| Airco | |
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HW100 - 45000
UAW55 - 105000 RRW100 - 175000 PKRR - 7500 |
Airco The Aircraft Manufacturing Company Limited Industry - Aviation Founded - 1912 Defunct - 1920 Fate - Bankruptcy Successor - de Havilland Headquarters - The Hyde, Hendon, London, England Key people - Geoffrey de Havilland Products - Aircraft Subsidiaries - Aircraft Transport and Travel The Aircraft Manufacturing Company Limited (Airco) was an early British aircraft manufacturer. Established during 1912, it grew rapidly during the First World War, referring to itself as the largest aircraft company in the world by 1918. Airco produced many thousands of aircraft for both the British and Allied military air wings throughout the war, including fighters, trainers and bombers. The majority of the company's aircraft were designed in-house by Airco's chief designer Geoffrey de Havilland. Airco established the first airline in the United Kingdom, Aircraft Transport and Travel Limited, which operated as a subsidiary of Airco. On 25 August 1919, it commenced the world's first regular daily international service. Following the end of the war, the company's fortunes rapidly turned sour. The interwar period was unfavourable for aircraft manufacturers largely due to a glut of surplus aircraft from the war, while a lack of interest in aviation on the part of the British government also hampered its prospects. Airco quickly became unprofitable; during 1920, the firm was sold to Birmingham Small Arms Company, after which its operations were liquidated later that same year. Numerous assets and personnel formerly belonging to the company were integrated into the newly established de Havilland Aircraft Company. Origins and de Havilland During 1912, Airco was established by newspaper proprietor and industrialist George Holt Thomas. The firm was initially based at The Hyde in Hendon, north London, England. Starting in August 1914, the aviator William Taylor Birchenough worked as a test pilot for Airco. That same year, learning that Geoffrey de Havilland, who was then at the Royal Aircraft Factory in Farnborough, might be available, Holt Thomas invited him to join Airco as its chief designer. De Havilland's Airco designs would prove decisive to the company, which would eventually provide around 30 per cent of all trainers, fighters and bombers used by Britain and the United States during the First World War. De Havilland's designs for Airco were all marked with his initials "DH". Wartime production Airco would design and produce numerous aircraft during the wartime years. Its DH.2, a pusher configuration fighter introduced during 1916, contributed to ending the "Fokker scourge" of 1915. While early air combat over the Western Front had indicated the need for a single-seat fighter with forward-firing armament, there was no dominant approach to applying armaments to fighters at the time. As no means of firing forward through the propeller of a tractor aeroplane was available to the British, Geoffrey de Havilland designed the DH.2 as a smaller, single-seat development of the earlier two-seat DH.1 pusher design. A total of 453 DH.2s were produced by Airco. Another design produced by de Havilland was the DH.6, which was specifically designed as a military trainer; as this role was normally performed by obsolete service types at the time, it was an unconventional choice to develop a dedicated trainer. The DH.6 possessed relatively gentle flying characteristics, being described as being probably the most "forgiving" aircraft of its time, allowing itself to be flown "crab wise" in improperly banked turns and able to maintain sustained flight at speeds as low as 30 miles per hour (48 km/h). At least 2,282 DH.6s were built in the UK during wartime. The DH.4 was a two-seat combat aircraft, intended to perform both aerial reconnaissance and day bomber missions. By the end of production, a total of 1,449 aircraft (from orders for 1,700 aircraft) were constructed in Britain for the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). Production of the DH.4 was performed by a variety of companies beyond Airco themselves; these included F.W. Berwick and Co, Glendower Aircraft Company, Palladium Autocars, Vulcan Motor and Engineering, and the Westland Aircraft Work. Overseas, SABCA of Belgium produced a further 15 DH.4s during 1926. In the United States, several different manufacturers, including the Boeing Airplane Corporation, Dayton-Wright Airplane Company, the Fisher Body Corporation, and the Standard Aircraft Corporation produced an Americanised variant of the DH.4, featuring over 1,000 modifications from the original British design, to equip the American air services. During 1916, the DH.9 was designed as a successor to the DH.4, reusing both its wings and tail unit while adopting a modified fuselage that moved the pilot closer to the gunner/observer and away from the engine and fuel tank, which facilitated communication and was viewed as being a more optimal fighting configuration. However, While the DH.9 was deemed to be suitable for daytime bombing operations, it was found to be incapable of effective nighttime bombing due to the pilot's view being obstructed and visibility via the bombsight being unsuitable. The DH.9's performance in action over the Western Front was typically deemed to have been a disaster; heavy losses of the type were quickly incurred, attributed to both its poor performance and to engine failures, despite the prior derating of its engine to reduce the failure rate. By December 1918, Holt Thomas claimed in an advertisement that Airco was the largest aircraft company in the world, being engaged in the construction of aeroplanes, engines and propellers in large numbers, as well as a number of airships and flying boats. The engines being built included licensed production of Gnome and Le Rhone rotary engines. The company's works at Hendon employed between 7,000 and 8,000 people and had the latest metal-working machinery, in addition to extensive testing equipment, including a materials testing laboratory and a wind tunnel. At one stage, Airco was reportedly completing one new aircraft every 45 minutes on average. During 1920, the aviation periodical Flight Magazine reported that, during the period from August 1914 to November 1918, the D.H. Airco aircraft manufactured in both Britain and the United States had comprised approximately 30 per cent of the total output of aeroplanes of these two allies. Following the Armistice of 11 November 1918 and the end of the conflict, many of the wartime DH.4s and DH.9s, along with the improved DH.9A, served for many years with the newly created Royal Air Force. These aircraft also formed the basis of early de Havilland-designed airliners, including the company's DH.16 and DH.18 types which were operated by Aircraft Transport and Travel Limited, the first airline established in the United Kingdom, which was also owned by George Holt Thomas. Airline operations and the first daily international flights Airco decided to enter into the early airline business, established a dedicated subsidiary, Aircraft Transport and Travel (AT&T), for this purpose. On 25 August 1919, the firm commenced the world's first regular daily international service, between Hounslow Heath Aerodrome and Le Bourget Aerodrome, France. A number of DH.16s were used for this service. In addition to operating the London-to-Paris service, AT&T also launched other routes, including one between Croydon Airport and Amsterdam, on behalf of the Dutch airline KLM. On 17 May 1920, an AT&T DH.16 (G-EALU) performed the first KLM service between London and Amsterdam. Sale to BSA and liquidation Following the cessation of hostilities, the large number of war-surplus machines, sharp fluctuations in business confidence, and the government's failure, unlike those of USA and France, to provide any form of support, Airco became unprofitable. Thomas endeavoured to sell Airco to a car manufacturer. Airco and BSA, parent company of Daimler, announced on 1 March 1920 that Airco had amalgamated with Birmingham Small Arms Company. Within days BSA discovered Airco was in a far more serious financial state than Thomas had revealed. Thomas was immediately removed from his new seat on the BSA board and all BSA's new acquisitions were placed in liquidation. As a result of the financial situation that it inherited, BSA was unable to issue a dividend to shareholders for the following four years. With help from Thomas, de Havilland bought the group's assets he needed to form the de Havilland Aircraft Company during 1920. Aircraft Transport and Travel had been allowed to continue to operate until December 1920. BSA then bought Aircraft Transport and Travel's aircraft from the liquidator and, in early 1921, established Daimler Airway and Daimler Air Hire under Daimler Hire Limited's Frank Searle. List of Airco aircraft Airco DH.1:(1915) - Two-seat biplane fighter with single pusher propeller. Airco DH.1A - Around 70 built with Beardmore engines. Airco DH.2 (1915) - Single-seat biplane fighter with single pusher propeller. Airco DH.3 (1916) - Twin-engine biplane bomber. Two prototypes only built; formed basis for later DH.10 design. Airco DH.3A - Second prototype with a Beardmore engine. Airco DH.4 (1916) - Two-seat biplane day bomber with single tractor propeller. Airco DH.4A Civil version. Built in the United Kingdom. Two passengers in glazed cabin behind pilot. Airco DH.4R Single seat racer - 450 hp (3406 kW) Napier Lion engine. Airco DH.5 (1916) - Single-seat biplane fighter with single tractor propeller. Airco DH.6 (1916) - Two-seat biplane training aircraft with single tractor propeller. Airco DH.9 (1917) - Two-seat biplane day bomber with single tractor propeller. Airco DH.9A (1918) - development of DH.9 with Liberty engine. Airco DH.9C (1921) - conversion of DH.9 as passenger aircraft. Airco DH.10 Amiens (1918) - Twin-engine biplane bomber. First prototype used pusher propeller; second prototype and production aircraft used tractor propellers. Manufactured by Daimler. DH.11 Oxford (1919) Variant of DH.10 with radial engines. One prototype built; not produced. Airco DH.15 Gazelle (1919) - One DH.9A aircraft converted into an engine test-bed. Airco DH.16 (1919) - redesign of DH.9A with cabin for four passengers. Used as airliner. Airco DH.18 (1920) - Single-engine biplane airliner. Cabin for eight passengers. Airco DH.16 used by Aircraft Transport and Travel "The Aircraft Manufacturing Company's new high-speed Aeroplane for two passengers, fitted with a 360 h.p. Rolls-Royce engine. Speed 130 miles an hour." (1919) Airco DH.1 DH.1 Role - Two-seat fighter / General-purpose aircraft National origin - United Kingdom Manufacturer - Airco Designer - Geoffrey de Havilland First flight - January 1915 Introduction - 1915 Retired - 1918 Primary user - Royal Flying Corps Number built - 100 The Airco DH.1 was an early military biplane of typical "Farman" pattern flown by Britain's Royal Flying Corps during World War I. By the time the powerplant for which it was designed was sufficiently plentiful it was obsolete as an operational aircraft, and apart from a few examples sent to the Middle East it served as a trainer and Home Defence fighter. Design and development Geoffrey de Havilland was one of the pioneering designers at the Royal Aircraft Factory and was partially or wholly responsible for most prewar "Factory" designs. When he left to become chief designer at The Aircraft Manufacturing Company (Airco) in 1914, his first design was strongly reminiscent of the F.E.2, one of the last designs on which he had worked at the Royal Aircraft Factory. Like the F.E.2, the DH.1 was of pusher configuration, accommodating its pilot and observer in two open tandem cockpits in the nose. The observer's cockpit was stepped down below the pilot's and equipped with a machine gun. The wings were of typical fabric-covered, two-bay, unstaggered, unswept, equal span design, while the stabiliser and rudder were carried on the end of two long, open-framework booms. The type, like the F.E.2b, was designed for the water-cooled Beardmore 120 hp (89 kW) inline engine. [Other sources state that the intended engine was the 100 hp (75 kW) Green.] However, all available Beardmore engines were required for F.E.2b and R.E.5 production, so the air-cooled Renault 70 hp (52 kW) V8 engine was installed instead. The prototype was fitted with aerofoils attached to the side of the nacelle which could be rotated through 90 degrees to act as air brakes, an unusual feature for the time, although they were soon removed. It had a fixed conventional landing gear with the mainwheels carried on V-struts, using coil springs and oleos for the suspension. In January 1915 Geoffrey de Havilland piloted the D.H.1 prototype on its first flight at Hendon. Although the Renault engine left it underpowered, performance was still reasonable and the type was ordered into production, with an initial order of 49 being placed. Airco was already occupied with building and designing other aircraft, so DH.1 production was undertaken by Savages Limited of King's Lynn, which had previously manufactured fairground equipment. [It was not uncommon in the First World War for factories that had little background in the aviation industry, but were able to utilize experience in related manufacture, including cabinet making, to undertake aircraft production.] These aircraft used a simpler rubber cord suspension, and had a revised cockpit coaming to give a better field of fire for the observer's gun. Production was initially very slow, and only five examples of the type had reached the RFC by the end of 1915. Later production machines were fitted with the Beardmore engine, as originally intended, as these had become more plentiful. This version was redesignated the DH.1A. Although testing of the DH.1A showed it to be at least as good as the F.E.2b, this was hardly a recommendation, as the F.E. was itself already slated for replacement with more modern tractor types. Nonetheless, a further order for 50 DH.1As was placed with Savages. [Although all of the second batch were completed, only 73 DH.1s were issued to RFC units.] By the time of the DH.1's first flight, a single-seat "follow-up" was already being considered; and by June 1915 the first D.H.2 had already made its maiden flight. Designed essentially as a smaller version of the D.H.1, the D.H. 2 was to become of one of the most important British fighters of the period. Operational history The DH.1 saw operational service only in the Middle East theatre, where six Beardmore-powered DH.1As arrived in July 1916. These were used by No. 14 Squadron RFC as escorts for their B.E.2 reconnaissance aircraft. An Aviatik two-seater was claimed by a 14 Squadron D.H.1A on 2 August 1916 for the only known victory of the type. The last known action by a DH.1 was on 5 March 1917, when one was shot down during a bombing raid on Tel el Sheria. No. 14 Squadron became an R.E.8 unit in November 1917; it seems probable that the last operational DH.1 had gone before that date. The other DH.1s served in training, with 43 aircraft allotted and Home Defence units in the United Kingdom receiving an additional 24 aircraft, finally being withdrawn from service in 1918. Variants DH.1 - Prototype and early-production aircraft powered by 70hp Renault engine DH.1A - Some 70 production examples powered by a 120hp Beardmore engine Total production was one prototype and 99 DH.1 and DH.1As, all production examples built by Savages. Operators - Australia Australian Flying Corps (No. 1 Squadron AFC operated a single aircraft (no. 4620) from June to July 1916) - United Kingdom Royal Flying Corps (No. 14 Squadron RFC) Specifications (DH.1) (Data from De Havilland Aircraft since 1909) General characteristics Crew: two (pilot and observer) Length: 28 ft 11+5⁄8 in (8.830 m) Wingspan: 41 ft 0 in (12.50 m) Height: 11 ft 4 in (3.45 m) Wing area: 426+1⁄4 sq ft (39.60 m2) Empty weight: 1,356 lb (615 kg) Gross weight: 2,044 lb (927 kg) Powerplant: 1 × Renault Type W air-cooled V-8, 70 hp (52 kW) Propellers: wood fixed pitch propeller Performance Maximum speed: 80 mph (130 km/h, 70 kn) Rate of climb: 350 ft/min (1.8 m/s) Wing loading: 4.7 lb/sq ft (23 kg/m2) Armament Guns: 1 × 0.303 in (7.7 mm) Lewis machine gun for observer Prototype DH.1A 3-view Airco DH.2 Airco DH.2 Role - Fighter Manufacturer - Airco Designer - Geoffrey de Havilland First flight - July 1915 Retired - 1918 Primary user - Royal Flying Corps Number built - 453 Developed from - Airco DH.1 The Airco DH.2 was a single-seat pusher biplane fighter aircraft which operated during the First World War. It was the second pusher design by aeronautical engineer Geoffrey de Havilland for Airco, based on his earlier DH.1 two-seater. The development of pusher configuration fighters, such as the DH.2 and the F.E.2b enabled forward firing armament before the development of synchronisation gears such as that fitted to the German Fokker Eindecker monoplane fighter. The prototype DH.2 made its first flight in July 1915, but it was lost during the following month, on its service trials on the Western Front. The DH.2 was introduced to frontline service in February 1916 and became the first effectively armed British single-seat fighter. It enabled Royal Flying Corps (RFC) pilots to counter the "Fokker Scourge" that had given the Germans the advantage during late 1915. It served in fighting and escort duties for almost two years, while numerous pilots became flying aces using the type. It became outclassed by newer German fighters, resulting in the DH.2's eventual withdrawal from first line service in France after RFC units completed the process of re-equipping with newer fighters, such as the Nieuport 17 and Airco