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AirCo DH.4 Light Day Bomber Biplane Aircraft

The Airco DH.4 was produced in nearly 6,300 examples for the Allies and served as a successful day bomber during World War 1.

 Entry last updated on 6/7/2017; Authored by Staff Writer; Content ¬©

  AirCo DH.4  
Picture of AirCo DH.4 Light Day Bomber Biplane Aircraft

AirCo DH.4 (Eagle VIII)

Service Year: 1917
Type: Light Day Bomber Biplane Aircraft
National Origin: United Kingdom
Manufacturer(s): Aircraft Manufacturing Company Ltd (AirCo) / de Havilland - United Kingdom / Dayton-Wright; Fisher Body - USA
Total Units Built: 6,295

With production numbering over 6,000 total units, the AirCo / de Havilland DH.4 was another one of Geoffrey de Havilland's successful aircraft designs of World War 2 (his legacy would later and forever be solidified through the World War 2-era de Havilland DH.98 "Mosquito" fighter-bomber series). The DH.4 was fielded en mass and proved itself a very viable combat platform so much so that the DH.9 - the planned successor to the DH.4 - never unseated the original DH.4 model series. As such, the Dh.4 enjoyed a lasting aerial legacy, achieving success in war time as a principle frontline daytime bomber of the Allies in World War 1 and, in peacetime, serving roles of aerial surveying and crop dusting well into the 1930s.

The DH.4 was designed to meet a War Office specification for a lightweight daytime bomber. Though primarily appearing with the AirCo name, the DH.4 was produced by a variety of sub-contractors throughout England (1,449 total aircraft) and in the United States. U.S. production alone accounted for 4,846 aircraft. British-produced aircraft were fitted with the Rolls-Royce Eagle engine (Eagle III 250hp early and Eagle VIII 375 hp later) whilst American models primarily featured the more powerful Liberty 12 series of 400 horsepower and operated under the United States Army Air Service (USAAS) banner. Despite the use of the Liberty engine, the American model did not feature any notable performance gains when compared to its British counterpart in action - in fact it actually suffered some.

Picture of the AirCo DH.4 Light Day Bomber Biplane Aircraft
Picture of the AirCo DH.4 Light Day Bomber Biplane Aircraft

The DH.4 series carried its crew of two in tandem with the pilot placed ahead and the gunner/observer in the rear. The positions were quite separated which hindered communication between the two despite even a "speaking tube" being implemented. The DH.9 series would remedy this by placing the pilot and rear gunner cockpits close to together. The pilot managed one or two x 7.7mm Vickers machine guns in fixed, forward-facing mountings while the rear cockpit was fitted with 2 x 7.62mm Lewis machine guns on a trainable Scarff ring mounting. The DH.4 was cleared to carry up to 460lb of external ordnance (2 x 230lb bombs or 4 x 112lb bombs).

First flight of the DH.4 was recorded during August of 1916 and the aircraft went into service in January of the following year with the British. The DH.4 was taken on by the Americans upon their entry into the war in 1917 with the series being used operationally in 1918. Fisher Body and Dayton-Wright accounted for most of the stateside production of DH.4s. U.S. use went beyond that of the Army Air Service for the DH.4 was also taken on in number by its Navy and Marine Corps showcasing the versatility in its design.

The primary British Air Service (Royal Flying Corps) variant became the standard DH.4 day bomber. In the post-war years, the biplane proved popular in civilian circles where many were modified for various roles. The DH.4A featured a two-passenger cabin aft of the pilot in a glazed over position. The DH.4R was a single-seat racing mount outfitted with the Napier Lion engine of 450 horsepower.

The U.S. took the de Havilland design even further and manufactured a slew of variants from the standard DH.4 day bomber. This included revised models, civilian marks, experimental types, reconnaissance platforms, various engine installations, dual-control trainers, long-range models, etc... The final U.S. Army DH.4s were not retired until 1932.

