Airco DH.6

Airco DH.6
Company type	Military training aircraft
Industry	Aviation
Founded	1916
Founder	Geoffrey de Havilland
Products	Military training biplane

The Airco DH.6 was a British military training biplane operated by the Royal Flying Corps throughout the First World War. It earned several nicknames, including "Clutching hand" and "Skyhook," and many units transitioned to civilian use as light aircraft following the war.

Design and development

During a period when outdated combat aircraft were commonly repurposed for training, the DH.6 was intentionally engineered as a dedicated military trainer. Geoffrey de Havilland appears to have focused on two primary objectives in its design. The first was to create an aircraft that was affordable, straightforward to manufacture, and easy to repair—an essential feature given the frequent accidents typical in training environments. Both upper and lower wings were squared and interchangeable, resulting in roundels sometimes positioned unusually. These wings featured pronounced camber and were supported by cables instead of streamlined wires. The initial model lacked any wing stagger. Production versions replaced the prototype’s characteristic curved fin and rudder with square-cut surfaces. The fuselage was constructed as a simple rectangular box without any aerodynamic refinement. Instructor and trainee occupied tandem basketwork seats within a single, austere cockpit, even by contemporary standards. The standard powerplant was the widely available 90 hp (67 kW) RAF 1a engine, familiar to RFC mechanics due to its use in the B.E.2. This engine was installed without a cowling and featured straight, upswept exhaust pipes. When supplies of the RAF 1a engine diminished, alternative powerplants such as the 80 hp (60 kW) Renault engine were installed.

The second design goal emphasized flight safety for both student pilots and instructors. At that time, RFC trainers often referred to their pupils as "Huns," a term usually reserved for German airmen, reflecting the high accident rates in training schools. To enhance safety, instructors could disengage control inputs from students to avoid conflicts during flight. The aircraft’s handling qualities were deliberately chosen to promote safety. De Havilland’s extensive research on aircraft stability and control, conducted during his tenure at the Royal Aircraft Factory, contributed to developing an aircraft that was stable yet intentionally somewhat unstable for training purposes. Consequently, the DH.6 exhibited exceptionally forgiving flight characteristics, capable of maintaining controlled flight at speeds as low as 30 miles per hour (48 km/h) and allowing pilots to execute turns with improper banking without losing control.

However, some critics described the DH.6 as "too safe" for effective pilot training since its gentle response to novice errors did not adequately prepare aviators for more demanding combat aircraft like the Sopwith Camel, which featured challenging handling even by contemporary standards. Due to its limited power, robust construction, and lack of aerodynamic streamlining, the DH.6’s top speed remained notably low.

Wartime production

During the conflict, no fewer than 2,282 DH.6 aircraft were manufactured within the United Kingdom, from total orders approximating 3,000 units. In addition to Airco, production batches were completed by companies such as Grahame-White, Kingsbury Aviation, Harland and Wolff, Morgan, Savages, Ransomes, Sims & Jefferies, and Gloucestershire. A lone DH.6 was assembled in July 1917 by Canadian Aeroplanes Ltd. as a prototype intended for potential mass production if the supply of Curtiss JN-4 (Can) aircraft proved insufficient. This marked the first British-designed plane constructed on Canadian soil. Ultimately, the anticipated shortage of "Canucks" did not occur, resulting in only this single unit being built.

Operational history

In 1917, the training regimen for RFC pilots underwent a much-needed reform. The School of Special Flying at Gosport, Hampshire, was founded by Maj. Robert R. Smith-Barry to transform flight instructors into highly skilled specialists rather than assigning the role to inexperienced pilots who had barely completed their own instruction. Additionally, operational airmen were given periods of respite to recover from combat fatigue. By late 1917, the Avro 504K had become the standard trainer aircraft, rendering the DH.6 largely redundant for training purposes.

Around 300 DH.6s were reassigned to the RNAS at the end of 1917 for use in anti-submarine patrol duties. Although not ideally suited for this mission, the aircraft demonstrated notable seaworthiness, reportedly remaining afloat for up to ten hours following a water landing. Due to its limited power, it was unable to carry both an observer and armaments simultaneously during operations. Most patrols were conducted solo to accommodate a minimal bomb load alongside a lightweight radio system; however, convoy escort flights typically included an observer who communicated with naval vessels using an Aldis lamp. The inherent instability designed into the DH.6 to maintain student alertness proved exhausting during extended maritime patrols. To address this, experimental modifications were introduced in mid-1918 aimed at enhancing stability. These changes involved adding 10 in (25 cm) of back-stagger to wings with reduced chord and camber, along with narrower elevators and rudder surfaces. Aircraft altered in this manner became informally known as "DH 6As."