DH.5, in June 1917. Development By the outbreak of the First World War, aeronautical engineer Geoffrey de Havilland was already an experienced aircraft designer, having been responsible for the experimental Royal Aircraft Factory F.E.1, Royal Aircraft Factory F.E.2 and Blériot Scout B.S.1, the B.S.1 being the fastest British aircraft of its day. In June 1914, de Havilland left the Royal Aircraft Factory for Airco, where he continued work on his own designs, the first being the Airco DH.1, which followed a similar formula to that of the F.E.2. Early air combat over the Western Front indicated the need for a single-seat fighter with a forward-firing machine gun. At this point in time, there was no dominant approach to arming fighters, but a pusher configuration was one answer. As no means of firing forward through the propeller of a tractor aeroplane was yet available to the British, Geoffrey de Havilland designed the DH.2 as a scaled-down, single-seat development of the earlier two-seat DH.1. Aviation author J.M Bruce speculated that, had adequate synchronisation gear been available, de Havilland may have been less likely to pursue a pusher configuration. While it is popularly viewed as a response to the emergence of Germany's Fokker Eindecker monoplane fighters, its development was not specifically targeted at the type, having commenced prior to the Eindecker's arrival. The first prototype DH.2 performed its first flight in July 1915. Following the completion of its manufacturing trials, on 26 July 1915, the prototype was dispatched to France for operational evaluation, but was lost over the Western Front and was captured by the Germans. Despite the prototype's premature loss, the DH.2 was ordered into quantity manufacture. The production aircraft was generally similar to the prototype with the only major alterations being a fuel system and a revised gun mounting arrangement. Deliveries of the DH.2 commenced during the latter half of 1915 and a handful of aircraft were reportedly operating in France prior to the year's end. A total of 453 DH.2s were produced by Airco. Design The Airco DH.2 was a compact two-bay pusher biplane fighter aircraft. It had a wooden airframe, which was wire-braced and covered by fabric across most areas, except for the nacelle nose and upper decking. Both the upper and lower wings had ailerons fitted. The upper ailerons were spring-loaded to automatically return to a neutral position when the controls were released. The upper part of the nose of the nacelle was cut away so that a machine gun could be mounted there. Unusually, the windshield was mounted on the machine gun rather than to the airframe. The DH.2 was armed with a single .303 in (7.7 mm) Lewis gun which was mounted on a flexible mount. Once pilots learned that the best method of achieving a victory was to aim the aircraft rather than the gun, it was fixed to fire forward, although this was met with skepticism by higher authorities until a quick-release clip was devised at the Squadron level. The clip was devised by Major Lanoe Hawker, who also improved the gunsights and added a ring sight and an "aiming off model" that helped the gunner allow for leading a target. The majority of DH.2s were powered by the 100 hp (75 kW) Gnôme Monosoupape nine-cylinder, air-cooled rotary engine, however later models received the similarly configured but much improved 110 hp (82 kW) Le Rhône 9J engine. Some sources state that the Monosoupape was retained in the DH.2 design despite a tendency to shed cylinders midair and a single DH.2 was fitted experimentally with a Le Rhône 9J. In addition to the variety of engines used, the fuel system also differed between individual aircraft. Typically, a gravity-fed fuel tank was used, but it could be located on the upper wing central section, or either above or below the port side upper wing. Operational service After evaluation at Hendon on 22 June 1915, the first DH.2 arrived in France for operational trials with No. 5 RFC Squadron but was shot down and its pilot killed during early August 1915. This aircraft was recovered and repaired by the Germans. The first squadron equipped with the DH.2, and the first RFC squadron completely equipped with single-seat fighters, No. 24 Squadron RFC, arrived in France early February 1916. The DH.2 eventually equipped seven fighter squadrons on the Western Front and proved more than a match for the Fokker Eindecker and the first DH.2 victory over an Eindecker may have been on 2 April 1916. DH.2s were heavily involved in the Battle of the Somme with No. 24 Squadron engaging in 774 combats and claiming 44 enemy machines. Service training for pilots in the RFC was poor, and the DH.2 initially had a high accident rate, supposedly gaining the nickname "The Spinning Incinerator", but as familiarity with the type improved, it was recognised as being maneuverable and relatively easy to fly. The limited ammunition supply of the original gun installation proved to be inadequate. Although officially discouraged, pilots experimented with different gun arrangements, including a fixed twin-gun configuration. Furthermore, the original gun mounting was criticised for being loose and unstable, and it obstructed the stick when elevated. DH.2s were routinely flown with the guns fixed into position. The arrival at the front of more powerful German tractor biplane fighters such as the Halberstadt D.II and the Albatros D.I, in late 1916, meant that the DH.2 was outclassed in turn. It remained in first line service until June 1917 in France, until No. 24 and No. 32 Squadron RFC reequipped with Airco DH.5s, and a few remained in service in Macedonia including "A" Flight of No. 47 Squadron and a joint R.F.C. / R.N.A.S. fighter squadron, and with "X" Flight, in Palestine until late 1917. By then, it was dangerously obsolete as a fighter. The DH.2 was then used as an advanced trainer and for other secondary tasks, with the last recorded use of a DH.2 being a single example flying at RAF Turnhouse in January 1919. Ace pilots Distinguished pilots of the DH.2 included Victoria Cross recipient Lanoe Hawker (seven victories, though none in the DH.2), who was the first commander of No. 24 Squadron. The commander of No. 32 Squadron, Lionel Rees was awarded the Victoria Cross after flying the D.H.2 for a solo attack on a formation of ten German two-seaters on 1 July 1916, destroying two. James McCudden became an ace in DH.2s and would become the British Empire's fourth-ranking ace of the war. German ace and tactician Oswald Boelcke was killed during a dogfight with No. 24 Squadron DH.2s due to a collision with one of his own wingmen. Fourteen aces scored five or more aerial victories using the DH.2 and many also went on to further success in later types. Eight pilots scored all of their victories in the DH-2, including Harry Wood, Sidney Cowan, Hubert Jones, William Curphey, Maxmillian Mare-Montembault, Patrick Anthony Langan-Byrne, Eric Pashley and Selden Long. Lanoe George Hawker V.C., D.S.O., and commanding officer of No. 24 Squadron flying a DH. 2 was shot down by Manfred von Richthofen flying an Albatros D.II. DH.2 aces Pilot - victories Patrick Anthony Langan-Byrne - 10 Alan Wilkinson - 10 Selden Long - 9 Arthur Gerald Knight - 8 Eric C. Pashley - 8 John Oliver Andrews - 7 Sidney Cowan - 7 Hubert Jones - 7 William Curphey - 6 Stanley Cockerell - 5 Henry Evans - 5 James McCudden - 5 Robert Saundby - 5 Harry Wood - 5 Reproductions No original DH.2s exist. In 1970, Walter M. Redfern from Seattle, Washington built a replica DH.2 called the Redfern DH-2, powered by a Kinner 125-150 hp (93-112 kW) engine. Redfern subsequently sold plans to home builders, and several of these replicas are flying. Redfern's original replica is now displayed at the Omaka Aviation Heritage Centre in Blenheim, New Zealand. Operators 1. United Kingdom - Royal Flying Corps (Most units operated the DH.2 alongside other types) No. 5 Squadron RFC No. 11 Squadron RFC No. 17 Squadron RFC No. 18 Squadron RFC No. 24 Squadron RFC No. 29 Squadron RFC No. 32 Squadron RFC No. 41 Squadron RFC No. 47 Squadron RFC No. 111 Squadron RFC Specifications (DH.2) (Data from Warplanes of the First World War - Fighters Volume One) General characteristics Crew: 1 Length: 25 ft 2+1⁄2 in (7.684 m) Wingspan: 28 ft 3 in (8.61 m) Height: 9 ft 6+1⁄2 in (2.908 m) Wing area: 249 sq ft (23.1 m2) Empty weight: 943 lb (428 kg) Gross weight: 1,441 lb (654 kg) Powerplant: 1 × Gnôme Monosoupape 9-cylinder rotary engine, 100 hp (75 kW) Propellers: 2-bladed Integral DG 70 fixed pitch wooden propeller Performance Maximum speed: 93 mph (150 km/h, 81 kn) at sea level Endurance: 2 hours, 45 minutes Service ceiling: 14,000 ft (4,300 m) Time to altitude: 24 minutes, 45 seconds to 10,000 ft (3,000 m) Armament Guns: 1 × .303 in (7.7 mm) Lewis gun Rockets: Two examples were equipped with Le Prieur rockets for attacking observation balloons See also Nieuport 10 Nieuport 11 Nieuport 16 Related development Airco DH.1 Redfern DH-2 (replica) Aircraft of comparable role, configuration, and era Avro 508 Port Victoria P.V.4 Royal Aircraft Factory F.E.8 Vickers F.B.12 Rear view of a reproduction DH.2 Early DH.2 taking off from airfield at Beauvel, France 32 Squadron RFC personnel, in front of a DH.2 at Beauval, 1916 DH.2 Reproduction on display at the Omaka Aviation Heritage Centre Airco DH.2 drawing Airco DH.3 DH.3 Role - Biplane bomber Manufacturer - Airco Designer - Geoffrey de Havilland First flight - before May 1916 Status - Prototype Number built - 2 Developed into - Airco DH.10 Amiens The Airco DH.3 was a British bomber aircraft of the First World War. The DH.3 was designed in 1916 as a long-range day bomber by Geoffrey de Havilland, chief designer at the Aircraft Manufacturing Company. It was a large biplane with wide-span three-bay wings, slender fuselage, and a curved rudder. It was powered by two 120 hp (89 kW) Beardmore engines, mounted as pushers between the wings. In addition to tailskid landing gear, two wheels were placed under the nose to prevent it from tipping over on the nose. A second prototype, designated DH.3A, was built with more powerful 160 hp (120 kW) Beardmore engines, and the War Office placed a production order for 50. This order was cancelled before any could be completed, possibly because the climb rate was still far too low, with it taking 58 minutes to reach 6,500 feet, and the other contender, the Royal Aircraft Factory F.E.4 was even worse, which made strategic bombing with these machines impracticable. The two prototypes were scrapped in 1917. The DH.10 Amiens was developed from the DH.3A with much more powerful engines (boosting installed power from 320 hp (240 kW) to nearly 800 hp (600 kW)) and some detail changes were made. This development first flew in March 1918, but was too late to see squadron service during the war. Specifications (DH.3) (Data from De Havilland Aircraft since 1909) General characteristics Crew: three Length: 36 ft 10 in (11.23 m) Wingspan: 60 ft 10 in (18.54 m) Height: 14 ft 6 in (4.42 m) Wing area: 793 sq ft (73.7 m2) Empty weight: 3,980 lb (1,805 kg) Gross weight: 5,810 lb (2,635 kg) Powerplant: 2 × Beardmore 120 hp water-cooled straight-six engines, 120 hp (89 kW) each Propellers: 4-bladed wood fixed pitch propeller, 9 ft 6 in (2.90 m) diameter Performance Maximum speed: 95 mph (153 km/h, 83 kn) Range: 700 mi (1,100 km, 610 nmi) Endurance: 8 hr Rate of climb: 550 ft/min (2.8 m/s) Armament Guns: 2 × flexibly mounted .303 in (7.7 mm) Lewis guns Bombs: up to 680 lb (310 kg) bombs Related development Airco DH.10 Amiens Aircraft of comparable role, configuration, and era Nieuport London Vickers Vimy Airco DH.3 Airco DH.4 DH.4 Role - Light bomber / General purpose Manufacturer - Airco Built by - Boeing Airplane Corporation / Dayton-Wright Company / Fisher Body / Standard Aircraft Corporation First flight - August 1916 Introduction - March 1917 Retired - 1932 (United States Army Air Service) Status - Retired Primary users - Royal Flying Corps / Royal Air Force / Royal Naval Air Service / United States Army Air Service Number built - 6,295, of which 4,846 were built in the United States Variants - Airco DH.9 / Airco DH.9A / Dayton-Wright Cabin Cruiser The Airco DH.4 is a British two-seat biplane day bomber of the First World War. It was designed by Geoffrey de Havilland (hence "DH") for Airco, and was the first British two-seat light day-bomber capable of defending itself. It was designed and developed specifically as a bomber, as well as aerial reconnaissance missions. The DH.4 was to have been powered by the new 160 hp (120 kW) Beardmore Halford Pullinger (BHP) engine, but problems with that resulted in numerous other engines being used, perhaps the best of which was the 375 hp (280 kW) Rolls-Royce Eagle engine. The DH.4 first flew in August 1916 and it entered operational service in France on 6 March 1917 less than a year later. The majority were manufactured as general purpose two-seaters in the United States for the American expeditionary forces in France, becoming the only American made plane to see combat in WW1. Following the Armistice of 11 November 1918, many DH.4s were sold to civil operators where it was found to be particularly useful as a mailplane. Early commercial passenger airplane service in Europe was initiated with modified variants of the DH-4. War-surplus DH-4s became key aircraft in newly emerging air forces throughout the world. The U.S. Army later had several companies re-manufacture its remaining DH.4s to DH.4B standard and they operated the type into the early 1930s. Development Origins The DH.4 was designed by Geoffrey de Havilland as a light two-seat combat aircraft, intended to perform both day bomber and aerial reconnaissance missions. The intention was for it to be powered by the newly-developed 160 hp (120 kW) Beardmore Halford Pullinger (BHP) engine. The DH.4 was developed in parallel to the rival Bristol Fighter. During August 1916, the prototype DH.4 made its first flight, powered by a prototype 230 hp (170 kW) BHP engine. Initial flight tests revealed it to have favourable handling and performance. The Central Flying School (CFS) conducted early evaluation flights using the prototype, leading to it producing a favourable report on the aircraft, observing good stability in flight, light flying controls and its relatively comfortable crew positions. During its flights with the CFS, it was able to attain previously unheard-of time-to-altitude figures, unmatched by any of its predecessors. While flying trials with the prototype had been producing promising results, it soon became clear that the BHP engine would require a major redesign prior to entering production. Even by the time of flying trials with the first prototype, there had been no finalised plans for quantity production of the BHP engine. Coincidentally, another suitable and promising aeroengine, the water-cooled Rolls-Royce Eagle in-line engine, was approaching the end of its development process. According to Bruce, the Eagle shared the same basic configuration as the BHP engine, which greatly aiding in its adoption by de Havilland, as did the engine's endorsement by William Beardmore. During the summer of 1916, a second prototype, equipped with the Rolls-Royce engine, conducted its first flight. In response to its favourable performance, the Royal Flying Corps (RFC) decided to place an initial order for the type during late 1916. Separately to the RFC's interactions with the DH.4, it had received substantial interest from the Royal Navy as well. The Admiralty decided to order a further pair of prototypes, configured to suit the service's own requirements, for evaluation purposes; however, according to Bruce, it is unlikely that the second of these was ever constructed. Following trials with the first of these prototypes, orders were placed for the production of DH.4s to equip the Royal Naval Air Service. Production During late 1916, the first order for 50 DH.4s, powered by 250 hp (190 kW) Eagle III engines, was received from the RFC. According to Bruce, it was not a surprise to most observers that the Eagle had been selected to power the first batch of production DH.4s. The initial production aircraft were largely identical to the second prototype, the main difference being the adoption of armament, which included a single synchronised 0.303 in (7.7 mm) Vickers machine gun for the pilot, while the observer was provided with a 0.303 in (7.7 mm) Lewis gun mounted upon a Scarff ring. Production of the DH.4 was performed by a variety of companies beyond Airco themselves; these included F.W. Berwick and Co, Glendower Aircraft Company, Palladium Autocars, Vulcan Motor and Engineering, and the Westland Aircraft Works. By the end of production, a total of 1,449 aircraft (from orders for 1,700 aircraft) were constructed in Britain for the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). Overseas, SABCA of Belgium produced a further 15 DH.4s during 1926. As production progressed, various changes and improvements to the design were introduced upon the DH.4. As time went on, production DH.4s were fitted with Eagle engines of increasing power, ending with the 375 hp (280 kW) Eagle VIII, which powered the majority of frontline DH.4s by the end of 1917. However, this transition was greatly hindered as by January 1917, it had become clear that there was a chronic shortage of Rolls-Royce aero engines, and of the Eagle in particular; it has been claimed by Bruce that this shortfall was partially the result of protracted decision-making on the part of the Air Board. In response to the limited availability of the Eagle, extensive investigations into the use of alternative engines for the DH.4 were conducted. This resulted in aircraft being outfitted with a diverse range of engines; these included