Australia and Belgium both operated the series in civilian markings. Military operators went on to include Canada, Chile, Cuba, Greece, Iran, Mexico, Nicaragua, New Zealand, South Africa, the Soviet Union, Spain, and Turkey. The Soviets managed a locally-produced copy from the Polikarpov brand during the post-war years.

The DH.4 was a related offshoot of the DH.4 and appeared in 1917 with 4,091 ultimately built. These also found widespread use the world over.

Structural (Crew, Dimensions, Weights)

Operating Crew (Typical): 2
Overall Length: 30.68 feet (9.35 meters)
Overall Width: 42.39 feet (12.92 meters)
Overall Height: 10.99 feet (3.35 meters)

Weight (Empty): 2,392 lb (1,085 kg)
Weight (MTOW): 3,479 lb (1,578 kg)

Power / Performance (Engine Type, Top Speed)

Engine Type: 1 x Rolls-Royce Eagle VIII inline engine developing 375 horsepower.

Top Speed: 124 knots (143 mph; 230 kph)
Maximum Range: 416 nautical miles (478 miles; 770 km)
Service Ceiling: 21,998 feet (6,705 meters; 4.17 miles)
Rate-of-Climb: 1,000 feet-per-minute (305 m/min)

Armament / Mission Payload

1 OR 2 x 7.62mm Vickers machine guns (fixed, forward-firing).
2 x 7.62mm Lewis machine guns on trainable mount in rear cockpit.

Maximum External Bomb Load of 460lb.

Global Operators (Customers, Users)

Australia; Belgium; Canada; Chile; Cuba; Greece; Iran; Mexico; Nicaragua; New Zealand; South Africa; Spain; United Kingdom; United States

AirCo DH.4 Variants

DH.4 - Base Series Designationl produced in UK and US.
DH.4A - Civil Passenger Model; seating for two in glazed cabin aft of pilot.
DH.4B - US Air Service model; fitted with Liberty engine; pilot's seat relocated aft of fuel tank and adjacent to rear cockpit.
DH.4 B-1 - Increased Fuel Capacity to 110 US gallons.
DH.4 B-2 - Trainer Variant
DH.4 B-3 - Increased Fuel Capacity to 135 US gallons.
DH.4 B-4 - Civilian Variant
DH.4 B-5 - Experimental Civilian Variant with enclosed cabin area.
DH.4BD - Crop-dusting model based on the DH.4B.
DH.4BG - Specialized variant fitting smoke generators.
DH.4BK - Specialized night flying model.
DH.4BM - Communications Variant; single-seat.
DH.4BM-1 - Dual-control DH.4BM model
DH.4BM-2 - Dual-control DH.4BM model
DH.4BP - Experimental Photo-Reconnaissance Platform.
DH.4BP-1 - Survey Platform
DH.4BS - Developmental Platform fitting a Liberty (supercharged) engine.
DH.4BT - Dual control trainer variant
DH.4BW - Developmental Platform fitting a Wright H engine.
DH.4C - Fitting a Packard engine of 300 horsepower.
DH.4L - Civilian Model
DH.4M - Rebuilt DH.4s utilizing steel tubing for fuselage.
DH.4Amb - Airborne Ambulance
DH.4M-1 (Boeing Model 16) - Post-War Production models; all-new fuselage.
DH.4M-1T - Dual control trainer version of the DH.4M production models.
DH.4M-1K - Target Tug Conversion Models
O2B-1 - US Navy designation of DH.4M-1 models.
O2B-2 - US Navy designation of night-flying/cross-country conversion models.
DH.4M-2 - Atlantic-produced post-war models
LWF J-2 ("Twin DH") - Developmental two-engine, long-range model; fitted with 2 x Hall-Scott-Liberty 6 series engines of 200 horsepower each; 30 examples produced.
DH.4R - Racer Model; single seat; fitted with Napier Lion engine of 450 horsepower.
XCO-7 (Boeing Model 42) - Observation Platform by Boeing with new wings, revised tail fin and split landing gear arrangement.

AirCo DH.4 Images