As of 31 October 1918, approximately 1,050 DH.6s remained listed on the inventory of the RAF.

Nicknames

Numerous RFC and RAF aircraft from this era acquired nicknames—some achieving semi-official recognition like Sopwith's "zoo" designations—and the DH.6 was no exception, attracting several jocular yet disparaging monikers. The nickname "clutching hand" likely stemmed from reactions among novice pilots. Australian aircrew may have coined the term "skyhook" either due to its sluggish speed or possibly because of the distinctive exhaust pipe shape. Other sobriquets included "crab," "clockwork mouse," "flying coffin," and "dung hunter," with the latter two referring to the plywood cockpit's appearance resembling either a coffin or an outdoor latrine.

Postwar and civilian applications

The DH.6 found no role within the postwar Royal Air Force, leading to the sale of remaining units as surplus. By 1919, numerous aircraft transitioned to civilian operators, primarily utilized for recreational "joy rides." Several were shipped overseas to South Africa, while those stationed at Point Cook were sold in Australia, where they remained operational until the late 1930s.

One particular aircraft was sent to New Zealand, joining the Walsh brothers’ New Zealand Flying School and taking its inaugural flight there in February 1920. Unfortunately, it suffered damage during a storm in August of the same year and was never restored.

Beginning in 1921, around 60 units were produced under license in Spain, equipped with Hispano-Suiza 8 engines. These Spanish-built models featured enhanced fuselage designs with distinct cockpits and rounded rudder/fin assemblies inspired by de Havilland’s style. Some of these aircraft were incorporated into the fleets of two Spanish Air Force training institutions.

In 1921, a DH.6 became the first powered airplane owned by a British Scout Troop when it was donated to the 3rd Hampden (Middlesex) Scouts.

Variants

DH.6: Two-seat trainer aircraft.
DH.6A: Adapted version with improved stability for patrol missions.

Operators

Template:ARG – The River Plate Aviation Co. Ltd.
Template:AUS – Australian Flying Corps

No. 5 (Training) Squadron AFC based in the United Kingdom.
No. 7 (Training) Squadron AFC also in the United Kingdom.
Central Flying School AFC located at Point Cook, Victoria.

File:Flag of Greece (1822-1978).svg Greece

Hellenic Naval Air Service

Template:NZL

New Zealand Flying School

File:Flag of Spain (1785–1873, 1875–1931).svg Spain

Spanish Air Force

Template:GBR

Specifications (DH.6)

Template:Aircraft specs

References

Notes

Bibliography

Baker, David. William Avery "Billy" Bishop: The Man and the Aircraft He Flew. London: The Outline Press, 1990. ISBN 978-1871547078.
Boughton, Terence. The Story of the British Light Aeroplane. London: John Murray, 1963. Template:ASIN
Bruce, J.M. British Aeroplanes 1914–18. London: Putnam, 1957. Template:ASIN
Cheesman, E.F. Reconnaissance and Bomber Aircraft of the 1914–1918 War. Letchworth, UK: Harleyford Publications, 1962. Template:ASIN
Jackson, A.J. de Havilland Aircraft since 1909. London: Putnam & Company Ltd., 1987. ISBN 978-0870218965.
Jackson, A.J. de Havilland Aircraft since 1915. London: Putnam & Company Ltd., 1962. Template:ASIN
Jones, H.A. The War In The Air: Being the story of the part played in the Great War by the Royal Air Force: Volume VI. London: Clarendon Press, 1937. ISBN 978-1847342096
Robertson, Bruce. AMC DH6 (Windsock Datafile 103). Berkhamsted, Herts, UK: Albatros Productions, Ltd., 2004. ISBN 978-1902207582.
Taylor, John W.R. "Airco DH.6". Combat Aircraft of the World from 1909 to the Present. New York: G.P. Putnam's Sons, 1969. ISBN 978-0425036334.
Taylor, Michael J.H. Jane's Encyclopedia of Aviation. London: Studio Editions, 1989, p. 45. ISBN 978-0517103166.

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