the BHP (230 hp (170 kW), the Royal Aircraft Factory RAF3A (200 hp (150 kW)), the Siddeley Puma (230 hp (170 kW)) and the 260 hp (190 kW) Fiat, all of which were used to power, which encountered varying degrees of success, to production aircraft. None of these engines proved to be capable of matching the performance of the Eagle engine, which remained the preferred options despite the persistent supply constraints. American versions At the time of entry of the United States into the First World War on 6 April 1917, the aviation section of the U.S. Signal Corps was unprepared, not being equipped with any aircraft suitable for combat. However, considerable optimism and energy was put into addressing this identified need, leading to the mobilization of American industry to set about the production of contemporary combat aircraft. As there were no suitable aircraft domestically, a technical commission, known as the Bolling Commission, was dispatched to Europe to seek out the best available combat aircraft and to make arrangements to enable their production to be established in the United States. As a result of the efforts of the Bolling Commission, the DH.4, along with the Bristol F.2 Fighter, the Royal Aircraft Factory S.E.5, and French SPAD S.XIII were selected. On 27 July 1917, a single DH.4 was sent to the United States as a pattern aircraft. It was not until 1918 that the first American-built DH.4s came off the production line. Several different manufacturers, including the Boeing Airplane Corporation, Dayton-Wright Company, the Fisher Body Corporation, and the Standard Aircraft Corporation produced this Americanized variant of the DH.4, featuring over 1,000 modifications from the original British design, to equip the American air services. A total of 9,500 DH.4s were ordered from American manufacturers, of which 1,885 actually reached France during the war. In American production, the new Liberty engine, which had proved suitable as a DH.4 power plant, was adopted. The Liberty was also eventually adopted by the British to power the DH.9A variant of the type. After the war, a number of firms, most significant of these being Boeing, were contracted by the U.S. Army to remanufacture surplus DH.4s to the improved DH.4B standard. Internally referred to by Boeing as the Model 16, deliveries of 111 aircraft from this manufacturer took place between March and July 1920; reportedly, roughly 50 of these were returned for further refurbishments three years later. During 1923, the Army placed an order for a new DH.4 variant from Boeing, distinguished by a fuselage of fabric-covered steel tube in place of the original plywood structure. These three prototypes were designated DH.4M-1 (M for modernized) and were ordered into production alongside the generally similar DH.4M-2 developed by Atlantic Aircraft. A total of 22 of the 163 DH.4M-1s were converted by the Army into dual-control trainers (DH.4M-1T) and a few more into target tugs (DH.4M-1K). Thirty of the aircraft ordered by the Army were diverted to the Navy for Marine Corps use, these designated O2B-1 for the base model, and O2B-2 for aircraft equipped for night and cross-country flying. Design The Airco DH.4 was a conventional tractor two bay biplane of all-wooden construction. It was entirely built of traditional materials. The forward fuselage section and the underside of the tail area was covered by a 3mm plywood skin; this construction led to the fuselage being both strong and lightweight, heavily contributing to cross-bracing only being used for the four bays directly behind the rear cockpit. The nose of the aircraft was considerably longer than necessary, the cowling having been originally designed to accommodate the Beardmore Halford Pullinger (BHP) engine, rather than the Rolls-Royce Eagle that was adopted for production instead. The DH.4 was powered by a variety of engines, including the Eagle, the BHP, the American Liberty, Royal Aircraft Factory RAF3A, the Siddeley Puma and the Fiat. Regardless of the engine used, it drove a four-bladed propeller mounted upon the nose. Cooling for the engine was provided via an oval-shaped radiator, while a port-mounted exhaust manifold discarded waste emissions above the upper wing. An unusual modification featuring on a small proportion of production DH.4s was the inversion of the engine, a design change that had been implemented in order to better accommodate the relatively-tall Ricardo-Halford-Armstrong (RHA) supercharged engine, which would otherwise unduly obstruct the pilot's forward field of view. The DH.4 was operated by a crew of two, who were accommodated in widely spaced cockpits, between which the fuel tank was positioned. While the crew arrangement provided good fields of view for both the pilot and observer; however, it had the noticeable downside of causing communication problems between the two crew members, particularly during combat situation, where the speaking tube that linked the two cockpits was of only limited use. On the majority of American-built aircraft, the pilot's seating and fuel tank arrangement were switched around; aviation author Peter M Bowers credits this change with improving the pilot's safety in the event of a crash, as well as allowing for better communication with the observer. The DH.4 was armed with a single forward-firing synchronised Vickers machine gun along with either one or two .303 in (7.7 mm) Lewis guns fitted on a Scarff ring fired by the observer. In terms of bomb load, it accommodate a maximum payload of 460 lb (210 kg), which could be mounted upon external racks. Throughout the type's production life, a number of alterations to the armaments, such as the ergonomics of the observer's Lewis gun and the installation of an additional Vickers gun, were implemented. A pair of DH.4s were outfitted with COW 37 mm guns for experimental purposes, but the war came to a close prior to firing trials being conducted. All armaments would typically be removed from those DH.4s that were used by civil operators, including ex-military aircraft that were sold on in great numbers following the end of the Great War. One of the more elaborate modifications of the DH.4 was the adaption of the type as a seaplane. It was furnished with large floats, which were allegedly based upon the design of those used upon the German Hansa-Brandenburg W.29 seaplane. According to Bruce, while no such aircraft entered into operational service as a result of competition from other aircraft to perform the role, a number of DH.4 seaplanes were produced for trial purposes at Felixstowe and were successfully flown. Operational history British military service The DH.4 entered service with the RFC in January 1917, first being used by No. 55 Squadron. More squadrons were equipped with the type to increase the bombing capacity of the RFC, with two squadrons re-equipping in May, and a total of six squadrons by the end of the year. During late 1917, the uptake of the type by the RFC was accelerated due to a desire to launch retaliatory bombing raids upon Germany following such attacks having been conducted against the British mainland. While Russia had been an early customer for the DH.4, having ordered 50 of the type in September 1917, the Russian and British governments subsequently agreed to delay the former's deliveries, instead diverting those aircraft to RFC squadrons in France. As well as the RFC, the RNAS also used the DH.4. During the spring of 1917, No. 2 Squadron became the first unit of the service to receive examples of the type. The RNAS flew their DH.4s over both France and over Italy, specifically the Aegean front in the latter case. The DH.4 was typically used to conduct coastal patrols by the RNAS. One such flight, crewed by the pilot Major Egbert Cadbury and Captain Robert Leckie (later Air Vice-Marshal) as gunner, shot down Zeppelin L70 on 5 August 1918. In another incident, a group of four RNAS DH.4s were jointly credited with the sinking of the German U-boat UB 12 on 19 August 1918. The DH.4 proved a huge success and was often considered the best single-engined bomber of World War I. (Quote: "Certainly the DH.4 was without peer among the day-bombing aeroplanes used by the aerial forces of any of the combatant nations.") Even when fully loaded with bombs, with its reliability and impressive performance, the type proved highly popular with its crews. The Airco DH.4 was easy to fly, and especially when fitted with the Rolls-Royce Eagle engine, its speed and altitude performance gave it a good deal of invulnerability to German fighter interception, so that the DH.4 often did not require a fighter escort on missions, a concept furthered by de Havilland in the later Mosquito of the Second World War. A drawback of the design was the distance between pilot and observer, as they were separated by the large main fuel tank. This made communication between the crew members difficult, especially in combat with enemy fighters. There was also some controversy (especially in American service) that this placement of the fuel tank was inherently unsafe. In fact, most contemporary aircraft were prone to catching fire in the air. (Sometimes derided as the "Flaming Coffin," Gorrell's History of the Air Service of the AEF refuted the misconception. Quote: "Of 33 DH-4s lost to enemy action by the US Air Service, eight fell in flames- no worse than the average at the time.") The fire hazard was reduced, however, when the pressurised fuel system was replaced by one using wind-driven fuel pumps late in 1917, although this was not initially adopted by American-built aircraft. The otherwise inferior DH.9 brought the pilot and observer closer together by placing the fuel tank in the usual place, between the pilot and the engine. Despite its success, numbers in service with the RFC actually started to decline from spring 1918, mainly due to a shortage of engines, and production switched to the DH.9, which turned out to be disappointing, being inferior to the DH.4 in most respects. It was left to the further developed DH.9A, with the American Liberty engine, to satisfactorily replace the DH.4. When the Independent Air Force was set up in June 1918 to carry out strategic bombing of targets in Germany, the DH.4s of 55 Squadron formed part of it, being used for daylight attacks. 55 Squadron developed tactics of flying in wedge formations, bombing on the leader's command and with the massed defensive fire of the formation deterring attacks by enemy fighters. Despite heavy losses, 55 Squadron continued in operation, the only one of the day bombing squadrons in the Independent Force which did not have to temporarily stand down owing to aircrew losses. After the Armistice, the RAF formed No. 2 Communication Squadron, equipped with DH.4s to carry important passengers to and from the Paris Peace Conference. Several of the DH.4s used for this purpose were modified with an enclosed cabin for two passengers at the request of Bonar Law. One of these planes was extensively used by Prime Minister David Lloyd George and was sometimes called Lloyd George's airplane - probably the first aeroplane widely used by a political leader. Modified aircraft were designated DH.4A, with at least seven being converted for the RAF, and a further nine for civil use. United States military service At the time of its entry into the war, the United States Army Air Service lacked any aircraft suitable for front line combat. It therefore procured various aircraft from the British and French, one being the DH.4. As the DH-4, it was manufactured mostly by Dayton-Wright and Fisher Body for service with the United States from 1918, the first American built DH-4 being delivered to France in May 1918, with combat operations commencing in August 1918. The powerplant was a 400 hp (300 kW) Liberty L-12 and it was fitted with two forward-firing .30 in (7.62 mm) synchronized Marlin-Rockwell M1917 (a development of the Colt-Browning) machine guns in the nose and two .30 in (7.62 mm) Lewis guns in the rear and could carry 322 lb (146 kg) of bombs. it could also be equipped with various radios like the SCR-68 for artillery spotting missions. The heavier engine reduced performance compared with the Rolls-Royce powered version, but as the "Liberty Plane" it became the US Army Air Service standard general purpose two-seater, and on the whole was fairly popular with its crews. Aircrew operating the DH-4 were awarded four of the six Medals of Honor awarded to American aviators. First Lieutenant Harold Ernest Goettler and Second Lieutenant Erwin R. Bleckley received posthumous awards after being killed on 12 October 1918 attempting to drop supplies to the Lost Battalion of the 77th Division, cut off by German troops during the Meuse-Argonne Offensive; while Second Lieutenant Ralph Talbot and Gunnery Sergeant Robert G. Robinson of the United States Marine Corps (USMC) were awarded the Medal of Honor for beating off attacks from 12 German fighters during a bombing raid over Belgium on 8 October 1918. The type flew with 13 U.S. squadrons by the end of 1918. Following the end of the First World War, America had a large surplus of DH-4s, with the improved DH-4B becoming available, although none had been shipped to France. It was therefore decided that there was no point in returning aircraft across the Atlantic, so those remaining in France, together with other obsolete observation and trainer aircraft, were burned in what became known as the "Billion Dollar Bonfire". With limited funds available to develop and purchase replacements, the remaining DH-4s formed a major part of American air strength for several years, used for many roles, with as many as 60 variants produced. DH-4s were also widely used for experimental flying, being used as engine testbeds and fitted with new wings. They were used for the first trials of air-to-air refueling on 27 June 1923, and one carried out an endurance flight of 37 hours, 15 minutes on 27-28 August, being refueled 16 times and setting 16 new world records for distance, speed and duration. The DH-4 remained in service with the United States Army Air Corps, successor to the United States Army Air Service, until 1932. A large number of DH-4s were also used by the United States Navy and United States Marine Corps, both during the First World War and postwar. The Navy and Marine Corps received a total of 51 DH-4s during wartime, followed by 172 DH-4B and DH-4B-1 aircraft postwar and 30 DH-4M-1s with welded steel-tube fuselages (redesignated O2B) in 1925. They remained in service with the Marine Corps until 1929, being used against rebel factions in Nicaragua in 1927, carrying out the first dive-bombing attacks made by U.S. military forces. The U.S. Navy converted some DH-4M-1s into primitive air ambulances that could carry one stretcher casualty in an enclosed area behind the pilot. Civil use Following the end of the First World War, large numbers of DH.4s and DH.4As were used to operate scheduled passenger services in Europe by such airlines as Aircraft Transport and Travel, Handley Page Transport and the Belgium airline SNETA. G-EAJC of Aircraft Transport and Travel flew the first British commercial passenger service from Hounslow Heath Aerodrome to Paris Le Bourget on 25 August 1919, carrying a reporter from the Evening Standard newspaper and a load of newspapers and other freight. They were used by Aircraft Transport and Travel until it shut down in 1920, while Handley Page Transport and SNETA continued operating the DH.4 until 1921. One aircraft was used by Instone Air Lines until its merger into Imperial Airways in 1924. On September 4, 1922, Jimmy Doolittle made the first cross-country flight, flying a de Havilland DH-4 - which was equipped with early navigational instruments - from Pablo Beach (now Jacksonville Beach), Florida, to Rockwell Field, San Diego, California, in 21 hours and 19 minutes, making only one refueling stop at Kelly Field. The DH.4 were also used by the Australian airline QANTAS, flying its first airmail service in 1922. Twelve DH.4s forming part of the Imperial Gift to Canada were used for forestry patrol and survey work, spotting hundreds of forest fires and helping to save millions of dollars worth of timber, with the last example finally being withdrawn in 1927. The U.S. Post Office also adopted the DH-4 to carry air mail. The Service acquired 100 of them from the army in 1918, and retrofitted them to make them safer, denominating them as the DH.4B. In 1919, the DH-4B was standardised by the US Post Office, being modified to be flown from the rear cockpit with a 400 lb (180 kg) watertight mail compartment replacing the forward cockpit. The airmail DH-4B were later modified with revised landing gear and an enlarged rudder. DH-4s were used to establish a coast-to-coast, transcontinental airmail service, between San Francisco and New York, a distance of 2,680 mi (4,310 km), involving night flight, the first services starting on 21 August 1924. The DH-4 continued in Post Office service until 1927, when the last airmail routes were passed to private contractors. War-surplus DH-4s were available cheaply in sufficient quantities to stimulate the development of "utility aviation": surveying, commercial photography, law enforcement, agricultural applications and other practical applications. Variants UK variants DH.4 - Two-seat day bomber biplane. DH.4A - Transport version. Built in the United Kingdom. Two passengers in glazed cabin behind pilot. DH.4R - Single seat racer - 450 hp (340 kW) Napier Lion engine. Soviet variants Copy of DH.4 manufactured by Polikarpov in the former Dux Factory in the 1920s. United States variants DH-4 - Two-seat day bomber biplane, built in the United States. DH-4A - Civil version, built in the United States. DH-4B - Rebuilt version of Liberty powered