Airco DH.5

Airco
Industry	Aircraft manufacturing
Founded	1912
Founder	Geoffrey de Havilland
Headquarters	United Kingdom
Products	Aircraft including Airco DH.5

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The Airco DH.5 was a British single-seat biplane fighter aircraft that served during the First World War. Created and produced by the British firm Airco, it was developed under the guidance of designer Geoffrey de Havilland as a successor to the outdated Airco DH.2.

Among the first British fighters to incorporate the advanced Constantinesco gun synchronizer, the DH.5 enabled a forward-firing machine gun to shoot through the propeller with greater speed and reliability than previous mechanical systems. It also featured an unusual "back-stagger" wing arrangement, with the upper wing positioned behind the lower one. By the time it reached operational units, the DH.5 was already outclassed by contemporary fighters, leading to its poor reception by pilots of the Royal Flying Corps (RFC). It was rapidly phased out once sufficient numbers of the Royal Aircraft Factory S.E.5 became available.

Origins

Following his work on the twin-seat Airco DH.4 light bomber, Captain Geoffrey de Havilland began designing a new single-seat fighter intended to replace the aging Airco DH.2. This project was designated as the DH.5. The concept aimed to merge the enhanced performance characteristics of a tractor biplane with the excellent forward visibility typical of a pusher design. The outcome was a compact, single-bay biplane featuring conventional tractor construction but with a distinctive 27 in (690 mm) backward stagger of its wings—placing the lower wing ahead of the upper one. This layout allowed positioning the pilot beneath the wing’s leading edge, providing an unobstructed forward and upward field of vision, which was considered innovative for its time.

The initial prototype underwent testing at Hendon Aerodrome towards the end of 1916. It was equipped with a 110 hp (82 kW) Le Rhône 9Ja rotary engine powering a two-blade propeller. The fuselage had flat sides behind the wings with short fairings flanking the circular engine cowling. At the rear, it tapered into a vertical rudder post supporting a small fin and horn-balanced rudder assembly. Both upper and lower equal-span single-bay wings were fitted with large ailerons, with rubber bungee cords attached to upper ailerons to return them to neutral positions. Early in development, a small hemispherical spinner was added to the prototype. Due to the pilot’s forward seating relative to the centre of gravity, the main fuel tank was located behind the cockpit beneath the oil tank, complemented by an auxiliary gravity-fed fuel tank mounted above and offset to the right on the upper wing.

Into flight

Flight tests revealed that the aircraft suffered from inadequate directional control, prompting the adoption of a larger fin and rudder. Initially, the first prototype was flown without armament. Around the period when the modified tail assembly was fitted, the aircraft was also equipped with weapons in preparation for official evaluations. The prototype's armament consisted of 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 with adjustable elevation during flight. In production models, the gun was mounted in a more conventional fixed position atop the cowl, offset to the left side, aligned with the flight path. Although the DH.5 may have been intended to engage enemy aircraft from below, its comparatively limited operational ceiling relative to contemporary fighters made this tactic impractical.

On 9 December 1916, the DH.5 prototype began service trials at the Central Flying School. Reports from test pilots were generally positive, highlighting its satisfactory stability and control, as well as its suitability for reconnaissance and maneuverability; however, they also noted restricted rearward visibility. While its speed marked a considerable improvement over the DH.2 predecessor, other fighters already surpassed it in performance, particularly in climb rate. The use of an alternative four-bladed propeller during testing may have further diminished its performance.

Production

By the time trials were underway in France, more advanced aircraft such as the Sopwith Camel and Royal Aircraft Factory S.E.5 were nearing operational status. The DH.5's performance was also inferior to that of the earlier Sopwith Pup. Additionally, its armament—consisting of only a single machine gun when most contemporaries carried two—rendered it under-equipped for 1917 combat standards. Nevertheless, on 15 January 1917, production orders were placed for the DH.5 with two initial contracts totaling 400 units. Four manufacturers participated in building the aircraft: Airco (200 units), British Caudron (50 units), Darracq (200 units), and March, Jones & Cribb (100 units).

Before full-scale production commenced, the DH.5 underwent numerous modifications. A revised fuel system was introduced, adding a five-gallon gravity tank above the upper wing alongside a pressurized main tank located directly behind the pilot’s seat. The aircraft’s external appearance changed significantly due to a redesigned fuselage featuring an octagonal cross-section and additional stringer reinforcements near the engine cowling. The rudder’s horn balance was eliminated as part of these alterations. Some of these updates increased manufacturing complexity.

