9A’s parent company for production was Westland at Yeovil, the company that later produced the Wapiti as the Ninak’s replacement. By 1919 1,780 DH 9As had been built on wartime contracts, and during the 1920s further contracts called for 435, embracing both refurbished aircraft taken out of storage and some newly built.
   Rebuilt DH 9As, delivered to the post-war RAF between 1923 and 1925 were given serial numbers between J6957 and J7356; they had been renumbered from their wartime identities, but others continued with their original numbers in the ‘E’ and ‘F’ series. Between 1925 and 1927, sixteen additional contracts were raised with Blackburn, de Havilland, Gloster, Handley Page, Hawker, Parnall, Saunders, Short Bros and Westland for DH 9As between J7787 and J8494, the last DH 9A to be manufactured. It was first flown on 17 May 1927 and was delivered to No 1 FTS at Netheravon.
   The DH 9A was standard equipment with home-based day bomber squadrons until the arrival of the Fairey Fawn, and was one of the mainstays of squadrons overseas until replaced by the Wapiti and Fairey IIIF. It also served with the Auxiliary Air Force from its inception in 1925, and with Flying Training Schools. Wing Drill by Nos 39 and 100 Squadrons was a feature of the 1924 Hendon Display, and in 1927 Nos 600 and 601 Squadrons represented the Auxiliaries for the first time.

TECHNICAL DATA (D.H. 9A)

   Description: Two-seat day bomber. Wooden structure, fabric covered.
   Manufacturers: Westland Aircraft Works, Yeovil, Somerset. Widely sub-contracted.
   Powerplant: One 400hp Liberty 12A.
   Dimensions: Span, 46ft; length, 30ft; height, 10ft 9in; wing area, 488sq ft.
   Weights: Empty, 2,695lb; loaded, 4,645lb.
   Performance: Max speed, 114mph at 10,000ft; initial climb, 890ft/min; endurance, 5 3/4hr; service ceiling, 16,750ft.
   Armament: One Vickers gun forward, and one Lewis gun aft; bomb load, 450lb.
   Squadron Allocations (post-war). Home: Nos 11 (Andover), 12 (Northolt), 15 (Martlesham Heath), 35 (Bircham Newton), 39 (Spittlegate and Bircham Newton), 100 (Spittlegate), 101 (Bircham Newton)), 207 (Bircham Newton and Eastchurch), 501 (Filton), 600 and 601 (Northolt and Hendon), 602 (Renfrew), 603 (Turnhouse), 604 (Hendon) and 605 (Castle Bromwich). Overseas: No 8 (Iraq and Aden), 14 (Palestine), 27 (India), 30 (Iraq), 45 and 47 (Egypt), 55 (Iraq), 60 (India) and 84 (Iraq). Russia (1919-20): No 47 (one Flight) and 221. Mail: Nos 57 and 120. Coastal: Nos 3, 212 and 273.

H.King Armament of British Aircraft (Putnam)

