The Airco DH.5 was a British First World War single-seat biplane fighter aircraft.
Development was led by the aircraft designer Geoffrey de Havilland as a replacement for the obsolete Airco DH.2.
The DH.5 was one of the first British fighter designs to include the improved Constantinescu gun synchronizer, which allowed a forward firing machine gun to fire through the propeller faster and more reliably than the older mechanical gears.
It was also one of the earliest biplanes to feature a marked back-stagger of its wings.
Despite these advances, by the time the DH.5 was fielded, it was already notably inferior to other fighters that had entered into production and thus proved to be both unpopular and unsatisfactory amongst the pilots of the Royal Flying Corps (RFC).
Nevertheless, on 15 January 1917, the DH.5 was ordered in quantity production in the form of two contracts for a combined 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).
22 ft 0 in (6.71 m)
25 ft 8 in (7.82 m)
9 ft 1 1⁄2 in (2.781 m)
212.1 sq ft (19.70 m2)
1,010 lb (458 kg)
1,492 lb (677 kg)
26 imp gal (31 US gal; 120 L)
1 × Le Rhône 9J, nine cylinder rotary engine,
110 hp (82 kW)
2-bladed, 8 ft 6 in (2.59 m) diameter
102 mph (164 km/h, 89 kn) at 10,000 ft (3,050 m)
2 hr 45 min
16,000 ft (4,900 m)
Time to altitude
12 min 25 s to 10,000 ft (3,050 m)
27 min 30 s to 15,000 ft (4,570 m)
1 × 0.303 in (7.7 mm) Vickers machine gun
Racks for four 25 lb (10 kg) bombs under fuselage.