The Airco D.H.5 was designed in 1916 as a replacement for Geoffrey de Havilland's earlier D.H.2 pusher aircraft, but it was outclassed by its British contemporaries and was most useful as a ground attack aircraft.
In many ways the D.H.5 was a typical tractor biplane fighter of the period, but it did have one obvious unusual feature. In an attempt to improve the pilot's forward vision de Havilland decided to mount the upper wing 27 inches behind the lower wing. This meant that the pilot's cockpit was located just below the leading edge of the upper wing, giving the pilot a superb view forwards and upwards.
Other that this, the D.H.5 was a conventional aircraft for the period, with a wire braced wooden fuselage, covered with cloth for most of its length. Like most de Havilland designs of the period the nose was reinforced with plywood to give extra strength. It had the standard curved de Havilland rudder, although tests with the prototype late in 1916 showed that the original design was too small.
After these early tests the prototype was armed with a single Vickers gun on an unusual mounting. Normally it was synchronized to fire through the propeller, but it could also be moved up by 60 degrees to fire at targets above the aircraft. The modified aircraft began tests at the Central Flying School on 9 December 1916, and was judged to be a success, with good controls and stability. The only flaw mentioned was a poor rear view, caused by the staggered wings.
These tests also revealed that although the D.H.5 was a great improvement on the D.H.2, it was slower and had a worse rate of climb than both the Sopwith Triplane and the new Sopwith Pub. It could out-fly many aircraft at lower altitudes, but even by the start of 1917 that was no longer enough to make it a good fighter aircraft.
Despite this shortcoming, on 15 January 1917 an order was placed for 400 D.H.5s (eventually increased to 550, although not all were completed). The production aircraft was substantially the same as the prototype, although the fuel system was revised and a plywood superstructure gave the fuselage a misleadingly different structure. The gun elevation gear was removed, saving some weight.
No.24 Squadron was the first to receive the D.H.5, starting on 1 May 1917. No. 32 Squadron was second, but the aircraft appeared in small numbers, and it took at least a month for the two squadrons to completely replace their D.H.2s. The new aircraft was not a success. Its unusual appearance meant that it wasn't really trusted by its pilots, and all sorts of rumours began to circulate about the aircraft, including one which claimed it stalled at 80mph, another which claimed that it had been rushed into service against de Havilland's wishes and another which suggested that it was liable to shed its wings. In reality the D.H.5 was a very sturdy aircraft, and was not prone to mechanical failures.
The D.H.5 had a short lifespan as a front-line fighter, but it found a second use as a low level fround attack aircraft. This began on a small scale during the battle of Ypres in 1917, when two D.H.5s were allocated to each division to support the infantry. The good forward visibility and sturdy construction of the D.H.5 helped to make up for its lack of any forward armour, but not enough to prevent high casualty rates. During the battle of Cambrai, when the D.H.5 was used in large numbers as a ground attack aircraft, loss rates sometimes reached as high as 30%!
The D.H.5 was soon phased out. In October 1917 No.41 Squadron replaced it with the S.E.5a, followed by three more squadrons in December, and by the end of January 1918 it had been withdrawn from all front-line squadrons and the surviving aircraft were quietly retired.
Engine: Le Rhône 9J
Wing span: 25ft 8in
Length: 22ft 0in
Height: 9ft 1.5in
Tare Weight: 1,010lb
All-up weight: 1,492lb
Max Speed: 109mph; 102mph at 10,000ft; 89mph at 15,000ft
Service Ceiling: 16,000ft
Endurance: 2.75 hours
Armament: One Vickers Gun
Bomb load: Four 25lb Cooper bombs under fuselage