DH-4 for U.S. Air Service. Pilot's cockpit relocated to behind fuel tank, adjacent to observer's cockpit. DH-4B-1 - Increased fuel capacity (110 US gal (420 L; 92 imp gal)). DH-4B-2 - Trainer version. DH-4B-3 - Fitted with 135 US gal (510 L; 112 imp gal) fuel tank. DH-4B-4 - Civil version. DH-4B-5 - Experimental civil conversion with enclosed cabin. DH-4BD - Cropdusting version of DH-4B. DH-4BG - Fitted with smokescreen generators. DH-4BK - Night flying version. DH-4BM - Single seat version for communications. DH-4BM-1 - Dual control version of BM. DH-4BM-2 - Dual control version of BM. DH-4-BP - Experimental photo reconnaissance version. DH-4-BP-1 - BP converted for survey work. DH-4BS - Testbed for supercharged Liberty. DH-4BT - Dual control trainer. DH-4BW - Testbed for Wright H engine. DH-4C - 300 hp (220 kW) Packard engine. DH-4L - Civil version. DH-4M - Rebuilt version of DH-4 with steel tube fuselage. DH-4Amb - Ambulance. DH-4M-1 - Postwar version by Boeing (Model 16) with new fuselage, designated O2B-1 by Navy. DH-4M-1T - Dual control trainer conversion of DH-4M. DH-4M-1K - Target tug conversion. O2B-2 - Cross-country and night flying conversion for Navy. DH-4M-2 - Postwar version by Atlantic. L.W.F. J-2 - Twin-engine long range development of DH-4 (also known as Twin DH), powered by two 200 hp (150 kW) Hall-Scott-Liberty L-6 engines and with wingspan of 52 ft 6 in (16.00 m); 20 built for U.S. Post Office, 10 for U.S. Army. XCO-7 (Boeing Model 42) - Two-seat observation version with Boeing designed wings, enlarged tailplane and divided landing gear. XCO-8 - Was a designation of one Atlantic DH.4M-2 fitted with Loening COA-1 wings and powered by a Liberty 12A engine. Operators Civil operators Argentina The River Plate Aviation Co. Ltd. Australia QANTAS Belgium SNETA United Kingdom Aircraft Transport and Travel Limited Handley Page Transport Imperial Airways Instone Air Line United States U.S. Post Office Military operators Belgium Aviation Militaire Belge Canada Canadian Air Force (1918-1920) Royal Canadian Air Force Chile Chilean Air Force Cuba Cuban Air Force (American built DH-4s.) Greece Hellenic Air Force Hellenic Navy Iran Imperial Iranian Air Force Mexico Fuerza Aérea Mexicana Nicaragua Nicaraguan Air Force (The Nicaragua Air Force received seven DH-4Bs.) New Zealand (The New Zealand Permanent Air Force operated two aircraft from 1919 to 1929. It was used by the NZPAF as an advanced training aircraft. The DH.4 has the distinction of being the first aircraft to fly over Mount Cook on 8 September 1920. It also set a New Zealand altitude record of 21,000 ft (6,400 m) on 27 November 1919.) South Africa South African Air Force Soviet Union Soviet Air Force Kingdom of Spain Spanish Air Force Turkey Turkish Air Force United Kingdom Royal Flying Corps Royal Air Force Royal Naval Air Service United States 1. United States Army Air Service - 8th Aero Squadron - 11th Aero Squadron - 20th Aero Squadron - 50th Aero Squadron - 85th Aero Squadron - 91st Aero Squadron - 104th Aero Squadron - 135th Aero Squadron - 163rd Aero Squadron - 166th Aero Squadron - 168th Aero Squadron - 278th Aero Squadron - 354th Aero Squadron 2. United States Navy 3. United States Marine Corps Surviving aircraft 21959 - The prototype American-built DH-4 is on display at the National Air and Space Museum in Washington D.C. Unknown ID - A DH-4B is on display in the main atrium of the National Postal Museum in Washington, D.C. Unknown ID - A DH-4 is on display at the National Museum of the Marine Corps in Triangle, Virginia. It was restored by Century Aviation. Unknown ID - A DH-4B at the Pearson Air Museum in Vancouver, Washington. It was restored by Century Aviation. Unknown ID - A DH-4B is on display at the National Museum of the United States Air Force in Dayton, Ohio. It was restored by Century Aviation. Unknown ID - A DH-4B is on display at Fantasy of Flight in Polk City, Florida. It was restored by Century Aviation. Unknown ID - A DH-4B is under restoration by Century Aviation for Fantasy of Flight in Polk City, Florida. It will be powered by a rebuilt Liberty V-12. Unknown ID - A DH-4M-1 is on display at the Evergreen Aviation and Space Museum in McMinnville, Oregon. This aircraft was previously owned by Paul Mantz. Unknown ID - A DH-4M-2A is airworthy at the Historic Aircraft Restoration Museum in Maryland Heights, Missouri. Unknown ID - A DH-4 is on display at the Omaka Aviation Heritage Centre in Blenheim, New Zealand. This aircraft was previously on display at the Crawford Auto-Aviation Museum in Cleveland, Ohio and was at one point loaned to the United States Air Force Museum. Replica - A DH-4 is on display at the Museo del Aire in Madrid, Spain. Replica - A DH.4 is airworthy with The Vintage Aviator Limited in Masterton, New Zealand. It was built by Century Aviation and is powered by a rebuilt Liberty V-12. Specifications (DH.4 - Eagle VIII engine) (Data from The British Bomber since 1914, The de Havilland DH.4) General characteristics Crew: 2 Length: 30 ft 8 in (9.35 m) Wingspan: 43 ft 4 in (13.21 m) Height: 11 ft 0 in (3.35 m) Wing area: 434 sq ft (40.3 m2) Empty weight: 2,387 lb (1,083 kg) Gross weight: 3,472 lb (1,575 kg) Powerplant: 1 × Rolls-Royce Eagle VIII water-cooled V12 engine, 375 hp (280 kW) (230 hp (170 kW) for BHP Puma) Performance Maximum speed: 143 mph (230 km/h, 124 kn) at sea level (106 mph (171 km/h) for Puma engine variants) Endurance: 3 hr 45 min Service ceiling: 22,000 ft (6,700 m) Time to altitude: 9 min to 10,000 ft (3,000 m) Armament Guns: One fixed forward-firing .303 in (7.7 mm) Vickers machine gun, 1 or 2 .303 in (7.7 mm) Lewis guns on a Scarff ring Bombs: 460 lb (210 kg) of bombs Related development Airco DH.9 Airco DH.9A DH.4 above the clouds in France An early production DH.4 Friends of Jenny DH.4, 2018 Strength tests on various DH-4 wing ribs during World War I A formation of DH-4s in flight Robertson Aircraft Corp. operated DH-4 mailplane (CAM 2) 1926 at the Historic Aircraft Restoration Museum In 1923 the U.S. Post Office released a stamp featuring the DeHavilland Biplane being used for airmail service Canadian DH-4 G-CYDK in the 1920s Wright Radial Engine (R-1) fitted to a De Havilland DH-4B airframe The DH-4B on display at the National Museum of the United States Air Force Airco DH.5 Airco DH.5 Role - fighter Manufacturer - Aircraft Manufacturing Company (Airco) Designer - Geoffrey de Havilland First flight - August 1916 Introduction - May 1917 Primary user - Royal Flying Corps (RFC) Number built - 550 The Airco DH.5 was a British First World War single-seat biplane fighter aircraft. It was designed and manufactured at British aviation company Airco. Development was led by aircraft designer Geoffrey de Havilland as a replacement for the obsolete Airco DH.2. The DH.5 was one of the first British fighters designed with the improved Constantinesco gun synchronizer, which allowed a forward-firing machine gun to fire through the propeller faster and more reliably than the older mechanical systems. It was also one of the earliest biplanes with a marked "back-stagger" of its wings. By the time the DH.5 was fielded, it was already inferior to other fighters in service and thus both unpopular and unsatisfactory with the pilots of the Royal Flying Corps (RFC). The type was quickly withdrawn from service once supplies of the Royal Aircraft Factory S.E.5 permitted. Design and development Origins Shortly after completing work upon the twin-seat Airco DH.4 light bomber, Captain Geoffrey de Havilland commenced work on a new single-seat fighter aircraft to replace the obsolete Airco DH.2 fighter, which was designated at the DH.5. The design sought to combine the superior performance of a tractor biplane with the excellent forward visibility of a pusher type. The resultant aircraft was a relatively compact single-bay biplane, and while the construction was that of a conventional tractor biplane, the mainplanes were given 27 in (690 mm) of backward stagger, so that the lower wing was forward of the upper wing. This configuration enabled the pilot to be positioned underneath the leading edge of the wing, providing uninterrupted forward and upward views, a configuration that has been described as radical, for the era. The first prototype underwent manufacturer's trials at Hendon Aerodrome in late 1916. It was powered by a single 110 hp (82 kW) Le Rhône 9Ja rotary engine, which drove a two-blade propeller. The fuselage had flat sides aft of the wings and featured short fairings either side of the circular engine cowling. Towards the rear of the airframe, the fuselage tapered to a vertical rudder post at the tail, which comprised a small fin and horn-balanced rudder arrangement. The equal-span single-bay wings were outfitted with large ailerons on both the upper and lower mainplanes, while a rubber bungee cord attached to the upper ailerons returned them to their standard position. At an early stage, the prototype was fitted with a small hemispherical spinner. As the pilot was seated forward of the centre of gravity, the main fuel tank was behind the cockpit, below the oil tank. An auxiliary gravity fuel tank was fitted over the top mainplane, offset to the right. Into flight Test flights determined that it lacked sufficient directional control, which led to an enlarged fin and rudder being adopted. Early on, the first prototype had been flown unarmed. Around the same time as the revised tail unit was installed, it was also armed in preparation for official trials. The prototype armament installation comprised a single forward-firing .303 in (7.7 mm) Vickers machine gun, which was either fixed to fire upward at an angle or possibly mounted so that its elevation could be adjusted in flight. In the production installation the gun was given a more conventional fixed mounting on top of the cowl, offset to the left, to fire in the line of flight. The DH.5 may have been designed with the intention of attacking enemy planes from below, but its limited operational ceiling in comparison to contemporaries would have made this infeasible. On 9 December 1916, the DH.5 prototype commenced service trials at the Central Flying School. The official report from the observations of its pilots was largely favourable, stating that it possessed satisfactory stability and controllability, its favourable qualities for reconnaissance and agility, but also noted a poor view to the rear. The type's speed was a significant advance over its DH.2 predecessor, but existing fighters already exceeded its capabilities, especially in climb. Performance may have been reduced by an alternative four-bladed propeller fitted during testing. Production By the time trials commenced in France, significantly more capable types such as the Sopwith Camel and the Royal Aircraft Factory S.E.5 were not far behind. The performance of the new fighter was also inferior to the earlier Sopwith Pup. The provision of a single machine gun at a time when most fighters carried two also meant the aircraft was under-armed for 1917. Nevertheless, on 15 January 1917, the DH.5 was ordered into production with two initial contracts for a total of 400 aircraft. A total of four manufacturers were involved in producing the type: Airco (200), British Caudron (50), Darracq (200) and March, Jones & Cribb (100). The DH.5 was subject to extensive changes prior to entering mass production. A substitute fuel system was adopted, which included an additional five-gallon gravity tank mounted above the upper wing and a pressurised main tank directly behind the pilot's seat. The appearance of the aircraft was drastically changed via a revised fuselage, which now had an octagonal cross section and featured additional stringers around the area of the engine cowling. The horn balance was removed from the rudder. Some of these changes made the aircraft more complex to manufacture. The main fuselage was produced in two sections that were butt-joined at an attachment point aligned with the rear wing struts. Extensive use was made of plywood throughput the structure, while the remainder used conventional wire-braced wooden box-girders. While some DH.5s were built with the original rubber bungee return springs on the ailerons, later-built examples used pulleys and balance cables. A positive feature of the aircraft was its great structural strength, which was revealed during April 1917 in destructive testing. Operational history The introduction of the DH.5 to squadron service with the Royal Flying Corps (RFC) was protracted. These delays were the result of Airco's focus on the more successful DH.4, greatly hindered the type's prospects. The first DH.5 only arrived with No. 24 Squadron on 1 May 1917, and deliveries were slow, so that the squadron only had a few by 7 June. The DH.5 was not well regarded by the squadron, a common feeling with other users. Soon after entering service, the DH.5 quickly proved to be most unpopular with the RFC. Its unconventional appearance led to largely unfounded rumours of handling difficulties. There were also claims that the DH.5 had gone into service against the wishes of its designers. What was true was that while it was manoeuvrable, performance rapidly dropped off over 10,000 ft (3,000 m), and it lost altitude quickly in combat. The position of the upper wing resulted in an unfortunate blind spot above and to the rear which was the very direction from which a single-seater would generally be attacked from. The robust construction, good performance at low altitude and the pilot's good forward field of view made the aircraft a useful ground-attack aircraft. In this capacity, the type served with distinction in the Battle of Cambrai. During the battle, the DH.5 had, in conjunction with Sopwith Camels, provided airborne mobile machine gun coverage to the infantry, strafing German trenches and causing heavy losses to the Germans. Replacement had already begun and Cambrai had little impact on its withdrawal. The DH.5 formed the initial equipment of No. 2 Squadron Australian Flying Corps, the first Australian fighter squadron. It was unsatisfactory and enemy twin-seater airplanes were often able to escape. It served mainly as a ground-attack aircraft until December 1917, when the type was replaced by the S.E.5a. By this time, the withdrawal of the type from the Western Front was almost complete, the last DH.5 squadron receiving the S.E.5a in January 1918. DH.5s issued to training units proved unpopular and the type soon vanished from RFC service. A number of retired aircraft were reused as trials machines, some of these tests included alternative gun mountings, jettisonable fuel tanks and plywood coverings. No original aircraft has survived but an airworthy full-scale reproduction, built in the United States by John Shiveley, is on display in the Aviation Heritage Centre, Omaka Aerodrome, New Zealand. Military operators Australia - Australian Flying Corps No. 2 Squadron AFC (a.k.a. No. 68 Squadron RFC) in France No. 6 (Training) Squadron AFC No. 7 (Training) Squadron AFC in the United Kingdom United Kingdom - Royal Flying Corps No. 24 Squadron RFC No. 32 Squadron RFC No. 41 Squadron RFC No. 64 Squadron RFC No. 68 Squadron RFC Specifications (Data from British Aeroplanes 1914-18) General characteristics Crew: One Length: 22 ft 0 in (6.71 m) Wingspan: 25 ft 8 in (7.82 m) Height: 9 ft 1+1⁄2 in (2.781 m) Wing area: 212.1 sq ft (19.70 m2) Empty weight: 1,010 lb (458 kg) Gross weight: 1,492 lb (677 kg) Fuel capacity: 26 imp gal (31 US gal; 120 L) Powerplant: 1 × Le Rhône 9J nine-cylinder rotary engine, 110 hp (82 kW) Propellers: 2-bladed wood fixed pitch propeller, 8 ft 6 in (2.59 m) diameter Performance Maximum speed: 102 mph (164 km/h, 89 kn) at 10,000 ft (3,000 m) Endurance: 2 hr 45 min Service ceiling: 16,000 ft (4,900 m) Time to altitude: ** 12 min 25 s to 10,000 ft (3,000 m) . 