The primary fuselage structure was constructed in two segments joined at a point aligned with the rear wing struts. Plywood was extensively used throughout much of the framework, supplemented by traditional wire-braced wooden box-girders elsewhere. While early DH.5 examples retained rubber bungee return springs on their ailerons, later versions employed pulleys and balance cables instead. One notable advantage of the design was its exceptional structural robustness, demonstrated during destructive testing conducted in April 1917.

Operational history

The deployment of the DH.5 within the Royal Flying Corps (RFC) squadrons experienced significant delays. These setbacks were largely due to Airco prioritizing production of the more successful DH.4, which considerably limited the DH.5's opportunities.^[1] The first DH.5 aircraft reached No. 24 Squadron on 1 May 1917, but subsequent deliveries were slow, resulting in the squadron having only a handful by early June. The aircraft was met with a generally unfavorable reception among squadron personnel, a sentiment echoed by other units.^[2]

Shortly after its introduction, the DH.5 quickly became unpopular within the RFC ranks. Its distinctive and unusual design sparked largely baseless rumors regarding poor handling characteristics.^[2] Additionally, there were reports suggesting that the aircraft entered service despite objections from its own designers.^[3] In reality, although it demonstrated good maneuverability, its performance deteriorated sharply above 10,000 ft (3,000 m), and it lost altitude rapidly during combat engagements.^[4] The placement of the upper wing created a significant blind spot above and behind the pilot—precisely where an enemy fighter would typically launch an attack.^[5]

File:AFC de Havilland DH 5 Scout plane Sept 1917.jpg

DH.5 with the Australian Flying Corps in September 1917

Thanks to its sturdy build, effective low-altitude capabilities, and excellent forward visibility for the pilot, the DH.5 found a valuable role as a ground-attack aircraft. It performed notably during the Battle of Cambrai.^[6] Throughout this engagement, the DH.5 worked alongside Sopwith Camels to provide mobile aerial machine gun support to infantry forces, strafing German trench lines and inflicting substantial casualties on enemy troops. Replacement efforts were already underway by this time, so Cambrai had minimal influence on accelerating its phase-out.^[7]

The DH.5 was initially issued to No. 2 Squadron of the Australian Flying Corps, marking Australia's first fighter squadron. However, it proved inadequate in combat, with enemy twin-seat aircraft frequently able to evade it.^[7] Primarily utilized in ground-attack missions until December 1917, the DH.5 was eventually superseded by the S.E.5a. By then, its withdrawal from the Western Front was nearly complete, with the final squadron replacing their DH.5s with S.E.5as in January 1918.^[8] When allocated to training units, the DH.5 was similarly unpopular and soon disappeared from RFC operational service.^[9] Several retired airframes were repurposed for experimental work involving alternative gun mounts, jettisonable fuel tanks, and plywood coverings.^[10]

No original DH.5 examples have survived to present day; however, a fully functional full-scale replica constructed in the United States by John Shiveley is exhibited at the Aviation Heritage Centre located at Omaka Aerodrome, New Zealand.Template:Fix/category^{[citation needed]}

Military users

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Australian Flying Corps
- No. 2 Squadron AFC (also known as No. 68 Squadron RFC) deployed in France
- No. 6 (Training) Squadron AFC
- No. 7 (Training) Squadron AFC stationed in the United Kingdom.Template:Fix/category^{[citation needed]}

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Royal Flying Corps

Technical specifications

File:CF15 Airco DH.5 ZK-JOQ 050415 01.jpg

Replica of DH.5 ZK-JOQ displayed at the Classic Fighters 2015 airshow in Blenheim, New Zealand

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References

Notes

↑ Bruce 1966, pp. 5-6.
↑ ^2.0 ^2.1 Bruce 1966, p. 6.
↑ Bruce 1966, p. 7.
↑ Cite error: Invalid <ref> tag; no text was provided for refs named Lamberton p.42
↑ Cite error: Invalid <ref> tag; no text was provided for refs named bruce 34
↑ Cite error: Invalid <ref> tag; no text was provided for refs named bruce 12
↑ ^7.0 ^7.1 Bruce 1966, p. 8.
↑ Taylor 1969, p. 339.
↑ Jackson 1962, p. 52.
↑ Bruce 1966, p. 9.