Douglas A-20 Havoc

The Douglas A-20 Havoc (company designation DB-7) was an American attack, light bomber, intruder and night fighter aircraft of World War II. It served with several Allied air forces, principally the United States Army Air Forces (USAAF), the Soviet Air Forces (VVS), Soviet Naval Aviation (AVMF) and the Royal Air Force (RAF) of the United Kingdom. Soviet units received more than one in three (2,908 aircraft) of the DB-7s ultimately built. It was also used by the air forces of Australia, South Africa, France, and the Netherlands during the war, and by Brazil afterwards.

In British Commonwealth air forces, bomber/attack variants of the DB-7 were usually known by the service name Boston, while night fighter and intruder variants were usually known as Havoc. An exception to this was the Royal Australian Air Force, which referred to all variants of the DB-7 by the name Boston. The USAAF referred to night fighter variants as P-70.


Douglas A-20 Havoc
Class Aircraft
Type Bomber
Manufacturer Douglas Aircraft Company
Production Period 1939 - 1944
Origin United States of America
Country Name Origin Year
United States of America 1939
Country Name Operational Year Retirement Year
Australia View
Brazil View
Canada View
France View
Netherlands View
Russia (USSR) View
South Africa View
United Kingdom - UK (Great Britain) View
United States of America 1941 1949 View
ManufacturerName Production From Production To Quantity
Douglas Aircraft Company 1939 1944 7478 View

In March 1937, a design team headed by Donald Douglas, Jack Northrop and Ed Heinemann produced a proposal for a light bomber powered by a pair of 450 hp (336 kW) Pratt & Whitney R-985 Wasp Junior radial engines mounted on a high-mounted wing. It was estimated that it could carry a 1,000 lb (454 kg) bomb load at 250 mph (400 km/h). Reports of aircraft performance from the Spanish Civil War indicated that this design would be seriously underpowered, and it was subsequently cancelled.

In the autumn of the same year, the United States Army Air Corps issued its own specification for an attack aircraft. The Douglas team, now headed by Heinemann, took the Model 7A design, upgraded with 1,100 hp (820 kW) Pratt & Whitney R-1830 Twin Wasp engines, and submitted the design as the Model 7B. It faced competition from the North American NA-40, the Stearman X-100 and the Martin 167F. The Model 7B was maneuverable and fast, but did not attract any US orders.

The model did, however, attract the attention of a French Purchasing Commission visiting the United States. The French discreetly participated in the flight trials, so as not to attract criticism from American isolationists. The Air Corps, which controlled the aircraft's development, but had been excluded from negotiations between the French, the Production Division, and the Navy's Bureau of Aeronautics, was directed by the White House on 19 January 1939 to release the DB-7 for assessment in contradiction of its own regulations. The "secret" was revealed when the Model 7B crashed on 23 January while demonstrating single-engine performance. The French were still impressed enough to order 100 production aircraft, with the order increased to 270 when the war began. Sixteen of those had been ordered by Belgium for its Aviation Militaire.

France

The French order called for substantial modifications, resulting in the DB-7 (for Douglas Bomber 7) variant. It had a narrower, deeper fuselage, 1,000 hp (746 kW) Pratt & Whitney R-1830-SC3-G radials, French-built guns, and metric instruments. Midway through the delivery phase, engines were switched to 1,100 hp (820 kW) Pratt & Whitney R-1830-S3C4-G. The French designation was DB-7 B-3 (the B-3 signifying "three-seat bomber").

The DB-7s were shipped in sections to Casablanca for assembly and service in France and French North Africa. When the Germans attacked France and the Low Countries on 10 May 1940, the 64 available DB-7s were deployed against the advancing Germans. Before the armistice they were evacuated to North Africa to avoid capture by German forces. Here, they fell under control of the Vichy government, briefly engaging the Allies during the Operation Torch.

After French forces in North Africa had sided with the Allies, DB-7s were used as trainers and were replaced in front line units by Martin B-26 Marauders. In early 1945, a few DB-7s were moved back to France where they saw action against the remaining isolated German pockets on the western coast.