D.H.9A. The fine distinction in RAF nomenclature between the terms 'day bomber', 'light bomber' and 'single-engined bomber' and the generic classification 'general purpose aircraft' is to be seen most clearly in the evolution and employment of this archetype of all 'G.P.' machines - which began its career in 1918 as a strategic bomber. Of such importance and enduring memory was the 9A in RAF service that its lineage and 'general purpose' development may now be established upon the authority of a document promulgated by the Air Ministry (Directorate of Research) in April 1922. This contained the following significant passage - possibly the original instance of the term 'general purpose' appearing in a Service publication. Thus:
   'Though officially classed as a two-seater fighter reconnaissance type [sic] the functions of this aircraft cover, in practice, a wider field and it could aptly be described as a general purpose two-seater. For long-distance reconnaissance, photographic work, day or night bombing or artillery observation, it is equally useful, and its high speed and strong armament render it a particularly formidable opponent."
   Armament is thereafter summarised as:
   'Pilot. 1 Vickers gun and 750 rounds; observer, 2 Lewis guns and six drums; bombs (under fuselage), 4-20 lb, or 2-112 lb, or 1-230 lb; bombs (under each plane), 4-20 lb, or 1-112 lb.'
   In a subsequent passage no mention is made of the twin Lewis installation, but there is a reference to a performance test with two 230-lb bombs. The main account runs:
   'The D.H.9A normally carries two guns, one fixed Vickers machine gun on the port side of the fuselage and a Mk.III Lewis gun mounted on a standard Scarff ring No.2, over the observer's cockpit. Bomb gear and a bomb sight, as well as wing-tip flare brackets, are also fitted.'
   This information is expanded as follows:
   'The Vickers gun was originally arranged parallel to the upper longerons. This position was found to be unsatisfactory, however, as, owing to the pilot's cockpit being so far back, it was impossible for the pilot to get an uninterrupted line of sight. In consequence the gun is now mounted at an angle of 3 1/2 degrees in relation to the top rail of the fuselage. The gun is bolted to two mild steel U brackets of 10 S.W.G., one front and one rear.
   'The gun is synchronised with the propeller in the normal way by means of Constantinesco gear, and is fired by means of a Bowden lever and cable fitted on the control lever. At the rear of the engine, concentric with the crankshaft, a cam box with a splined shaft is fitted to engage with the hollow end of the crankshaft. A Type B synchronising gear with Type C trigger motor is fitted, but an adapter is supplied so that Type B lines may be used. The loading handle fitted to the gun is of the Cox D type.
   'The magazine is constructed of sheet aluminium and takes a belt of 750 rounds. It is supported on sheet steel brackets, and the belt passes over a 3 in roller into the gun. The spent cartridges are ejected through a chute and fall clear of the aircraft. An Aldis sight is mounted on the starboard side of the fuselage cowling. In the corresponding position on the port side is fixed a standard ring-and-bead sight.
   'The observer's cockpit is furnished with the standard Scarff gun ring, carrying a Lewis Mk.III gun fitted with a Norman vane 100 m.p.h. sight. Four pegs are provided for carrying the necessary ammunition drums and are accommodated in a special uncovered compartment immediately behind the cockpit. Both the Vickers and Lewis guns are fitted with the standard electric gun heater.'
   Of the bomb installations:
   'Two similar 18 S.W.G. mild steel ribs, each of flanged U section, are bolted lo four bottom fuselage struts, so that approximately one-third of each rib lies behind the rear spar. The ribs are parallel to the longitudinal axis of the aircraft and are 21-in apart. A similar pair of steel ribs, again 21-in apart, are fitted underneath each wing. Bomb gear comprises the standard bomb releasing toggles, working through stranded cable. The schedule provides for the fitting of one high-altitude drift sight and one negative lens bomb sight.'
   It is pertinent lo include the following note on electrical equipment:
   'The D.H.9As in service at the time of writing do not carry the full standard electrical equipment. Many are either not furnished electrically or only partially equipped, while others have a war-time equipment.'
   On post-war aircraft of this type, arrangements were made for eight, instead of four 20-lb bombs to be carried under each wing (two tandem carriers). The Vickers gun was often of the Mk.II pattern with small perforated barrel casing and a G.3 camera gun was sometimes mounted on the port lower wing. A prone bomb-aimer's position was incorporated, as indicated by two windows in the fuselage sides near the bottom longerons.
   Already the 9A was being made to carry (in the phrase which this aeroplane brought into Service currency) everything except the kitchen sink, and when geographical and climatic demands were superimposed, it became less of a war-horse and more of a beast of burden. Apart from an auxiliary radiator, oleo undercarriage (occasional), cameras, camera gun, etc. the following inventory was listed by (the writer believes) Sir Arthur Longmore: auxiliary tank, giving an endurance of seven hours; spare tyre strapped under fuselage (camel-thorn punctures); emergency rations for three days; two gallons of water; special container for beer bottles; and a gadget to work the rudder bar by hand so that the pilot could stretch.
   In connection with the Handley Page O/400, mention will be made of a bomb-aiming technique involving the tying of string to the pilot's ankles, and a similar technique is known to have been employed with the D.H.9A.
   Finally it may be noted that in 1921 an Air Ministry Order made allusion to modifications concerning the R.L. Launching Tube on aircraft of this type. This device had been developed by the Royal Laboratory early in the 1914-18 war with the intention of launching incendiary bombs against airships, though it was also associated with flares and markers.


D.H.9b. This designation was applied to a post-war development of the 9A, remodelled by the Aircraft Disposal Company, having an Eagle VIII engine with Lamblin radiators and augmented armament. Provision was made for three 230-lb bombs, two fixed Vickers guns, two Lewis guns on a Scarff ring-mounting and a third Lewis gun firing through the floor, for which a sliding hatch was provided.


D.H.9AJ Stag. This Jupiter-engined general purpose development of the D.H.9A appeared in 1926 and was beaten in competition by the Wapiti. War load was typically four 112-lb or two 230 250-lb bombs. Vickers gun (external port), and Scarff ring-mounting with Lewis gun. There was a prone bombing position, with wind deflector.

