The DH.4 was designed by Geoffrey de Havilland as a light two seat combat aircraft, intended to perform both aerial reconnaissance and day bomber missions.
It 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.
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.
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
Soviet D.H.4s were powered by FIAT A.12, Siddley Puma and German Daimler engines.
United States Variants
DH-4
Two-seat day bomber biplane, 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-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-4M
Rebuilt version of DH-4 with steel tube fuselage.
DH-4Amb
Ambulance.
DH-4M-1
Post-war 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
Post-war 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 6 engines and with wingspan of 52 ft 6 in (16.00 m).
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.
Specifications
(Eagle VIII engine)
Crew
Two
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)
Performance
Maximum speed
143 mph (230 km/h, 124 kn) at sea level
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
Forward firing .303 in (7.7 mm) Vickers machine gun