27 min 30 s to 15,000 ft (4,600 m) Armament Guns: 1 × 0.303 in (7.7 mm) Vickers machine gun Bombs: racks for four 25 lb (11 kg) bombs under fuselage Aircraft of comparable role, configuration, and era Sopwith Dolphin DH.5 with the Australian Flying Corps in September 1917 Replica DH.5 ZK-JOQ at the Classic Fighters 2015 airshow in Blenheim, New Zealand Airco DH.6 DH.6 Role - Trainer National origin - United Kingdom Manufacturer - Airco Designer - Geoffrey de Havilland First flight - 1916 Status - retired Primary users - Royal Flying Corps Royal Air Force Number built - over 2,280 The Airco DH.6 was a British military trainer biplane used by the Royal Flying Corps during the First World War. Known by various nicknames, including the "Clutching hand" and "Skyhook", many survived to be used as a civil light aircraft in the postwar era. Design and development The DH.6 was specifically designed as a military trainer, at a time when it was usual for obsolete service types to be used in this role. Geoffrey de Havilland seems to have had two design criteria in mind. The first was that it should be inexpensive and easy to build, and above all, simple to repair after the mishaps common in training units. The top and bottom wings were square-cut and interchangeable, hence roundels often located in unusual positions. They were heavily cambered, and braced with cables rather than streamlined wires. On the original version of the type there was no stagger. Even the fin and rudder, on the prototype of the usual curved de Havilland outline, were cut square on production machines. The fuselage structure was a straight box with no attempt at refinement of outline - instructor and pupil sat in tandem on basketwork seats in a single cockpit, spartan even by the standards of the time. The standard engine was the readily available 90 hp (67 kW) RAF 1a. Because of its use in the B.E.2 the engine was familiar to RFC mechanics. No cowling was used, and upswept straight exhaust pipes were fitted. When stocks of the RAF 1a ran short, other engines were fitted, including the 80 hp (60 kW) Renault. The second design criterion was that the new trainer should be relatively safe to fly, both for the student and his instructor. RFC instructors at the time referred to student pilots as "Huns" (the term normally applied to German airmen) and casualties at training schools were high. To improve safety the instructor could decouple the student's controls to avoid having to wrestle with him. The new trainer's flying characteristics were selected to achieve the desired safety. De Havilland had carried out extensive research into stability and control in aircraft while with the Royal Aircraft Factory, which helped in designing a safe but deliberately unstable aircraft. As a result, the DH.6 had very gentle flying characteristics and was probably the most "forgiving" aircraft of its time, allowing itself to be flown "crab wise" in improperly banked turns and able to maintain sustained flight at speeds as low as 30 miles per hour (48 km/h). In fact, the DH.6 was described as "too safe" to make a good trainer, as its reaction to inexpert piloting was too gentle to prepare pilots for combat aircraft such as the Sopwith Camel, whose handling was unusually difficult even for the era. With its low power, strong construction and lack of streamlining, its maximum speed was very low. Wartime production At least 2,282 DH.6s were built in the UK during the war, out of orders of about 3,000. Besides Airco, batches were built by Grahame-White, Kingsbury Aviation, Harland and Wolff, Morgan, Savages, Ransomes, Sims & Jefferies, and Gloucestershire. A single DH.6 was constructed in July 1917 by Canadian Aeroplanes Ltd. as a prototype for projected production, should supply of the Curtiss JN-4 (Can) prove inadequate, and it was the first British-designed aircraft built in Canada. In the event, the expected shortage of "Canucks" never materialized and only one example was built. Operational history In 1917, training of RFC pilots began to receive a long overdue overhaul. The School of Special Flying at Gosport in Hampshire was established by Maj. Robert R. Smith-Barry with the aim of making flight instructors into specially trained experts - rather than entrusting the role to novices who had barely completed their own training, and operational pilots being "rested" to recover from combat fatigue. The Avro 504K was adopted as the standard trainer by the end of 1917, with the DH.6 becoming surplus as far as training was concerned. At the end of 1917, about 300 DH.6s were transferred to the RNAS for anti-submarine patrols. While far from ideal for this work, the type proved surprisingly "seaworthy", being known to float for as long as ten hours after ditching. On operations, the underpowered trainer could not carry both an observer and weaponry. The majority of patrols were flown solo, allowing a token bomb load and a lightweight radio installation to be carried, although convoy escort missions generally carried an observer who could communicate with ships using an Aldis lamp. The "built in" instability designed to keep a student pilot alert proved tiring for pilots on long patrols over water, and experimental changes were made in mid-1918 to improve stability. These included the introduction of 10 in (25 cm) of back-stagger to wings of reduced chord and camber, with narrower elevators and rudder. DH.6s modified to this standard were unofficially dubbed "DH 6As". 1050 DH.6s were still on charge with the RAF on 31 October 1918. Nicknames Many RFC/RAF aircraft of this period received nicknames (some of which, like the "zoo" names of Sopwith types, reached semi-official status), and the DH.6 has a variety of humorous but disrespectful epithets. The reactions of novice pilots were probably behind it being called the "clutching hand". Australian airmen may have been referring to its lack of speed when calling it "skyhook", although the shape of the exhaust pipes has also been mentioned. Other nicknames for the type included "crab," "clockwork mouse," "flying coffin" and "dung hunter" (these last two on account of the shape of the plywood cockpit, thought to resemble either a coffin or an outside toilet). Postwar and civil use There was no place for the DH.6 in the postwar RAF, and survivors were sold off as surplus. In 1919, many went to civilian operators - especially for "joy riding". Some were exported to South Africa and the Point Cook-based aircraft were sold in Australia, where they continued flying into the late 1930s. One example was exported to New Zealand for use by the Walsh brothers’ New Zealand Flying School and first flew there in February 1920, however it was damaged by a gale in August the same year and was never repaired. Some 60 aircraft were licence-built in Spain from 1921 onwards with Hispano-Suiza 8 engines, refined fuselages that included separate cockpits, and rounded "de Havilland style" rudder/fin assemblies. At least some of these found their way into the inventory of two Spanish Air Force training establishments. A DH.6 became the first powered aircraft to be owned by a British Scout Troop, when it was presented to 3rd Hampden (Middlesex) Scouts in 1921. Variants DH.6 Two-seat training aircraft. DH.6A Modified to improve stability for patrol duties. Operators - Australia 1. Australian Flying Corps No. 5 (Training) Squadron AFC in the United Kingdom No. 7 (Training) Squadron AFC in the United Kingdom Central Flying School AFC at Point Cook, Victoria - Greece 1. Hellenic Naval Air Service - New Zealand 1. New Zealand Flying School - Spain 1. Spanish Air Force - United Kingdom 1. Royal Flying Corps / Royal Air Force No. 67 Squadron RAF No. 99 Squadron RAF No. 105 Squadron RAF No. 110 Squadron RAF No. 144 Squadron RAF No. 187 Squadron RAF No. 190 Squadron RAF No. 236 Squadron RAF No. 244 Squadron RAF No. 250 Squadron RAF No. 251 Squadron RAF No. 252 Squadron RAF No. 253 Squadron RAF No. 254 Squadron RAF No. 255 Squadron RAF No. 256 Squadron RAF No. 258 Squadron RAF No. 260 Squadron RAF No. 272 Squadron RAF No. 274 Squadron RAF 2. Royal Naval Air Service Specifications (DH.6) (Data from De Havilland Aircraft since 1909) General characteristics Crew: As trainer: two, pilot and instructor As patrol aircraft: one As postwar joy riding aircraft: up to three, pilot plus one or two passengers Length: 27 ft 3+1⁄2 in (8.319 m) Wingspan: 35 ft 11 in (10.95 m) Height: 10 ft 9+1⁄2 in (3.289 m) Wing area: 436.25 sq ft (40.529 m2) Empty weight: 1,460 lb (662 kg) Gross weight: 2,030 lb (921 kg) Fuel capacity: 25 imp gal (30 US gal; 110 L) Powerplant: 1 × RAF 1a air-cooled V8 engine, 90 hp (67 kW) Propellers: 2-bladed wood fixed pitch propeller Performance Maximum speed: 70 mph (110 km/h, 61 kn) Stall speed: 40 mph (64 km/h, 35 kn) Endurance: 2 hr 45 min Rate of climb: 225 ft/min (1.14 m/s) Armament Bombs: 1 × 100 lb (45 kg) bomb or similar load of smaller bombs could be carried on anti-submarine patrol Airco DH.9 DH.9 Role - Bomber Manufacturer - Airco Designer - Geoffrey de Havilland First flight - July 1917 Introduction - November 1917 Retired - 1937 Primary users - Royal Air Force / Royal Flying Corps / Royal Naval Air Service / South African Air Force Number built - 4,091 Variants - Airco DH.9A / Airco DH.9C / Westland Walrus The Airco DH.9 (from de Havilland 9) - also known after 1920 as the de Havilland DH.9 - is a British single-engined biplane bomber that was developed and deployed during the First World War. The DH.9 was a development of Airco's earlier successful DH.4, with which it shared many components. These were mated to an all-new fuselage and the 230 hp BHP engine, which promised increased performance. Anticipating its usefulness, the type was ordered in very large numbers for Britain's Royal Flying Corps (RFC). Upon entering service, the DH.9's performance was found to be unsatisfactory. The BHP engine was unreliable and failed to provide the expected power, which gave the DH.9 poorer performance than the aircraft it had been meant to replace. The performance deficit was blamed for the heavy losses they suffered over the Western Front. The redesigned DH.9A was fitted with a more powerful and reliable American Liberty L-12 engine which rectified the shortcomings of the original DH.9 model. Development Origins During June 1917, partially as a result of attacks by German bombers on London, the War Office issued its recommendation to almost double the size of the Royal Flying Corps (RFC) to a total of 200 squadrons. In early July 1917, the British Cabinet accepted the recommendation, with the intention that the majority of the new squadrons planned to be equipped with bombers. While an order for 700 DH.4s was placed on 28 June 1917, on 23 July 1917, the Air Board were presented with drawings for a modified DH.4 that delivering greater range under a new type number, DH.9. The DH.9 was designed by de Havilland for the Aircraft Manufacturing Company in 1916 as a successor to the DH.4. It used the wings and tail unit of the DH.4 but featured a modified fuselage which moved the pilot closer to the gunner/observer and away from the engine and fuel tank, which facilitated communication and was a more optimal fighting configuration. The other major change from the DH.4 was the choice of the promising new B.H.P engine, which was predicted to produce 300 hp (220 kW) to provide adequate performance to match enemy fighters. Based on the performance estimates for the DH.9 (which were initially expected to surpass those of the DH.4), and the similarity to the DH.4, which meant that it would be easy to convert production over to the new aircraft, it was decided to place a massive number of orders (totalling 4,630 aircraft) for the type prior to the aircraft even flying for the first time. Existing contracts originally placed for the DH.4 were also converted to the DH.9. The Air Board had been specifically assured that there would be an initial production delay of no more than a month. According to aviation author J.M Bruce, the selection of the DH.9 "seems to have been taken in a spirit of optimism or blind faith, for its chosen engine was, in July 1917, experiencing serious manufacturing difficulties". Into flight In July 1917, the prototype (a converted DH.4) performed its maiden flight from Hendon Aerodrome, Colindale, London. Trials of the type were extensive, including a number of tests performed at RAF Martlesham Heath. Unfortunately, the BHP engine proved unable to reliably deliver its expected power; the engine having been de-rated to 230 hp (170 kW) in order to improve its reliability. This deficit had a drastic effect on the aircraft's performance, especially at high altitude, with it being inferior to that of the DH.4 it was supposed to replace. The poor performance of the aircraft meant that the DH.9 would have to fight its way through enemy fighters, which could easily catch the DH.9 where the DH.4 could avoid many of these attacks. As early as November 1917, some officials, such as General Hugh Trenchard, raised repeated objections to the aircraft based upon its disappointing performance; however, in his response, President of the Air Council Sir William Weir started that "it was the choice of having the DH.9 with the B.H.P. engine, or of having nothing at all. Additionally, by this point, production of the DH.9 was already well underway. BHP engines were produced by Siddeley-Deasy (developed as the Puma) and Galloway Engineering (developed as the Adriatic). In British military service both Siddeley and Galloway built engines were known as the 230 hp BHP although they had different dimensions and few interchangeable parts. The vast majority of BHP engines in service were built by Siddeley-Deasy. Multiple attempts were made to provide the DH.9 with a better engine. In August 1917, an order for 2,000 Fiat A12 engines was placed, intending to be delivered between January and June 1918 and used upon some production batches of the D.H9; however, deliveries of the Fiat engine were unsatisfactory. Another alternative powerplant was adopted in the form of the 430 hp (320 kW) Napier Lion engine; one such Lion-engined aircraft achieved a World Altitude Record of 30,500 ft (9,300 m) on 2 January 1919. However, none of these options were deemed to be entirely satisfactory, it required being redesigned into the DH.9A, for which an American V-12 Liberty engine was adopted, to transform the aircraft. According to Bruce, aside from the engine issue: "Certainly, there was little wrong with the aircraft itself.". Design The Airco DH.9 was a single-engine British bomber aircraft, sharing a high level of similarities with the preceding DH.4. The standard flight surfaces were broadly the same, but adopted a highly redesigned fuselage configuration, including the repositioning of the pilot's cockpit to a more rearwards position. Structurally, the fuselage was similar to its predecessor; plywood cladding covered the forward fuselage, which had no internal bracing, while a conventional wire-braced box girder structure was used aft of the cockpits. Internal stowage for a pair of 230 lb (100 kg) or four 112 lb (51 kg) bombs was provided for, although little use of this capability was made operationally. While the DH.9 was deemed to be suitable for daytime bombing operations, it was found to be incapable of effective nighttime bombing due to the pilot's view being obstructed and visibility via the bombsight being unsuitable. The revised cockpit positioning of the DH.9 from the DH.4 placed the pilot and the observer closer together, which was viewed by the RAF as being a considerable advantage in aerial combat; however, the pilot's visibility for ground reconnaissance was decreased as a result. Both radio sets and cameras could be installed. The fuel tanks were enclosed in doped fabric, intended to drain fuel away if the tanks were hit by enemy fire. According to the testing squadron, the DH.9 possessed a high level of manoeuvrability, was relatively easy to perform landings aside from a poor view during the approach. Various improvements and supplementary equipment were trialled and occasionally adopted. Tests of various engines, radiators, silencers and parachutes were conducted to evaluate their performance, however, few of these improvements were ultimately adopted. During the war, numerous customisations and improvised improvements were made to the aircraft by the maintenance crews of individual squadrons, often for the purpose of addressing the type's engine performance issues. After the end of the war, many DH.9s, which had been originally delivered as bombers, were sold; these were often reconfigured to serve in different roles, including passenger and cargo transport, trainer aircraft, and as air ambulances. Operational history First World War service To boost the rate of production, quantity orders for the DH.9 were also placed with Alliance, G & J.Weir, Short Brothers, Vulcan, Waring & Gillow and National Aircraft Factories No. 1 and No. 2. The first deliveries of the type occurred during November 1917 to 108 Squadron RFC; by the end of 1917, a total of five DH.9s had been delivered and passed their final inspections. The first combat engagement of the type, performed over France, was performed in March 1918 by No. 6 Squadron RNAS. By July 1918, a total of nine operational squadrons deployed to the Western Front were using the type. The DH.9's performance in action over the Western Front was typically deemed to have been a disaster; heavy losses of the type were quickly incurred, attributed to both its poor performance and to engine failures, despite the prior derating of its engine to reduce the failure rate. Between May and November 1918, a pair of squadrons stationed at the Western Front (Nos. 99 and 104) had 54 of its DH.9s shot down and another 94 aircraft written off due to accidents. On multiple occasions, less than half of a flight of bombers would reach their intended targets; according to Bruce, the successful missions performed by the DH.9 were frequently a product of "the courage and determination of the pilots and observers that flew them". Squadrons would often implement their own home-built enhancements to their aircraft, such as enlarged carburetor air intakes and modified fuel mixture controls. Nevertheless, the type proved capable during some engagements; on 23 August 1918, a DH.9 flown by Lieutenant Arthur Rowe Spurling of 49 Squadron, with his observer, Sergeant Frank Bell, single-handedly attacked thirty Fokker D.VII fighters, downing five of them. On 9 August 1918, Lieutenant E.A. Simpson of 49 Squadron, while flying a bombing mission upon bridges at Falvy and Bethencourt, shot down four hostile fighters while defending against repeated attacks upon the formation. In another instance, Captain John Stevenson Stubbs achieved 11 aerial victories in a DH.9, including the highly unusual feat of balloon busting while flying the type. Despite its general lack of performance, due to its large numbers, the DH.9 was introduced to nearly every theatre of the conflict prior to the signing of the Armistice of 11 November 1918, which ended the conflict. Reportedly, the DH.9 was also more successful in combat against the Turkish forces in the Middle East, where they faced less aerial opposition. Stationed at coastal aerodromes across the British mainland, the type was also used extensively to perform coastal patrol missions with the aim of deterring the operations of enemy U-boats. Post war service Following the end of the First World War, a number of DH.9s operated by 47 Squadron and 221 Squadron were sent to southern Russia in 1919 in support of the White Russian Army of General Denikin, participating in the Russian Civil War. In this theatre, the