K.Wixey Parnall Aircraft Since 1914 (Putnam)

De Havilland D.H.9A Contracts

   Throughout aviation history there have been aircraft which could be singled out as outstanding for their time. In the Royal Air Force one such aeroplane, noted for its longevity and reliable service both at home and abroad, was the de Havilland D.H.9A. It was this type that provided Parnall with much needed work in the mid-1920s for, although the company was at that time engaged with several prototype projects, the D.H.9A construction contracts awarded by the Air Ministry produced the means by which Yate works could continue to function on a more secure footing.
   The D.H.9A was derived from the D.H.9, a First World War two-seat bomber that was a disappointment because of its Siddeley Puma engine. A converted D.H.9 was fitted with a 375 hp Rolls-Royce Eagle VIII, but the eventual standard powerplant installed was the American 400 hp Liberty 12, an engine produced after the United States entered the war.
   A two-seat, twin-bay conventional biplane, the D.H.9A was of mainly wooden construction and fabric-covered. Although based on the D.H.9 design, the D.H.9A possessed wings of greater chord and span, incorporated wire bracing for the fuselage structure instead of plywood bulkheads, and had a frontal radiator. The type lent itself admirably to the aircraft manufacturing techniques of woodworking companies such as George Parnall.
   In addition to those D.H.9As kept in store after the war, some new machines were built having had modifications introduced. As a consequence several Air Ministry contracts were issued to various manufacturers including Parnall, whose first order was for a batch of eighteen D.H.9A rebuilds (J8172-J8189).
   These aircraft were from a batch of 130 D.H.9As (J8096-J8225) produced after the First World War, the contracts being distributed by the Air Ministry between Westland Aircraft, de Havilland Aircraft, Short Brothers, S.E. Saunders, Blackburn Aircraft and George Parnall.
   In January 1927, an order for a further thirty-five D.H.9As was placed by the Air Ministry, one contract for twenty-three machines (J8460-J8482) going to Westland Aircraft Co. Ltd., while the remaining twelve aircraft (J8483-J8494) were contracted to Parnall at Yate, all these machines being the dual-control training version.
   Familiarly known as the 'Nine-Ack' ('Ninak' for short), the D.H.9A became one of the most widely used aircraft in RAF service during the 1920s. It operated both as a bomber and general purpose type, and served with at least twelve home-based and nine overseas squadrons, the latter based mostly in the Middle East. The D.H.9A shared with the Bristol F.2B the difficult job of policing Iraq and the North West Frontier of India for a number of years. Those 'Ninaks' abroad were fitted with a tropical radiator beneath the nose, and normally carried a spare wheel on the side of the fuselage.
   A distinctive D.H.9A built by Parnall was J8177, which was the personal aircraft of the AOC in Iraq around 1929, Sir Robert Brooke Popham and was finished in an all-over deep red. D.H.9As saw service with the Auxiliary Air Force, and as trainers at RAF Flying Training Schools, the type not being finally withdrawn until 1931.
   Some reflections on the test flying of certain D.H.9As from Parnall's second batch (J8483-J8494) can be found in these notes from Frank Courtney's log, when he was contracted as test pilot to the Yate works.
   14.3.27 Two flights in D.H.9As which were from batch by George Parnall & Co at Yate. These machines were J8484 (30 minute recondition test flight) and J8483 (40 minute recondition test flights, three in all).
   21.3.27 Parnall-built de Havilland 9A J8485. 40 minute production test flight. A second Parnall D.H.9A, J8486, taken on 30 minute production test flight from Yate also on the same day.
   29.3.27 Parnall-built D.H.9A, J8487. 10 minute production test flight from Yate.
   5.4.27 Parnall-built de Havilland 9A, J8489. 30 minute production test flight from Yate.
   30.4.27 Parnall-built de Havilland 9A, J8490. 30 minute production test flight from Yate. Second production test flight followed with D.H.9A, J8491, and a third similar test flight with Parnall-built D.H.9A, J8492, of 30 minutes' duration concluded work at Yate for this particular day.
   17.5.27 Parnall-built de Havilland 9A, J8493. 30 minute production test flight from Yate. Second D.H.9A, J8494, taken up later same day on 35 minute production test flight also at Yate.