British Commonwealth

The remainder of the order which was to have been delivered to France was instead taken up by the UK via the British Purchasing Commission. In the course of the war, 24 squadrons operated the Boston. It first entered service with RAF Bomber Command in 1941, equipping No. 88 Squadron. Their first operational use was not until February 1942 against enemy shipping. On 4 July 1942 United States Army Air Force (USAAF) bomber crews, flying RAF Boston aircraft, took part in operations in Europe for the first time attacking enemy airfields in the Netherlands. They replaced the Bristol Blenheims of No. 2 Group RAF for daylight operations against occupied Europe until replaced in turn by de Havilland Mosquitos. Some Havocs were converted to Turbinlite aircraft which replaced the nose position with a powerful searchlight. The Turbinlite aircraft would be brought onto an enemy fighter by ground radar control. The onboard radar operator would then direct the pilot until he could illuminate the enemy. At that point a Hawker Hurricane fighter accompanying the Turbinlite aircraft would make the attack. The Turbinlite squadrons were disbanded in early 1943.

Soviet Union

Through Lend-Lease, Soviet forces received more than two-thirds of version A-20B planes manufactured and a significant portion of versions G and H. The A-20 was the most numerous foreign aircraft in the Soviet bomber inventory. The Soviet Air Force had more A-20s than the USAAF.

They were delivered via the ALSIB (Alaska-Siberia) air ferry route. The aircraft had its baptism of fire at the end of June 1942. The Soviets were dissatisfied with the four .30-calibre Browning machine guns — themselves only capable of firing at a top rate of 600 rounds per minute apiece — and replaced them with the faster-firing, 7.62mm calibre ShKAS, capable of up to an 1800 rounds per minute firing rate apiece. During the summer of 1942, the Bostons flew ultra low-level raids against German convoys heavily protected by flak. Attacks were made from altitudes right down to 33 ft (10 metres) and the air regiments suffered heavy losses. By mid-1943 Soviet pilots were well familiar with the A-20B and A-20C. The general opinion was that the aircraft was overpowered and therefore fast and agile. It could make steep turns with an angle of up to 65°, while the tricycle landing gear facilitated take-off and landings. The type could be flown even by crews with minimal training. The engines were reliable but sensitive to low temperatures, so the Soviet engineers developed special covers for keeping propeller hubs from freezing up.

Some of these aircraft were armed with fixed-forward cannons and found some success in the ground attack role.

By the end of the war, 3,414 A-20s had been delivered to the USSR, 2,771 of which were used by the Soviet Air Force.

Role Light bomber
Night fighter
Manufacturer Douglas
Designer Ed Heinemann
First flight 23 January 1939
Introduction 10 January 1941
Retired (USAF) 1949
Primary users United States Army Air Forces
Soviet Air Force
Royal Air Force
French Air Force
Produced 1939–1944
Number built 7478
Developed into Douglas DC-5


General characteristics

  • Crew: 2-3
  • Length: 47 ft 11 in (14.63 m)
  • Wingspan: 61 ft 4 in (18.69 m)
  • Height: 17 ft 7 in (5.36 m)
  • Wing area: 465 ft² (43.2 m²)
  • Empty weight: 15,051 lb (6,827 kg)
  • Loaded weight: 27,200 lb (12,338 kg)
  • Max. takeoff weight: 27,200lb (12338 kg) (9,215 kg)
  • Powerplant: 2 × Wright R-2600-A5B "Twin Cyclone" radial engines, 1,700 hp (1,268 kW) each

Performance

  • Maximum speed: 339 mph (295 kn, 546 km/h) at 10,000 ft (3,050 m)
  • Range: 1,050 mi (912 nmi, 1,690 km)
  • Service ceiling: 23,700 ft (7,225 m)
  • Rate of climb: 2,000 ft/min (10.2 m/s)

Armament

  • Guns:
    4× fixed 0.303 in (7.7 mm) Browning machine guns in the nose
    2× flexible 0.303 in (7.7 mm) Browning machine guns, mounted dorsally
    1× flexible 0.303 in (7.7 mm) Vickers K machine gun, mounted ventrally
  • Bombs: 2,000 lb (910 kg)

End notes