aircraft were often operating within challenging conditions. The last combat use of the DH.9 by the RAF was in support of the final campaign against Diiriye Guure in Somalia during January-February 1920. Amongst those aircraft used in Somalia, one DH.9 was modified to function as an air ambulance, being able to load and transport a single stretcher case, which was carried upon the upper longerons directly to the rear of the pilot's cockpit. Further ambulance conversions were performed, including a number that were operated by the Royal Netherlands Air Force. Surprisingly, production was allowed to continue after the end of the war into 1919. In 1920, the DH.9 was finally withdrawn from service by the RAF. In addition to British manufacturing, several other countries had commenced production of the type; perhaps the most significant of these was the Airco DH.9A, which was fitted with the American V-12 Liberty engine, and was produced in the thousands even though production was curtailed by the signing of the Armistice that had ended the First World War. Belgium and Spain also produced the type, the latter producing hundreds of the type equipped with a 300 hp (220 kW) Hispano-Suiza engine; some of these were still in service in 1940. Following the end of the conflict, large numbers of surplus DH.9s became available at low prices and the type was widely exported; this included those aircraft that were donated to the Dominions as well as India as part of the Imperial Gift programme. The South African Air Force (SAAF) received a total of 48 DH.9s, and used them extensively, including against the Rand Revolt in 1922. Several South African aircraft were later re-engined with Bristol Jupiter radial engines as the M′pala; such modified aircraft continued to serve until 1937. Possibly the last battle use by any user was in late 1922, during the Turkish War of Independence. Greeks had deployed a number of them against the Kemalists who were fighting the British supported Greek Army invading the remaining chunk of the Ottoman Empire after the 1918 Armistice of Mudros followed by the Sevres Treaty which was rejected by the nationalists. One of Greek DH.9s had made a forced landing behind Turkish lines near Muğla during the Battle of Sakarya previous year, sometime in July 1921. This machine was quickly repaired and was flown to Ankara in August 1921 by famous pilot Vecihi Hürkuş. It was named "Ismet". It was deployed, as the only Turkish airplane at the time, in the last phases of the Battle of Sakarya, making a total of 23 sorties, mostly by Vecihi. Same airplane continued to serve for the remaining of the War of Independence through 1922. There were three more Greek DH.9s found in excellent condition, with plenty of spare parts, near İzmir after the Greek army pulled out hurriedly, having been routed by Kemalists in August 1922. These four planes served the young Turkish Air Force until 1925. Civilian service After the end of the war, large numbers of surplus DH.9s became available, having been deemed to be surplus to requirements by their original military operators; accordingly, many were resold onto civil operators, such as by early aerial transport companies. Large numbers were modified to better perform as transport aircraft, such as the cabin being suitably adapted for the carriage of passengers. In this role, the DH.9 provided a useful load carrying capability and was relatively inexpensive to procure. Accordingly, in various configurations, the type saw prolific use by civil operators. Early air services between London, Paris and Amsterdam were operated by a fleet of DH.9s owned by Aircraft Transport and Travel. A number of DH9s were converted into floatplanes and saw use in India, Bolivia and Rhodesia. Several aircraft were reconfigured to serve as trainer aircraft, being refitted with Armstrong Siddeley Jaguar engines and rubber undercarriages; designated as DH.9Js, the last of these were withdrawn and scrapped in 1936. A number of different DH.9 conversion programmes for civil use were carried out, both by Airco and its successor, the de Havilland Aircraft Company, and by other third party companies, such as the Aircraft Disposal Company. Some radial powered DH.9Js continued in civil use until 1936. One Dh.9 was transported to Japan during the Sempill Mission. A large number of Dh.9s were also apparently exported to China according to the Aircraft Disposal Company. Variants DH.9 - Revised version of the DH.4 with the pilot and observer/gunner placed closer together (3,024 production aircraft built with others built in Belgium and Spain). DH.9A - (also referred to as the Nine-Ack) was designed for Airco by Westland Aircraft to take advantage of the 400 hp (300 kW) American Liberty L-12 engine. Apart from the new engine and slightly larger wings it was identical to the DH.9. Initially it was hoped to quickly replace the DH.9 with the new version, but the shortage of Liberty engines available to the RAF limited the new type's service in the First World War, and it is best known as a standard type in the postwar RAF, serving as a general purpose aircraft for several years. 2,300 DH.9As were built by ten different British companies. DH.9B - Conversions for civilian use as three-seaters (one pilot and two passengers). DH.9C - Conversions for civilian use as four-seaters (one pilot and three passengers). DH.9J - Modernised and re-engined conversions using the 385 hp (287 kW) Armstrong Siddeley Jaguar III radial engine. Used by the De Havilland School of Flying. DH.9J M'pala I - Re-engined conversions carried out by the South African Air Force. Powered by a 450 hp (340 kW) Bristol Jupiter VI radial piston engine. M'pala II - Re-engined conversions carried out by the South African Air Force, powered by a 480 hp (360 kW) Bristol Jupiter VIII radial piston engine. Mantis - Re-engined conversions carried out by the South African Air Force, powered by a 200 hp (150 kW) Wolseley Viper piston engine. Handley Page HP.17 - A DH.9 experimentally fitted with slotted wings, tested 1920-1. USD-9/9A - DH.9s manufactured in the United States by the US Army's Engineering Division and Dayton-Wright. (1,415 ordered, only four built) Operators Military operators Afghanistan Afghan Air Force - 18 aircraft, including 16 built by Duks Aircraft Works, acquired from 1924. Australia Royal Australian Air Force - One used by the RAAF from 1920 to 1929. No. 1 Flying Training School RAAF Belgium Belgian Air Force - 18 aircraft. Canada Canadian Air Force Bolivia Bolivian Air Force Chile Chilean Air Force - Received 20. Estonia Estonian Air Force - Operated 13 from 1919 to 1933. India (Part of Imperial Gift) Greece Royal Hellenic Naval Air Service Kingdom of Hejaz Hejaz Air Force - The Kingdom of Hejaz received 9 DH.9s and 2 DH.9Cs between 1921 and 1924. Five remained in existence (although not airworthy) in 1932. Ireland Irish Air Service Irish Air Corps Latvia Latvian Air Force Netherlands Royal Netherlands East Indies Army Air Force - Operated 36, some of which were re-engined with Pratt & Whitney Wasp radial engine withdrawn in 1934. New Zealand Royal New Zealand Air Force - Three Airco DH.9s in service with the New Zealand Permanent Air Force from 1923 to 1929 as advanced training aircraft. Paraguay Paraguayan Air Force Peru Peruvian Air Force Poland Polish Air Force - 20 received in 1920, used during the Polish-Soviet war, until 1929. Romania Royal Romanian Air Force Spain Kingdom of Spain Spanish Air Force South Africa South African Air Force - Part of the Imperial Gift. Some locally modified with Jupiter engines and named Mpala. Soviet Union Soviet Air Force Switzerland Swiss Air Force Turkey Turkish Air Force - Four aircraft, in service from 1921 to 1924. United Kingdom Royal Flying Corps Royal Naval Air Service Royal Air Force United States American Expeditionary Force United States Marine Corps Uruguay Uruguayan Air Force Civil operators Australia Qantas Belgium Sabena SNETA Denmark Det Danske Luftfartselskab Netherlands KLM Romania SNNA Spain Kingdom of Spain Cia Espanola del Trafico Aereo United Kingdom Aircraft Transport and Travel Handley Page Transport Bikaner State Maharaja Ganga Singh Surviving aircraft Of the thousands of DH.9s built, only a few survived to be preserved: 1. F1258 is displayed at the Musée de l'Air et de l'Espace in Paris. 2. An original DH.9 is displayed without serial number at the South African National Museum of Military History. This DH.9 flew with the South African Air Force after World War I, then was operated as a civilian aircraft as ZS-AOI, before returning to the SAAF. 3. G-EAQM (original RAF serial F1278) was the first single-engined aircraft to fly from the United Kingdom to Australia and is preserved at the Australian War Memorial in Canberra. In 2000, the remains of three DH.9s were discovered in India and two were retrieved for restoration in the UK. Of these. 1. D5649 was restored and is displayed at the Imperial War Museum, Duxford. 2. E8894/G-CDLI was restored to airworthy condition and is operated as a warbird by the Historic Aircraft Company in England. 3. The third was retained in India and restored to a somewhat less-than-faithful condition for display at Junargh Fort in the city of Bikaner, Rajasthan. Specifications (DH.9 (Puma Engine)) (Data from The British Bomber since 1914, Aircraft Profile No. 62: The de Havilland D.H.9.) General characteristics Crew: two Length: 30 ft 5 in (9.27 m) Wingspan: 42 ft 4+5⁄8 in (12.919 m) Height: 11 ft 3+1⁄2 in (3.442 m) Wing area: 434 sq ft (40.3 m2) Airfoil: RAF-16 Empty weight: 2,360 lb (1,070 kg) Gross weight: 3,790 lb (1,719 kg) Powerplant: 1 × Armstrong Siddeley Puma 6 cylinder inline piston engine, 230 hp (170 kW) Performance Maximum speed: 113 mph (182 km/h, 98 kn) Endurance: 4+1/2 hours Service ceiling: 15,500 ft (4,700 m) Time to altitude: 18 min 30 sec to 10,000 ft (3,000 m) Armament Guns: Forward firing .303 in (7.7 mm) Vickers machine gun and 1 or 2 × .303 in (7.7 mm) Lewis guns on scarff ring in rear cockpit Bombs: Up to 460 lb (210 kg) bombs Related development Airco DH.4 Airco DH.9A Aircraft of comparable role, configuration, and era Breguet 14 Airco DH.9 DH-9 G-AUED modified with a cabin for use as an airliner Handley Page H.P. 17 showing slots DH.9 operators Greek DH-9 Turkish DH-9 DH.9 F1258 at the Musée de l'Air et de l'Espace, Paris Le Bourget Airco DH.9 drawing Airco DH.9A DH.9A Role - Light bomber/General purpose Manufacturer - Airco First flight - March 1918 Introduction - 1918 Retired - 1931 Primary users - Royal Air Force / Soviet Air Forces / Royal Australian Air Force Number built - 1,997 + 2,400+ as R.1 Developed from - Airco DH.9 Variants - Westland Walrus / de Havilland DH.15 The Airco DH.9A is a British single-engined light bomber that was designed and first used shortly before the end of the First World War. It was a development of the unsuccessful Airco DH.9 bomber, featuring a strengthened structure and, crucially, replacing the under-powered and unreliable inline 6-cylinder Siddeley Puma engine of the DH.9 with the American V-12 Liberty engine. Colloquially known as the "Ninak" (from the phonetic alphabet treatment of designation "nine-A"), it served on in large numbers for the Royal Air Force following the end of the war, both at home and overseas, where it was used for colonial policing in the Middle East, finally being retired in 1931. Over 2,400 examples of an unlicensed version, the Polikarpov R-1, were built in the Soviet Union, the type serving as the standard Soviet light bomber and reconnaissance aircraft through the 1920s. Design and development The DH.9A was planned as an improved version of the existing Airco DH.9. The DH.9 was a disappointment owing to its under-performing and unreliable engines, and the DH.9A was to use a more powerful engine to resolve this. As the Rolls-Royce Eagle engine used in the successful DH.4 was unavailable in sufficient quantities, the new American 400 hp (300 kW) Liberty engine was chosen instead. As Airco was busy developing the Airco DH.10 Amiens twin-engined bomber, detailed design was carried out by Westland Aircraft. The DH.9 was fitted with new, longer-span wings and a strengthened fuselage structure. The first prototype flew in March 1918, powered by a Rolls-Royce Eagle as no Liberty engines were yet available. The prototype proved successful, with the first Liberty-engined DH.9A flying on 19 April 1918, and deliveries to the Royal Air Force starting in June. By the end of the war, a total of 2,250 DH.9As had been ordered, with 885 being built by the end of the year. As it was decided that the DH.9A would be a standard type in the postwar RAF, the majority of outstanding orders were fulfilled, with 1,730 being built under the wartime contracts before production ceased in 1919. While the existing aircraft were subject to a programme of refurbishment, a number of small contracts were placed for new production of DH.9As in 1925-26. These contracts resulted in a further 268 DH.9As being built. The new production and refurbished aircraft included batches of dual control trainers, as well as six aircraft powered by 465 hp (347 kW) Napier Lion engines, which were capable of a maximum speed of 144 mph (232 km/h). The Soviet Union built large numbers of an unlicensed copy of the DH.9A, the R-1. After the production of 20 DH.4 copies, followed by about 200 copies of the DH.9 powered by the Mercedes D.IV engine (also designated R-1) and a further 130 powered by the Siddeley Puma (designated R-2), a copy of the DH.9A powered by the M-5 engine, a Soviet copy of the DH.9A's Liberty, entered production in 1924. The Polikarpov R-4 was a modification of the R-1, with the engine lowered and moved forward by 140 mm (5.5 in) to improve both the forward visibility and the C.G position. The nose shape was improved by fairing and by installing a retractable ventral radiator. Overall length was increased by 389 mm (15.3 in). Landing legs were changed from wood to steel. Testing showed insufficient improvement over the R-1 to justify production but late R-1s incorporated some of the modifications. US version and pressurised flights The United States also planned to adopt the DH.9A as a replacement for the DH.4. Development work on the Americanization of the aircraft commenced at McCook Field in Dayton, Ohio. Modifications included a new fuel system with increased fuel capacity, revised wings and tail surfaces, and replacement of the Vickers machine gun on the port side of the British built aircraft with a Browning machine gun on the starboard side. Plans called for Curtiss to build 4,000 modified aircraft, designated USD-9A. This order was cancelled with the end of the war and only nine were built by McCook Field and Dayton-Wright. One McCook aircraft was additionally modified with an enclosed, pressurised cockpit. In 1921, test pilot Lt. Harold R. Harris made the world's first high-altitude flight in a pressurised aircraft in the USD-9A at McCook Field in Dayton, Ohio. Operational history First World War The DH.9A entered service in July 1918 with No. 110 Squadron RAF, moving to France on 31 August 1918 to serve with the RAF's Independent Air Force on strategic bombing missions. Its first mission was against a German airfield on 14 September 1918. A further three squadrons commenced operations over the Western Front before the Armistice, with 99 Squadron (also serving with the Independent Air Force) replacing DH.9s, while 18 Squadron and 216 Squadron replaced DH.4s. Despite the superior performance of the DH.9A over the DH.9, the DH.9A squadrons suffered high losses during their long range bombing missions over Germany. Other squadrons flew coastal patrols from Great Yarmouth before the end of the year. The United States Marine Corps Northern Bombing Group received at least 53 DH-9As, and commenced operations in September 1918. Interwar RAF service While the squadrons in service at the end of the First World War quickly disbanded or re-equipped in the postwar dis-armament, the DH.9A continued in service as the RAF's standard light bomber, with 24 squadrons being equipped between 1920 and 1931, both at home and abroad. The first post war operations were in southern Russia during 1919, in support of the "White Army" against the Bolsheviks during the Russian Civil War. In September 1919, the RAF personnel were ordered to return home, leaving their aircraft behind. A squadron of DH.9As was deployed to Turkey in response to the Chanak Crisis in 1922, but did not engage in combat. The DH.9A was one of the key weapons used by Britain to manage the territories that were in its control following the collapse of the Ottoman Empire following the Great War. Five squadrons of DH.9As served in the Middle East, occasionally carrying out bombing raids against rebellious tribesmen and villages. An additional radiator was fitted under the fuselage to cope with the high temperatures, while additional water containers and spares (including spare wheels lashed to the fuselage) were carried in case the aircraft were forced down in the desert, the DH.9A's struggling under ever heavier loads. Despite this the aircraft served successfully, with the Liberty engine being picked out for particular praise for its reliability ("as good as any Rolls Royce") in such harsh conditions. Some DH.9A aircraft were also transported to India to supplement the British Indian Army. At home, the DH.9A continued on in regular RAF service until 1930, also forming the initial equipment of the Royal Auxiliary Air Force (RAuxAF). Soviet service The R-1 and R-2 were heavily used by the Soviet Air Forces through the 1920s as its standard light bomber and reconnaissance aircraft. The Soviets deployed them in support of the Chinese Kuomintang forces in the Northern Expedition against warlords in 