De Havilland D.H.9A (as built by Parnall)
   Two-seat general purpose and training biplane. 400 hp Liberty 12 twelve-cylinder vee water-cooled engine.
   Span 45 ft 11 1/2in; length 30 ft 3 in; height 11ft 4 in; wing area 488 sq ft.
   Empty weight 2,695 lb; loaded weight 4,645 lb.
   Maximum speed 114 mph at 10,000 ft; climb to 10,000 ft, 15 min 45 sec; service ceiling 16,750 ft; endurance 5 1/4 hr.
   One fixed forward-firing .303-in Vickers machine-gun and one Scarff-mounted .303-in Lewis machine gun. Bomb load 660lb (normally two 230lb or four 112lb bombs).

Production (Parnall only)
   First contract 18, second contract 12.

G.Swanborough, P.Bowers United States Military Aircraft Since 1909 (Putnam)

ENGINEERING DIVISION USD-9

   The USD-9 was an American redesign of the British DH-9 in the same manner that the “Liberty Plane” was an Americanization of the original DH-4. Principal outward difference between the -4 and -9 was the relocation of the pilot’s cockpit, which was moved aft while the fuel tank, originally between the cockpits, was moved forward. All USD-9s as well as 9As used the Liberty. The Armistice ended production after nine had been built at McCook Field (40060/40068) and four by Dayton Wright (40044, 40118, 40119 plus one).
   Span, 46 ft.; length, 30 ft. 2 7/8 in.; wing area, 508 sq. ft.; empty weight, 2,815 lb.; gross weight, 4,322 lb.; high speed, 126 m.p.h.

G.Swanborough, P.Bowers United States Navy Aircraft Since 1911 (Putnam)

DE HAVILLAND D.H.9A

Among the British aircraft supplied to the US Navy for use by the Northern Bombing Group in France in 1918 were 54 D.H.9A two-seat bombers powered by 400 hp American Liberty engines. These were not assigned regular US Navy serial numbers, but flew with American roundels being painted over the British on the wings, and the fuselage roundel being painted out and replaced by station markings. Span, 42 ft 5 in; length, 30 ft; gross weight, 4,645 lb; max speed, 114 mph at 10,000 ft.

L.Andersson Soviet Aircraft and Aviation 1917-1941 (Putnam)

De Havilland D.H. 4, D.H.9, R-1 and variants

   Lacking resources for development of advanced and specialized aircraft the fledgling Soviet aviation industry copied what was at hand when production started again after the Civil War, a proven, reliable, versatile aircraft of simple construction - the de Havilland D.H.9 which later became known as the R-1 in the Soviet Union. Being used for reconnaissance, artillery observation, light bombing, attack, civil and military training, maritime patrol, seaplane training, liaison, target-towing, mail-carrying, experiments and in other roles, the R-1 was the Soviet aircraft of the 1920s. Nine different types of engines were installed in de Havilland and R-1 aircraft; Liberty, Siddeley Puma, Fiat, Rolls-Royce Eagle, Mercedes, M-5, Maybach, BMW and Lorraine-Dietrich, but the M-5-powered R-1s were the most numerous.

   The D.H.9 was structurally similar to its predecessor and used identical wings and tail section, but the pilot's cockpit was moved back behind the fuel tanks and the forward part of the fuselage was better streamlined. A retractable radiator was fitted under the front fuselage. A D.H.4 was converted to the new standard and tested in July 1917, whereupon production immediately switched to the new model. Most of the D.H.9s were powered by the 230hp Siddeley Puma, but with this engine the new model was under-powered and, in fact, inferior in performance to the D.H.4 which it was to supplement rather than replace. The D.H.9A appeared in 1918. Developed by the Westland Aircraft company, it combined the 400hp Liberty engine and frontal radiator with the best features of the D.H.4 and D.H.9. The fuselage was strengthened by replacing the plywood partitions of the D.H.9 with wire cross bracing and wings of greater span were fitted to improve climb and ceiling.
   After the war surplus D.H.9 and D.H.9A aircraft were reconditioned and exported, many by the Aircraft Disposal Company, or used for civil purposes and in the 1920s D.H.4, D.H.9 and D.H.9A aircraft served with the military air services of Arabia, Argentina (one only), Australia, Bolivia, Belgium, Canada, Cuba, Chile, Mexico, Estonia, Greece, Ireland, Latvia, Holland, New Zealand, Nicaragua, Poland, Romania, Switzerland, Spain, South Africa, Turkey, the USA and the USSR.

   By the end of 1920 nineteen captured Puma-engined D.H.9s and Liberty-engined D.H.9As were on charge. They were used mostly in the Ukraine and in Caucasia. More were repaired and put into service during the following year and by December 1921 forty-three were flying with RKKVF units. The authorities in Moscow had noted the reliability of the de Havilland types and when the opportunity arose to purchase more such aircraft from Britain there was no hesitation. The Secretary of the Royal Swedish Aero Club, Torsten Gullberg, who had been discussing an airline project with the Soviet Government offered to supply aircraft to the USSR in the spring of 1921. He contacted the Aircraft Disposal Company and began negotiations concerning reconditioned D.H.9s without engines. In Sweden he acquired 260hp Mercedes engines which had been smuggled out from Germany after the war and stored. A contract for forty aircraft and forty-eight engines was signed on 22 December 1921.
   E I Gvaita went to England for inspection and acceptance of the aircraft. Four of the engines were sent to England and installed in each of the aircraft, which were then shipped from London to Leningrad on board the Swedish freighter Miranda. They arrived on 4 June 1922. The engines were shipped separately from Sweden. Anton Nilsson, another Swede who had joined the RKKVF as a pilot, was sent to Leningrad to supervise unloading of the consignments. These D.H.9s had the following s/ns: 1243, 1285, 2803, 5580, 5582, 5671, 5703, 5713, 5720, 5729, 5744-5746, 5748, 5752, 5758, 5778, 5786, 5795, 5800, 5803, 5805, 5808, 5811-5813, 5815, 5817, 5819, 5821, 5826-5828, 5832, 5841, 5846, 9152, 9165, 9334 and 9350 (most were almost certainly from the D and H serial batches). The first aircraft assembled by RVZ No. 1 and tested by Savin on 14 August was s/n 5817. Two aircraft (s/ns 5778 and 5813) were kept at the NOA.
   One D.H.9A fitted with the 320hp Rolls-Royce Eagle VIII engine was delivered in May 1922 for evaluation and in 1923 ten D.H.9As with 400hp Liberty and twenty D.H.9s with 220hp Puma engines were acquired from England via the Arcos Company. The Saturn arrived at Leningrad from London via Antwerp and Reval with seventeen of these aircraft in October 1923. Another four D.H.9As (Liberty engine) and twenty-two D.H.9s (Puma engine) followed in August 1924. In VVS documents the Rolls-Royce powered aircraft is identified as number 16105, but A J Jackson's De Havilland Aircraft since 1909 (Putnam, third edition, 1987) gives this aircraft as c/n 37. The ten D.H.9As were s/ ns 157 to 160, 2866, 2870, 3457, 3647, 3649, and 8802. The twenty D.H.9s were s/ns 138, 168, 206 to 213, 255, 468, 636, 1209, 5541, 5814, 9277, 9290, 9294 and 9329. The twenty-two D.H.9s delivered in 1924 were probably H5855, H5864, H5880, H9242, H9250, H9252, H9260, H9275, H9278, H9283, H9285, H9297, H9298, H9302, H9309, II9311, H9313, H9330, H9341 and H9309 which received British Cs of A in July 1924, and two others.
   The British-built D.H.9s were used by the 1st Otdel'naya razvedivatel'naya aviaeskadril'ya at Ukhtomskaya, Moscow, the 2nd Otdel'naya razvedivatel'naya aviaeskadril'ya at Vitebsk and the 5th Otdel'nyi razvedivatel'nyi aviaotryad at Gomel' until 1924. One or two served with the 3rd, 6th, 10th, 13th and 14th Otdel'nye razvedivatel'nye aviaotryady in 1922-24, and later with the 17th and 83rd Aviaotryady and the 20th and 24th Aviaeskadrilii. The 4th Otdel'nyi razvedivatel'nyi aviaotryad at Tashkent received about ten in 1924 and used them into 1925, but four of these were flown to Kabul in October and handed over to the Afghanistan Government.
   The Il'ich otryad, named after Lenin, whose middle name was Il'ich, was formed in April 1924 at Khar'kov. Twelve D.H.9As arrived in December 1923 and were assembled locally. Nine of these aircraft were handed over with ceremony by the ODVF on 18 May, 1924 and were followed by another four in June and July. They were given names including Donetskii shakhter, Krasnyi Kievlyanin, (Jkrainskii chekist, Shakhter Donhassa, Stalinskii proletarii, Profsoyuzy Ekaterinoslavshchiny, Samolet Sumshchiny, Yuzovskii proletarii, Chervonii vartovik podolii, Nezamoshnik Odesshchiny and Proletarii Odesshchiny (Donets Miner, Red Kiev Inhabitant, Ukrainian Cheka Officer, Miner of the Donbass, Stalin Proletarian, Trade-Unions of the Ekaterinoslav Region, Aircraft of the Sumy Area, Yuzovka Proletarian, Red Guard of Podol'e, Odessa Pauper, Odessa Pro-letarian). The D.H.9As of this unit were replaced, however, by Soviet- built R-ls before the end of the year.
   The Mercedes-powered D.H.9s were withdrawn from use completely in 1925 and nineteen were handed over to Dobrolet along with forty-seven engines in 1927. Ten, and later one more, were assembled and the rest were reduced to spares. The Dobrolet D.H.9s did not receive normal civil registrations and had large white numbers painted on the fuselage sides instead, which were treated as registration numbers in the paperwork. After having been tested with little suc-cess as crop-dusters the civil D.H.9s were then assigned to photographic- work. Only three were actually sent on aerial photography missions in 1927 and one in 1928. All but four, which were re-registered CCCP-112 to CCCP-115, were then written off, the last example being cancelled in 1930. In 1928 the VVS offered Dobrolet twenty-eight additional D.H.9s, of which many were unserviceable, and a large number of extra wings, but the offer was refused.