1926-27, and against Chinese forces for control of the Chinese Eastern Railway in Manchuria in 1929. R-1s and R-2s were also used in support of operations during the Basmachi Revolt in central Asia. Variants Airco DH.9A: Original version. de Havilland DH.9AJ: Single prototype with Bristol Jupiter engine. de Havilland DH.9R: Racing aircraft with sesquiplane wings and powered with a Napier Lion engine - (one built). Airco DH.15 Gazelle: DH.9A fitted with a BHP Atlantic inline engine, one conversion. Airco DH.16: Civil transport with widened fuselage seating four passengers in a glazed cabin behind the pilot, who sat in an open cabin, nine built. Rolls Royce Eagle or Napier Lion Engine. de Havilland DH-49: Proposed modernised version with Eagle IX engine (not built) Engineering Division USD-9A: United States built version, 9 built. One modified with a pressurised cockpit. Engineering Division USD-9B: USD-9A fitted with more powerful Liberty engine and greater area wings. Armstrong Whitworth Tadpole: One prototype conversion for a naval three-seat spotter/reconnaissance aircraft. Westland Walrus: Production version of the Tadpole conversion with the Napier Lion III engine (36 built). Polikarpov R-1 and R-2: Copy of DH.9A built in the Soviet Union, originally at the Dux Factory, supervised by Nikolai Nikolaevich Polikarpov. Early aircraft were powered by Mercedes D.IV or Armstrong Siddeley Puma engines, but most were powered by the M-5 copy of the Liberty Engine. Over 2,400 built from 1922 to 1932. Polikarpov R-1 BMW: R-1 fitted a 240 hp (180 kW) BMW IVa engine, 20 built. Polikarpov MR-1: Twin-float seaplane version, 124 built. Polikarpov PM-2: Prototype floatplane fitted with metal floats. Polikarpov R-4: R-1 with better forward view and CG position, forward profile cleaned up with fairings and a retractable ventral radiator. Stronger landing gear. No production but changes incorporated into late R-1s. Operators Afghanistan Afghan Air Force: Airco DH.9As and Polikarpov R-1s Australia Royal Australian Air Force: 30 received as an imperial gift in 1920 plus one attrition replacement purchased in 1921 (The aircraft were in service from 1920 to 1930.) No. 1 Flying Training School RAAF (22 aircraft: A1-1/2/5/7-11/13-21/23/24/26/29/30) No. 1 Squadron RAAF (12 aircraft: A1-4/5/7/9/12/14/20-22/25/26/28) No. 3 Squadron RAAF (8 aircraft: A1-3/6/8/10/24/25/27/28) Central Flying School RAAF (4 aircraft: A1-16/17/26, E8616) Canada Canadian Air Force (1918-1920) No. 2 Squadron CAF Canadian Air Force (1920-1924) Royal Canadian Air Force Iran Imperial Iranian Air Force Latvia Latvian Air Force Mongolia Mongolian People's Air Force: Polikarpov R-1s and R-2s Portugal Portuguese Air Force Switzerland Swiss Air Force: One aircraft only United Kingdom Royal Air Force No. 3 Squadron RAF No. 8 Squadron RAF No. 11 Squadron RAF No. 14 Squadron RAF No. 15 Squadron RAF No. 18 Squadron RAF No. 22 Squadron RAF No. 24 Squadron RAF No. 25 Squadron RAF No. 30 Squadron RAF No. 39 Squadron RAF No. 45 Squadron RAF No. 47 Squadron RAF No. 55 Squadron RAF No. 60 Squadron RAF No. 84 Squadron RAF No. 99 Squadron RAF No. 100 Squadron RAF No. 110 Squadron RAF No. 205 Squadron RAF No. 207 Squadron RAF No. 207 Squadron RAF No. 221 Squadron RAF No. 273 Squadron RAF No. 501 Squadron RAF No. 600 Squadron RAF No. 601 Squadron RAF No. 602 Squadron RAF No. 603 Squadron RAF No. 604 Squadron RAF No. 605 Squadron RAF United States United States Navy United States Marine Corps Soviet Union Soviet Air Force: Polikarpov R-1s and R-2s Surviving aircraft A single example, serial number F1010, survives and is on display at the Royal Air Force Museum London. The aircraft was completed by Westland Aircraft in June 1918 and was one of 18 DH.9A's assigned to No. 110 Squadron RAF. It was the thirteenth aircraft, but was given the number "12A" because thirteen was thought unlucky. The squadron began flying bombing missions in September 1918, and on the 25th, the crew of F1010 claimed the destruction of a German Fokker D.VII fighter. The aircraft's fourth and final combat mission was on 5 October when either flak damage or engine trouble forced a landing behind German lines. The aircraft was undamaged by the landing and the crew were taken prisoner. The aircraft remained in German hands after the war and in 1936 it was put on display at the Deutsche Luftfahrt Sammlung (Berlin Air Museum), one of the museum's substantial collection of World War 1 aircraft. In 1943, it was one of the museum's exhibits that was moved to Czarnikau (now Czarnkow in Poland) to save them from the Allied bombing of Berlin. The area was captured by Polish forces in March 1945 and F1010 eventually became part of the collection of the Polish Aviation Museum, although it was not put on display and remained in the museum's stores. In 1977, the Polish Aviation Museum exchanged F1010 for a Supermarine Spitfire from the RAF Museum (difficulties caused by the Cold War meant nearly nine years were spent negotiating the swap). The RAF Museum completed restoration of the aircraft and put it on display in 1983. Specifications (DH.9A) (Data from The British Bomber since 1914) General characteristics Crew: 2 Length: 30 ft 3 in (9.22 m) Wingspan: 45 ft 11+3⁄8 in (14.005 m) Height: 11 ft 4 in (3.45 m) Wing area: 486.75 sq ft (45.221 m2) Empty weight: 2,800 lb (1,270 kg) Max takeoff weight: 4,645 lb (2,107 kg) Powerplant: 1 × Liberty 12A water-cooled V-12 engine, 400 hp (300 kW) Performance Maximum speed: 123 mph (198 km/h, 107 kn) at sea level, 114.5 mph (184.3 km/h; 99.5 kn) at 10,000 ft (3,000 m) Endurance: 5 h 25 min Service ceiling: 16,750 ft (5,110 m) Time to altitude: 15 min 45 s to 10,000 ft (3,000 m) Armament Guns: ** 1× forward firing .303 in (7.7 mm) Vickers machine gun, 1 or 2 × .303 in (7.7 mm) Lewis guns on Scarff ring Bombs: Up to 740 lb (340 kg) on underwing and fuselage racks Related development Airco DH.9 Westland Wapiti Westland Wallace Airco D.H.9A Polikarpov R-1 DH.9A number F1010 at the RAF Museum, London in 2010 Polikarpov R-1 Airco DH.9C DH.9C Role - passenger National origin - United Kingdom Manufacturer - Airco First flight - late 1921 Number built - 19 Developed from - Airco DH.9 The Airco DH.9C was a British passenger aircraft. Development and design After World War I there were many surplus Airco DH.9 light bombers, designed by Geoffrey de Havilland, available for the emerging air transport business. At first stripped DH.9s were used to carry one passenger behind the pilot in the gunner's position, but later versions, designated DH.9B, added a second passenger seat ahead of the pilot. A second seat behind the pilot was added by extending the rear cockpit in the early DH.9C. Later it had this rear position converted to hold two passengers face to face, protected by a faired dorsal canopy or cabin. Most of these later four-seat aircraft had slight sweepback to counter the rearward shift in the centre of gravity. The DH.9, DH.9B, and DH.9C were dimensionally similar, with the same wingspan and height and only small variations in length depending on the powerplant. They were two-bay tractor biplanes, with fixed two-wheel main and tail-skid undercarriage. Their structures were of spruce and ash, wire-braced and fabric-covered. The first four-seat, swept DH.9C, G-EAYT received its certificate of airworthiness on 13 January 1922. Operational history Nineteen aircraft were produced for operators, 13 in the United Kingdom, three in Australia, and three in Spain. The last in service was operated by Northern Air Lines in Barton, Greater Manchester, until 1932. Operators Australia Qantas (3 aircraft) Morlae Airways (1 aircraft) Belgium Sneta (precursor to Sabena) (1 aircraft) Kingdom of Hejaz Hejaz Air Force (2 aircraft) Netherlands KLM (1 aircraft) Spain Compañía Española de Tráfico Aéreo (CETA) (3 aircraft) United Kingdom The de Havilland Aeroplane Hire Service (7 aircraft) Northern Air Lines (2 aircraft) Specifications General characteristics Crew: 1 Capacity: 4 (3 passengers) Length: 30 ft 6 in (9.30 m) Wingspan: 42 ft 4.63 in (12.92 m) Height: 11 ft 2 in (3.40 m) Wing area: 434 sq ft (40.3 m2) Empty weight: 2,600 lb (1,179 kg) Gross weight: 3,300 lb (1,497 kg) Powerplant: 1 × Siddeley Puma , 230 hp (172 kW) Performance Maximum speed: 115 mph (185 km/h, 100 kn) Cruise speed: 95 mph (153 km/h, 83 kn) Range: 500 mi (805 km, 430 nmi) Service ceiling: 19,000 ft (5,790 m) Rate of climb: 660 ft/min (3.35 m/s) Related development Airco DH.9 Airco DH.9A Airco DH.9B Australian registered DH.9C G-AUED c.1923 Airco DH.10 Amiens DH.10 Amiens Role - Heavy bomber Manufacturer - Airco Designer - Geoffrey de Havilland First flight - 4 March 1918 Introduction - November 1918 Retired - 1923 Primary user - Royal Air Force Number built - 258 Developed into - de Havilland DH.11 Oxford The Airco DH.10 Amiens was a twin-engined heavy bomber designed and produced by the British aircraft manufacturer Airco. It performed the first nighttime air mail service in the world on 14-15 May 1919. The DH.10 was developed in the final years of the First World War in response to a requirement to equip the newly-formed Royal Air Force (RAF) with an expanded offensive bombing capability. It was based upon the earlier Airco DH.3 bomber, which had not been pursued largely due to disinterest in heavy bombers at that time. The first prototype performed its maiden flight on 4 March 1918; dissatisfaction with its performance led to the aircraft being redesigned with more powerful engines and a tractor configuration, which was received more favourably. Over 1,200 DH.10s were on order at one stage. Only a handful of DH.10s had been delivered to the RAF, and a single offensive mission conducted, before the Armistice of 11 November 1918 came into effect, ending the conflict. The diminishing need for bombers meant orders for the type were reduced and production was scaled back substantially. Nevertheless, over 250 DH.10s were constructed and were operated during the interwar period, seeing use in the Third Anglo-Afghan war as well as for air mail services in various regions. The type was replaced by more capable bombers during the early 1920s. Design and development Background The origins of the DH.10 can be largely traced back to April 1917 and the Air Board's issuing of Specification A.2.b, which sought a new day bomber, powered either by single or twin-engines. Stipulations of the requirement included up to 500 lb of bombs, at least two guns with 150 lb of ammunition, and the ability to fly at least 110 mph at an altitude of 15,000 feet when fully loaded. A good means of communication between the crew was also mentioned, as well as for the aircraft to be capable of staying afloat for at least three hours in the event of a water landing. In late 1917, Airco decided to respond to A.2.b, with the work headed by the aeronautical engineer Geoffrey de Havilland. The proposal was heavily derived from the company's earlier 320 hp (240 kW) DH.3A bomber, which had flown in 1916 but had been rejected by the War Office largely due to a lack of engine power resulting in a dismal climb rate - taking 58 minutes to reach 6,500 feet, which made strategic bombing with it impractical, while the other submission for the role, the Royal Aircraft Factory F.E.4 had fared even worse. In comparison to the DH.3, the proposed aircraft, which was designated DH.10, shared a broadly similar configuration but was slightly larger. While also equipped with twin engines, more powerful Siddeley Puma engines, each capable of generating up to 230 hp (170 kW), were adopted for the aircraft in a pusher arrangement. It was also designed as a three-seater, an arrangement that met with official acceptance despite the specification having called for a crew of two. Having been sufficiently impressed with the proposal, the company was issued with Contract No. AS.31576 for a total of four prototypes to be constructed. Into flight The first prototype, C8858, conducted its maiden flight on 4 March 1918. Originally, the first flight had been intended to occur in January 1918, but its completion had been delayed due to labour issues and the late delivery of components. During its service evaluation at Martlesham Heath one month later, the performance of this prototype was determined to be beneath expectations, attaining only 90 mph (140 km/h) at 15,000 ft (4,600 m) with the required bomb load, compared with the specified 110 mph (180 km/h). Owing to this poor performance, the DH.10 was redesigned with more powerful engines in a tractor installation. The second prototype, C8959, known as the Amiens Mark.II, was powered by two 360 hp (270 kW) Rolls-Royce Eagle VIII engines. It made its first flight on 20 April 1918 and was test flown by Airco for roughly two months. It demonstrated superior performance, proving to be faster than the single engine Airco DH.9A while carrying twice the bomb load, that the company decided to adopt the tractor configuration for all future aircraft. While shortages of the Eagle meant that the Amiens Mark.II could not be put into production, it proved the design of the definitive aircraft. The third design, Amiens Mark III, prototypes C8860 and C4283, which was powered by the more readily available 395 hp (295 kW) Liberty 12 from America, as was the DH.9A. During June 1918, evaluation flights of the third prototype commenced; it was damaged in a crash at Martlesham Heath that summer, but was repaired. The fourth prototype was almost one-for-one identical with the subsequent production aircraft; it started official evaluations during August 1918. According to aviation author J.M. Bruce, confidence in the DH.10 was relatively high amongst officials. Following its successful evaluation, several large orders were placed, totalling 1,291 aircraft on order at one point. Production By 22 March 1918, production contracts had been placed with five separate manufacturers, covering a total of 800 aircraft, even prior to the completion of the first prototype's evaluation. Further contracts followed in June and July of that year for 475 aircraft from Airco, Alliance and Mann Egerton. Production of the Liberty engine, which was lower than anticipated, served to restrain the DH.10's rate of production, leading to a revival in interest in the Rolls-Royce Eagle engine. The vehicle manufacturer Daimler were producing 80 DH.10s per month by the end of 1918. They were part of the Birmingham Small Arms (BSA) group which purchased Airco after the conflict, and launched a charter and scheduled service known as Daimler Air Hire and Daimler Airway. Apart from the Aircraft Manufacturing Company's order for 420 aircraft, the following companies had subcontracts to build the DH.10, although due to the end of the war not all were built: The Birmingham Carriage Company - 100 Daimler Limited - 150 National Aircraft Factory No.2 (Heaton Chapel) - 200 The Siddeley-Deasy Car Company - 150 The Alliance Aero Company - 200 Mann, Egerton & Company - 75 By June 1920, surplus DH.10s were being advertised for sale to interested parties, both domestic and international ones. Operational history At an early stage of the DH.10's development, it had been anticipated that the aircraft was to equip eight squadrons of the Independent Air Force (IAF) by 1919. By 31 October 1918, less than two weeks from the end of the conflict, only eight aircraft had been delivered to the RAF, including to the IAF. No. 104 Squadron (41st Wing, VIII Brigade) flew a single bombing mission, on 10 November 1918, prior to the Armistice that ended the First World War came into effect. In September 1918, the IAF filed a request for greater endurance, leading to a 40-gallon auxiliary tank being rapidly designed and deployed one month later. Early operations of the DH.10 were often troubled by the somewhat unusual fuel system, which was attributed as being involved in multiple crashes on takeoff; Bruce notes that fuel starvation occurred as late as May 1920. Following the conflict, use of the type was somewhat curtailed. A number of DH.10s equipped No. 120 Squadron, which used them to operate an air mail service in support of the British Army of Occupation on the Rhine. One of the squadron's DH.10s became the first aircraft in the world to undertake a nighttime air service, flying between Hawkinge and Cologne on 14-15 June 1919. The DH.10 was also used by No. 97 Squadron (later renumbered No. 60 Squadron) during its deployment to India, starting in 1919. The type provided support to the Army on the North-West Frontier, and saw active combat in this capacity, performing bombing operations on multiple occasions during the Third Anglo-Afghan war. Specifically, DH.10s conducted reprisal attacks at Datta Khel and Abdur Rahman Khel, amongst other sorties made. Due to the hot climate, its performance was diminished somewhat, thus enlarged radiators were typically fitted. DH.10s were also operated by No. 216 Squadron in Egypt, where they provided a regular air mail service between Cairo and Baghdad; this started on 23 June 1921, the type was withdrawn from the role during 1923. The final DH.10 in operation was used for experimental purposes, including a series of single-engine test flights, with the Royal Aircraft Establishment (RAE) at Farnborough Airfield. Variants Amiens Mk.I Prototype powered by two pusher Puma engines. Amiens Mk.II Prototype powered by two tractor Rolls-Royce Eagle engines. Amiens Mk.III Main production variant, powered by Liberty L-12 engines mounted midway between wings, 221 built. Amiens Mk.IIIA (DH.10A) Modified Mark III with engines directly attached to lower wings, larger wheels of 1.2 m (3 ft 11 in) diameter. 