Mercedes-engined D.H.9s used by Dobrolet
Reg Reg 1929 C/n In Service Notes
1 9152 2.27-6.29
2 CCCP-112 5826 4.27-29/30
3 1285 5.27-6.29 Crashed 11.28
4 2803 5.27-6.29
5 CCCP-113 5746 6.27-29/30
6 5778 7.27-6.29 Crashed 6.28
7 CCCP-114 5813 3.28-29/30
ДЛ-8 CCCP-115 9350 4.28-29/30
ДЛ-9 5821 3.28-6.29
ДЛ-10 5580 3.28-6.28 Crashed 22.6.28
ДЛ-11 5817 .29-29/30 Probably CCCP-116 ntu

   In addition to service with the reconnaissance units, the Puma-engined D.H.9s and Liberty-engined D.H.9As were also used as trainers, before they were withdrawn from the reconnaissance units in 1924. They remained until 1928, most with the 1st Higher School of Military Pilots in Moscow, but some were flown at the 2nd School of Military Pilots, the Strel'bom school, the Military School of Special Service, the Military-Technical School, the 83rd Training Eskadril'ya and the Akademiya VVS. A few were also assigned to the NOA.


D.H.9 (D.H.9A), original aircraft
   260hp Mercedes D.IVa (400hp Liberty 12)
   Span 12.94 (14) m; length 9.38 (9.22) m; height (3.45) m; wing area 40 (45.22) m2
   Empty weight 1,200 (1,270) kg; loaded weight 1,720 (2~100) kg
   Maximum speed 170 (193) km/h; landing speed 95 (90) km/h; climb to 1,000m in 6.5 (4) min; ceiling 4,580 (5,100) m; endurance 4 (5.5) hr; range 680 (750) km

A.Jackson British Civil Aircraft since 1919 vol.1 (Putnam)

De Havilland D.H.9A

   Contrary to general belief, the D.H.9A was not a conversion of the D.H.9, but an entirely different type of aeroplane. Its wings were of greater chord and span, the fuselage employed different methods of construction and the radiator was positioned in the nose, as in the D.H.4. This extensive redesign was carried out by the Westland Aircraft Works at Yeovil in 1918, and the vast majority of production aircraft were powered by the American 400-h.p. eight-cylinder Liberty engine. There were 13 British civil D.H.9As, but only three had this engine, the remainder being nonstandard.
   The first six were fitted with closely cowled 450-h.p. Napier Lion 12-cylinder engines, cooling being via an underslung radiator. These were actually R.A.F. machines registered to the British Government as G-EAOF - ’OK in October 1919 and loaned to Aircraft Transport and Travel Ltd. for the carriage of mail to the Army of Occupation on the Rhine. This service, begun by the R.A.F. on 17 December 1918, with standard D.H.9s, was handed over to A.T. & T. as a going concern on 15 August 1919. The difficult sector over the Ardennes and into Cologne called for machines of higher performance and load-carrying capacity. Thus for the last winter of the service a Lion engined fleet of 9As was provided, G-EAOH returning to the R.A.F. in April 1920 and the rest in the following June.
   Encouraged by the performance of the Lion-powered D.H.4R, the Aircraft Manufacturing Co. Ltd. built a similarly powered sesquiplane using D.H.9A components and designated the D.H.9R. In it Capt. Gathergood made a fast trip to Amsterdam in 2 hours 10 minutes when visiting the First Air Traffic Exhibition in July 1919. While there he won a closed circuit race at 145 m.p.h. On 15 November 1919 the same pilot broke several British speed records at Hendon, raising the closed-circuit record to 149-43 m.p.h.
   The other six D.H.9As were all surplus military stock, civilianized at Croydon by the Aircraft Disposal Co. Ltd. for demonstration or overseas delivery. The first, G-EAXC, converted in 1922, won the Club Handicap Race at the Croydon Easter Meeting 1922, flown by the A.D.C. test pilot Rex Stockem On 22 May he also flew ’XC in the race for the Coupe Lamblin over the course Le Bourget-Brussels-Croydon-Le Bourget and made fastest time. A second demonstration conversion G-EBCG appeared in April 1922, fitted with a 350-h.p. Rolls-Royce Eagle VIII engine for participation in the Croydon Whitsun Races. Cooling trouble resulted in the removal of the nose radiators and its replacement by smaller side radiators in time for the first King’s Cup Race, which started at Croydon on 8 September 1922. In this it was piloted by H. H. Perry, but forced-landed at Northolt with ignition trouble.
   This type of Eagle conversion was originally carried out on the military demonstrator G-EBAN, which was fitted with Lamblin radiators between the undercarriage legs. ’AN was despatched to Madrid in February 1922 to take part in the Spanish trials, where its performance resulted in an order for a batch of similar machines. The remaining three civil D.H.9As consisted of G-EBAC and ’LC, Liberty powered, flown overseas in 1922 and 1927 respectively, and G-EBGX fitted with a Napier Lion in 1923.


SPECIFICATION
Manufacturers: The Aircraft Manufacturing Co. Ltd., Hendon, London, N.W.9, and other contractors.
Power Plants: One 400-h.p. Liberty.
One 350-h.p. Rolls-Royce Eagle VIII.
One 450-h.p. Napier Lion.
Dimensions: Span, 45 ft. 11 j in. Length, 30 ft. 3 in. Height, 11 ft. 4 in. Wing area, 486-73 sq. ft.
Liberty Eagle VIII Lion
Tare weight 2,800 lb. 2,705 lb. 2,557 lb.
All-up weight 4,645 lb. 4,815 lb. 4,660 lb.
Speed at 10,000 ft. 114-5 m.p.h. 110-5 m.p.h. 134 m.p.h.
Initial climb 725 ft./min. 600 ft./min. 1,000 ft./min.
Ceiling 18,000 ft. 14,000 ft. 21,300 ft.
Duration 5 1/4 hours 3 1/2 hours -

Журнал Flight

Flight, January 9, 1919.

"MILESTONES"

THE DE HAVILLAND, OR "AIRCO," MACHINES

The D.H. 9a

   With the insistent demand for better and still better performance the necessity of fitting engines of greater power became urgent, and the D.H. 9A was produced to meet these demands. Except for the front portion of the body it was not greatly different from the D.H. 9. It has, however, a somewhat larger area, so as to obtain the same landing speed for the heavier weight. The object had in mind when designing the D.H. 9A was to provide an improvement on the 9, namely to carry a greater load while maintaining a high performance. Apart from being extremely useful for long-distance reconnaissance, photography and fighting, this machine has been largely used for long-distance day bombing raids. The accompanying table will give a good idea of the manner in which the designer succeeded in attaining his purpose, and it is of interest to mention the following facts in addition: By increasing the military load from 545 lbs. to 945 lbs. the speed at low altitudes is reduced to 125 m.p.h., and at 10,000 ft. to 114 1/2 m.p.h. The climb to 10,000 ft. with this load occupies 15.05 min. and the ceiling is 19,000 ft. The range is reduced to 620 miles. (The reduction in speed is largely due to the fact that the extra load in bombs is carried outside.) By way of showing the weight-carrying capacity of this machine it is of interest to note that it has flown successfully with a military load of 1325 lbs.
   A machine of this type has also been fitted with a 360 h.p. Rolls-Royce engine, and, carrying a military load of 1,745 lbs., reached a ceiling of 16.500 ft. with a speed of 107 1/2 m.p.h. at 10,000 ft. This machine differed from the standard 9A in that its petrol tankage was only 71 gallons, having a larger margin for load. It should also be noted that the above speed was reduced by about 4 m.p.h. owing to the bombs and carriers being put outside.