32 built. Amiens Mk.IIIC (DH.10C) Mark IIIA powered by Rolls-Royce Eagle engines. Designed in response to the shortage of Liberty engines. Five built. A DH.10B designation existed but what it referred to is uncertain; Bruce suggests a Mk III with Eagle engines replacing the Libertys mounted in same place between the upper and lower wings. A DH.10 and a DH.10C were modified to take the 37mm Coventry Ordnance Works (COW) gun; the fuselage was extended forward and nosewheels fitted. The aircraft were sent for testing at the armament experimental unit, Orfordness. Operators Military operators United Kingdom Royal Air Force No. 24 Squadron - used a single DH.10 for communications duties in 1920. No. 27 Squadron - operated two DH.10s for operations over the North-West Frontier in December 1922. No. 51 Squadron - evaluated a single DH.10 as a home defence fighter in 1918. No. 60 Squadron - April 1920 to April 1923. No. 97 Squadron - March 1919 to April 1920. No. 104 Squadron - November 1918 to June 1919. No. 120 Squadron - used a single DH.10 for night air mail trials in May 1919. No. 216 Squadron - August 1920 to June 1922. Civil operators United Kingdom Aircraft Transport and Travel Ltd operated the only DH.10 placed on the British Civil Register. This aircraft, G-EAJO, was used for regular airmail flights between Hendon and Renfrew during the railway strike in October 1919. It was destroyed in a crash in April 1920. United States At least one DH.10 was used for US Post Office air mail services on the New York City - Cleveland - Omaha route in 1920. Specifications (Amiens IIIA) (Data from The British Bomber since 1914) General characteristics Crew: Three Length: 39 ft 7+7⁄16 in (12.076 m) Wingspan: 65 ft 6 in (19.96 m) Height: 14 ft 6 in (4.42 m) Wing area: 837.4 sq ft (77.80 m2) Empty weight: 5,750 lb (2,608 kg) Gross weight: 8,500 lb (3,856 kg) Max takeoff weight: 9,060 lb (4,110 kg) Powerplant: 2 × Liberty 12 water-cooled V-12 engines, 400 hp (300 kW) each Propellers: 2-bladed wood fixed pitch propellers Performance Maximum speed: 131 mph (211 km/h, 114 kn) at sea level, 124 mph (200 km/h) at 10,000 feet (3,000 m) Endurance: Six hours Service ceiling: 19,000 ft (5,800 m) Time to altitude: 11 minutes to 10,000 ft (3,000 m) Armament Guns: 1 or 2 × .303 in (7.7 mm) Lewis guns on Scarff rings at both nose and midships gunners cockpits Bombs: Up to 920 lb (420 kg) bombs carried internally Related development Airco DH.3 de Havilland DH.11 Oxford Aircraft of comparable role, configuration, and era Boulton Paul Bourges Vickers Vimy Australian registered DH.9C G-AUED c.1923 Airco DH.11 Oxford DH.11 Oxford Role - Bomber Manufacturer - Airco Designer - Geoffrey de Havilland First flight - January 1919 Status - Abandoned Number built - One Developed from - Airco DH.10 Amiens The Airco DH.11 Oxford (later de Havilland) was a British twin-engined biplane bomber which was designed to replace the earlier Airco DH.10 Amiens. It was designed to use the unsuccessful ABC Dragonfly engine and was abandoned after the first prototype was built. Development The DH.11 Oxford was designed by Geoffrey de Havilland for the Aircraft Manufacturing Company as a twin-engined day bomber to replace the Airco DH.10 Amiens. It was designed (as required by the Specification) to use the ABC Dragonfly radial engine which promised to give excellent performance and had been ordered in large numbers to be the powerplant for most of the new types on order for the Royal Air Force. The DH.11 was a twin-engined biplane, with all-wood construction and three-bay wings. It had an aerodynamically clean, deep fuselage occupying the whole wing gap, giving a good field of fire for the gunners in the nose and mid-upper positions. The first prototype flew in January 1919, powered by two 320 hp (239 kW) Dragonfly engines. The prototype encountered handling problems, and was handicapped by the Dragonfly engines, which were extremely unreliable, being prone to overheating and excessive vibration, while not delivering the expected power. Two further prototypes were cancelled in 1919, with no aircraft in the end being purchased to replace the DH.10. Variants Oxford Mk I - Prototype - powered by two 320 hp (240 kW) ABC Dragonfly engines - one built. Oxford Mk II - Proposed version with two 300 hp (220 kW) Siddeley Puma engines - not built. DH.12 - Proposed version with Dragonfly engines and modified gunner's position - not built. Specifications (Oxford Mk I) (Data from The British Bomber since 1914) General characteristics Crew: 3 Length: 45 ft 2+3⁄4 in (13.786 m) Wingspan: 60 ft 2 in (18.34 m) Height: 13 ft 6 in (4.11 m) Wing area: 719 sq ft (66.8 m2) Empty weight: 4,105 lb (1,862 kg) Max takeoff weight: 7,027 lb (3,187 kg) Powerplant: 2 × ABC Dragonfly air-cooled 9-cylinder radial engines, 320 hp (240 kW) each Propellers: 2-bladed wood fixed pitch propellers Performance Maximum speed: 123 mph (198 km/h, 107 kn) at sea level, 116 mph (187 km/h) at 10,000 ft (3,000 m) Endurance: 3 hr Service ceiling: 14,500 ft (4,400 m) Time to altitude: 13 min 45 s to 10,000 ft (3,000 m) Armament Guns: 1 × .303 in (7.7 mm) Lewis gun at Scarff rings at both nose and midships gunners cockpits Bombs: 4 × 230 lb (100 kg) bombs internally Related development - Airco DH.10 Amiens Aircraft of comparable role, configuration, and era - Avro 533 Manchester - Nieuport London - Vickers Vimy de Havilland DH.14 Okapi (Airco DH.14) DH.14 Okapi Role - Day bomber National origin - United Kingdom Manufacturer - Airco / de Havilland First flight - 1919 Status - abandoned prototype Primary user - Royal Air Force (trials only) Number built - 3 The de Havilland DH.14 Okapi was a British two-seat day bomber of the 1910s built by de Havilland. The aircraft was designed as an Airco DH.4 and DH.9 replacement, but it never entered production. Design and development The Okapi was a scaled-up Airco DH.9 with a bigger engine, (the Rolls-Royce Condor) intended as a replacement for the DH.4 and DH.9. Three were built, but due to the end of the First World War the Royal Air Force was reluctant to accept them. The third aircraft was the first to fly, and it was completed by Airco as the DH.14A, a two-seat long-range mail plane. The two military aircraft were completed by de Havilland in 1921 and used for trials. One suffered a fatal crash at Burnham Beeches on 10 February 1922 and no production aircraft were ordered. G-EAPY The third aircraft was completed as the DH.14A to compete in the Daily Mail transatlantic flight competition. It had a Napier Lion engine and increased 586 imp gal (2,660 L; 704 US gal) fuel capacity. With the winning of the prize by Alcock and Brown the project was abandoned. The aircraft, registered G-EAPY, was then to be used by Sidney Cotton, who intended to try for the Australian government's £10,000 prize for a flight between England and Australia. Keith and Ross Smith won that prize before Cotton was ready. The aircraft was loaned by Airco to Cotton to attempt the first flight between London and Cape Town. Cotton and an engineer from Napier left Hendon Aerodrome on 4 February 1920, but soon forced landed at Cricklewood with oil problems. Cotton reached Naples on the 21 February but they failed to find the aerodrome at Messina and they force-landed on a nearby beach. G-EAPY was rebuilt by Airco with an additional third cockpit and sold to Cotton for use in the Aerial Derby. The aircraft was badly damaged when it forced landed following an onboard fire near Hertford on 24 July 1920. When the other two DH.14s were completed by de Havilland at Stag Lane in 1921 the DH.14A was repaired again and joined the test flying with a military serial number. Variants DH.14 - two-seat day bomber with a Rolls-Royce Condor engine, two built. DH.14A - two-seat long range mailplane with a Napier Lion Engine, one built. Operators - United Kingdom - Royal Air Force Specifications (DH.14) (Data from The British Bomber since 1914) General characteristics Crew: Two Length: 33 ft 11+1⁄2 in (10.351 m) Wingspan: 50 ft 5 in (15.37 m) Height: 14 ft 0 in (4.27 m) Wing area: 617 sq ft (57.3 m2) Empty weight: 4,484 lb (2,034 kg) Max takeoff weight: 7,074 lb (3,209 kg) Powerplant: 1 × Rolls-Royce Condor I water-cooled V12 engine, 525 hp (391 kW) Propellers: wood fixed pitch propeller Performance Maximum speed: 122 mph (196 km/h, 106 kn) at 10,000 ft (3,000 m) Endurance: 5 hours Rate of climb: 400 ft/min (2.0 m/s) Armament Guns: 1 × fixed forward-firing synchronised 0.303 in (7.7 mm) Vickers machine gun / 1 × 0.303 in (7.7 mm) Lewis gun on Scarff ring Bombs: 6 × 112 lb (51 kg) bombs in two fuselage bomb bays De Havilland DH.15 DH.15 Role - Engine test bed National origin - United Kingdom Manufacturer - The Aircraft Manufacturing Co. Ltd. Status - abandoned Number built - 1 Developed from - de Havilland DH.9A The de Havilland DH.15 Gazelle was an engine testbed for the B.H.P Atlantic engine, converted from a de Havilland DH.9A for flight trials in 1919-20. Only one was built. Development The DH.15 Gazelle, more often known just as the DH.15, was a standard DH.9A, complete with original armament, converted for use as an engine testbed. The engine involved was the 500 hp (373 kW) B.H.P. Atlantic, a water-cooled V-12 unit produced by the Galloway Engineering Co., which merged two six-cylinder inline B.H.P. engines onto a common crankcase. This replaced the DH.9A's standard 400 hp (300 kW) Liberty 12, although without a great change in appearance, as the Atlantic was mounted behind a similar large rectangular radiator. Both engines were upright V-12s, both with crankshafts near the base, and in each case, the propeller was mounted low on the nose. The exhaust pipes on the DH.15 were longer than the usual DH.9A set, running straight back from the upper sides of the engine, ending at the observer's cockpit. Two DH.15s were ordered, but only one was built. It completed many flights with the Atlantic engine from 1919 to 1920. Specifications General characteristics Crew: Two Length: 29 ft 11 in (9.12 m) Wingspan: 45 ft 11+3⁄8 in (14.005 m) Wing area: 486+3⁄4 sq ft (45.22 m2) Empty weight: 2,312 lb (1,049 kg) Gross weight: 4,773 lb (2,165 kg) Powerplant: 1 × Galloway Atlantic water-cooled V12 engine, 500 hp (370 kW) Performance Maximum speed: 139 mph (224 km/h, 121 kn) Service ceiling: 20,000 ft (6,100 m) Rate of climb: 1,500 ft/min (7.6 m/s) Armament Guns: 1 × forward firing .303 in (7.7 mm) Vickers machine gun / 1 × .303 in (7.7 mm) Lewis gun on Scarff ring Bombs: Up to 460 lb (210 kg) bombs Airco DH.16 DH.16 Role - commercial biplane Manufacturer - Airco First flight - 1919 Introduction - 1919 Retired - 1923 Primary user - Aircraft Transport and Travel Number built - 9 The Airco DH.16 was an early British airliner designed by Geoffrey de Havilland, the chief designer at Airco. It accommodated a pilot plus four passengers, and was operated from 1919 to 1923. Design and development The DH.16 was a redesigned Airco DH.9A light bomber biplane with a wider fuselage, accommodating an enclosed cabin seating four passengers, plus the pilot in an open cockpit. In March 1919, the prototype first flew at Hendon Aerodrome. Nine aircraft were built, all but one being delivered to Airco's subsidiary Aircraft Transport & Travel Limited (AT&T). Operational History AT&T used the first aircraft for pleasure flying, then on 25 August 1919 it was with this type of aircraft that AT&T operated the first regular (daily) international service in the world, from London-Hounslow Heath Aerodrome to Paris-Le Bourget Airport. On 17 May 1920, an AT&T DH.16 (G-EALU) flew the first KLM service between Croydon Airport and Amsterdam Airport Schiphol. In December 1920, AT&T closed down. One aircraft was sold to the River Plate Aviation Company in Argentina, to operate a cross-river service between Buenos Aires and Montevideo, and the other aircraft were stored. Two were later used for newspaper delivery flights, but on 10 January 1923 one of these suffered a fatal crash, and the remaining DH.16s were withdrawn and scrapped. Variants The first six aircraft were powered by a 320 hp (239 kW) Rolls-Royce Eagle inline piston engine; the last three aircraft were fitted with the more powerful 450 hp (336 kW) Napier Lion engine. Operators - Argentina River Plate Aviation Company - one former AT&T aircraft from 1920. - Netherlands KLM - services operated by Aircraft Transport and Travel aircraft. - United Kingdom Aircraft Transport and Travel Limited - all nine DH.16s operated from 1919 to 1922. De Havilland Aeroplane Hire Service - two former AT&T aircraft from 1922 to 1923. Specifications (DH.16 with Napier Lion engine) (Data from De Havilland Aircraft since 1909) General characteristics Crew: One Capacity: Four passengers Length: 31 ft 9 in (9.68 m) Wingspan: 46 ft 5+7⁄8 in (14.170 m) Height: 11 ft 4 in (3.45 m) Wing area: 489+3⁄4 sq ft (45.50 m2) Empty weight: 3,155 lb (1,431 kg) Max takeoff weight: 4,750 lb (2,155 kg) Powerplant: 1 × Napier Lion 12-cylinder water-cooled W-block aircraft piston engine, 450 hp (340 kW) Propellers: 4-bladed wood fixed pitch propeller Performance Maximum speed: 136 mph (219 km/h, 118 kn) Cruise speed: 100 mph (160 km/h, 87 kn) Range: 425 mi (684 km, 369 nmi) Service ceiling: 21,000 ft (6,400 m) Rate of climb: 1,000 ft/min (5.1 m/s) Related development Airco DH.9A De Havilland DH.18 Aircraft of comparable role, configuration, and era BAT F.K.26 Salmson 2 Limousine Vickers Vulcan DH.16 of Aircraft Transport & Travel Three-view of Airco DH.16 with Rolls-Royce Eagle engine from Flight, 2 October 1919 de Havilland DH.18 (Airco DH.18) DH.18 Role - Airliner Manufacturer - Airco Designer - Geoffrey de Havilland First flight - 8 April 1920 Introduction - 1920 Retired - 1923 Primary users - Aircraft Transport and Travel / Daimler Hire Ltd / Instone Air Line Produced - 1919-1921 Number built - 6 The de Havilland DH.18 was a single-engined British biplane transport aircraft of the 1920s built by de Havilland. Design and development The DH.18 was designed and built in 1919 by Airco as their first aircraft specifically for commercial work, earlier aircraft such as the DH.16 being modified military types. The DH.18 was a single-engined biplane, powered by a Napier Lion engine with wooden two-bay, wire-braced wings, and a forward fuselage clad in plywood. It accommodated eight passengers in an enclosed cabin with the pilot in an open cockpit behind the cabin. The first prototype flew early in 1920. Operational history The first DH.18 was delivered to Aircraft Transport and Travel for use on the Croydon-Paris service, but was wrecked in a forced landing shortly after takeoff from Croydon on 16 August 1920. Two more aircraft were under construction by Airco for Aircraft Transport and Travel when the bankrupt Airco was purchased by BSA, who did not wish to continue aircraft development or production. Geoffrey de Havilland, the chief designer of Airco then set up the de Havilland Aircraft Company, completing the two partly completed aircraft as DH.18As, with improved engine mountings and undercarriages. Aircraft Transport and Travel closed down in early 1921, due to competition from subsidised French airlines. In March 1921, the British government granted temporary subsidies for airline services, with the Air Council purchasing a number of modern commercial aircraft for leasing to approved firms. The three ex-A.T.&T. DH.18s were purchased in this way and leased to Instone Air Line. A further DH.18A was built to Air Council order, as were two modified DH.18B, which had fuselages that were entirely plywood-clad and had built-in emergency exits. The DH.18s were kept busy flying on continental air services for Instone, building up high flying hours. One aircraft, G-EAWO, was transferred to Daimler Airway for operation on the Croydon-Paris route until the de Havilland DH.34s which it had on order could be delivered. However, on 4 April 1922, two days after Daimler commenced operations with the aircraft, it collided with a Farman Goliath over Northern France, 62 mi (100 km) north of Paris, killing seven people, the first midair collision between airliners. The DH.18 was retired from commercial service in 1923, with one aircraft, G-EARO, having flown 90,000 mi (144,834 km) without accident. Two aircraft were used for test purposes, with one the subject of an Air Ministry experiment on how long an aircraft could stay afloat after being ditched, being deliberately landed on water off Felixstowe on 2 May 1924, floating for 25 minutes. The other remaining aircraft was used for test purposes at RAE Farnborough until 1927, when it was scrapped. Variants DH.18 Prototype - registered G-EARI. DH.18A Initial production version - modified undercarriages and engine mountings. Three built - (G-EARO, G-EAUF, G-EAWO). DH.18B Plywood-covered fuselage and increased weights. Two built - (G-EAWW and G-EAWX). Operators United Kingdom - Aircraft Transport and Travel - Instone Air Line - Daimler Hire Ltd - Handley Page Transport Netherlands - KLM (Leased) Specifications (DH.18A) (Data from British Civil Aircraft since 1919, Volume 2) General characteristics Crew: One Capacity: 8 passengers Length: 39 ft 0 in (11.89 m) Wingspan: 51 ft 3 in (15.62 m) Height: 13 ft (4.0 m) Wing area: 621 sq ft (57.7 m2) Empty weight: 4,040 lb (1,833 kg) Gross weight: 6,516 lb (2,956 kg) Powerplant: 1 × Napier Lion 12-cylinder water-cooled W-block aircraft piston engine, 450 hp (340 kW) Propellers: 2-bladed wood fixed pitch propeller Performance Maximum speed: 125 mph (201 km/h, 109 kn) Cruise speed: 100 mph (160 km/h, 87 kn) Range: 400 mi (640 km, 350 nmi) Service ceiling: 16,000 ft (4,900 m) Rate of climb: 660 ft/min (3.4 m/s) Related development De Havilland DH.16 De Havilland DH.34 Aircraft of comparable role, configuration, and era BAT FK.26 Martinsyde Buzzard Sopwith Antelope Sopwith Wallaby Vickers Vulcan Westland Limousine DH.18B DH.18A G-EARO of Instone Air Lines De Havilland DH.18 3-view drawing from Flight, 24 March 1921 |