ПОЛИКАРПОВ Р-1

Как уже отмечалось, с 1921 года для пополнения авиационных частей начался выпуск небольшими сериями самолетов DH-4 и DH-9 (DH.4 и DH.9) на авиазаводе # 1. Общее руководство по внедрению этой машины осуществлял Н. Н. Поликарпов. Первоначально это были машины, почти полностью повторявшие английские аналоги и отличавшиеся только двигателями. Однако вынужденная замена ряда дефицитных материалов потребовала полностью пересмотреть проект, потому что самолет из отечественных материалов оказался тяжелее прототипа, а это повлекло за собой перерасчет прочности всей конструкции. Значительно упрощены стальные узлы крепления. Баки выполнялись из луженого железа толщиной 0,8 мм.
   Часть арматуры двигателя выполнялась из медного литья. Вместо красного дерева и ясеня применялась сосна. На этом самолете впервые началась отработка агрегатной сборки фюзеляжа (передняя, средняя и задняя часть стыковались стальными накладками на болтах).
   Лонжероны коробчатые - вместо двутавровых на D.H.9. Двигатель на основной модели - 12-цилиндровый, жидкостного охлаждения, рядный, V-образный М-5 (аналог "Либерти"). На самолете устанавливался лобовой сотовый радиатор. На самолетах, действовавших против басмачей в условиях пустыни, под двигателем подвешивался дополнительный радиатор. В целом, несмотря на некоторую переутяжеленность конструкции, самолет получился простым, прочным и дешевым.
   Весовая отдача Р-1 - 35,5% против 33,5 % у DH-9. На самолете устанавливались синхронный пулемет ПВ-1 (200 патронов) и такой же на турели (500 патронов). Под крылом подвешивались бомбы весом до 50 кг.
   В 1925 году на базе Р-1 был создан двухпоплавковый морской разведчик MP-I. Конструкция цельнодеревянных поплавков Н. Н. Поликарпова. Поплавки изготавливались из 3-мм (выше ватерлинии) и 4-мм (ниже ватерлинии) фанеры по каркасу из соснового бруса. Собирались поплавки на столярном клее и шурупах и покрывались "Кузбасс-лаком", а поверх него окрашивались. После поломки недостаточно прочных стоек на первом экземпляре МР-1 крепление поплавков было усилено. Число стоек доведено до 10 шт., а поплавки соединены между собой стальными трубами. Стойки изготавливались из стальных труб диаметром 60 мм с дюралевыми обтекателями.


Модификации
   Р-1 (DH-9) - около 100 машин, аналогичных DH-9, с двигателем "Даймлер" в 260 л.с. Причем несколько десятков этих самолетов, закуплены в Англии.
   P-2 (DH-9) - развитие предыдущего, с двигателем "Сиддли-Пума" (220л. с.). Построено 130 машин, практически не отличавшихся от прототипа.
   Р-1 М5 - массовая серия ставшего в ВВС РККА основным разведчиком и легким бомбардировщиком с двигателем М5 (400 л. с.). Всего выпущено 2800 самолетов.
   Р-1 "Лоррен-Дитрих" - опытный самолет с двигателем "Лоррен-Дитрих" (450 л. с.) и четырехлопастным винтом. Из-за большого лобового сопротивления и массы двигателя летные данные оказались хуже, чем у исходной модели.
   Р-2 с BMW-IVa - на снятых с вооружения 20 машинах Р-2 установили двигатели BMW-IVa (240 л. с.). Эти машины применялись в летных школах как тренировочные.
   МР-1 - 124 машины на поплавках конструкции Н.Н. Поликарпова для авиации ВМС с тем же двигателем, что и Р-1.
   МР-1 опытный - на цельнометаллических поплавках немецкого инженера Мюнцеля. Летные данные несколько лучше, чем у серийного МР-1, так как поплавки были легче. Серийно не строился из-за дефицита дюралюминия.


   Показатель DH-9 (Р-1) DH-9 (Р-2) Р-1 с М-5 МР-1
   1922г. 1923г. 1923г. 1925г.
   Размеры, м:
   длина 9,38 9,50 9,24 10,58
   размах крыльев 12,94 12,94 14,02 14,02
   высота 3,52 3,52 3,50 3,50
   Площадь крыла, м2 40,00 40,00 44,54 44,54
   Вес, кг:
   максимальный взлетный 1720 1730 2200 2580
   пустого 1200 1230 1450 1830
   Двигатель: "Даймлер" "Сиддли-Пума" М-5 М-5
   мощность, л. с. 260 220 400 400
   Скорость, км/ч 170 165 185 179
   Дальность полета, км 680 660 700 650
   Потолок практический, м 4580 4500 5000 3680
   Экипаж, чел. 2 2 2 2
   Вооружение 2 пулемета, 350 кг бомб