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Douglas Havoc / Boston

The Douglas A-20 Havoc, also known as the DB-7, was a versatile American aircraft used for bombing, reconnaissance, night fighting, and more during World War II.

Originally designed for the French air force, the aircraft was later adopted by the United States Army Air Corps (USAAC) as well.

The French DB-7s were the first to see combat and after the fall of France, the Royal Air Force used them under the name Boston.

The USAAF A-20s saw combat in North Africa starting in 1942.

The aircraft was used by several Allied air forces, including the Soviet Air Forces, the Royal Air Force, and the United States Army Air Forces.

In total, 7,478 aircraft were built, with over a third serving with Soviet units.

It was also used by the air forces of Australia, South Africa, France, and the Netherlands during the war, and by Brazil afterward.

Most British Commonwealth air forces called the bomber variants Boston, while the night fighter and intruder variants were named Havoc, except for the Royal Australian Air Force, which used the name Boston for all variants.

The USAAF referred to the night fighter variants as P-70.

The aircraft was initially designed in 1936 by a team headed by Donald Douglas, Jack Northrop, and Ed Heinemann.

The first design was cancelled due to underpowering, but in 1937, the USAAC issued a new specification for an attack aircraft.

The Douglas team developed the Model 7B, which was eventually chosen by the USAAC.

The French also placed a large order for the aircraft, leading to a redesign with a deeper fuselage and a crew of three.

The revised aircraft, the DB-7, made its first flight in August 1939.

In 1939, the USAAC ordered 186 aircraft under the designations A-20 and A-20A, powered by Wright R-2600 Twin Cyclone engines.

The R-2600 powered aircraft were also popular for export, with France and Britain ordering hundreds of them.
Boston I & II
The Royal Air Force agreed to take up the balance of the French order which was diverted to the UK and the bombers were given the service name “Boston”, with the further designation of “Mark I” or “Mark II” according to the earlier or later engine type.
Havoc Mk I
The Boston was generally considered unsuitable for use by the RAF since its range was too limited for daylight raids on Germany.
Many of the Boston Mk II, plus some re-engineered Mk Is, were converted for nighttime duties, either as intruders with 2,400 lb (1,100 kg) of bombs, or as night fighters with AI Mk. IV radar.
These Havoc Mk I aircraft were found to be underpowered and were replaced by the de Havilland Mosquito.
A total of 181 Boston’s were converted to Havocs.
In interdiction raids, Havoc intruders caused considerable damage to German targets.
Twenty Havocs were converted into “intruder” aircraft, carrying the Long Aerial Mine (LAM), an explosive charge trailed on a long cable in the path of enemy aircraft in the hope of scoring a hit.
Trials conducted with a single Handley Page Harrows dropping LAMs into the stream of German bombers were not successful, and the Havocs were converted back to Mk I intruders.
Havoc I Turbinlite
Havoc I fitted with a 2.7 million candlepower searchlight in the nose; the batteries for it carried in the bomb bay.
A radar operator sat in the after fuselage.
They were unarmed, and they were supposed to illuminate targets for accompanying Hawker Hurricane fighters.
A total of 31 aircraft were converted.
They were made obsolete by high performance fighters that could carry their own radar.
DB-7/Havoc I
Initial French variant, fitted with two 1,000 hp (750 kW) Pratt & Whitney R-1830. Of the 270 DB-7s ordered, 116 were accepted by the French before the armistice.
DB-7A/Havoc II
The French Purchasing Commission made an order for 100 more bombers that would be equipped with 1,600 hp (1,200 kW) Wright R-2600-A5B Twin Cyclone engines, which was the same engine design used by North American Aviation’s B-25 medium bomber.
These planes were called DB-7A by Douglas Aircraft.
However, none of them were delivered before France fell, so they were sent to the UK instead.
They were then transformed into night fighters by adding 12 x 0.303-inch machine guns to their noses and extra fuel tanks.
At higher altitudes, they could reach a top speed of 344 mph (550 km/h). 39 of these planes were briefly used as Turbinlites.
DB-7B/Boston III
In February 1940, the Royal Air Force placed an order for the DB-7B, which was the first batch of this model to be directly ordered.
These planes had the same engine as the DB-7A, but with improved armour protection.
They also had larger fuel tanks, making them suitable for use as light bombers in the RAF.
This batch was initially given the name “Boston,” but since the DB-7s intended for France were used first, the aircraft in this order were called the Boston Mk III.
The Boston III played a significant role in numerous combat missions, including attacks on German warships such as Scharnhorst, Gneisenau, and Prinz Eugen during Operation Cerberus, and the raid on Dieppe during Operation Jubilee.
A total of 300 Boston III planes were produced and delivered, with some of them being converted for use as night fighters.
A variation on the DB-7B/Boston III built for a French government order and featuring French instruments and secondary equipment; of the 480 DB-73s ordered by France, 240 were built by under license by the Boeing Company in Seattle.
None were delivered, due to the fall of France, the DB-73 block was ordered by the RAF, after conversion to the Boston III configuration. Following the German invasion of the Soviet Union, 151 DB-73s were provided to the USSR.
Following the Japanese attack on Pearl Harbour, a further 356 DB-73s were taken up by the USAAF, which transferred 22 to the Royal Australian Air Force (RAAF) for use in the South-west Pacific theatre.
Australian sources usually list these aircraft as DB-7B.
This particular version of the Dutch Indies Air Force was originally meant to be used in the Dutch East Indies.
However, due to the Japanese conquest of the area, the planes were never delivered.
A portion of the order, known as the “lost convoy,” ended up stranded in Australia.
No. 22 Squadron RAAF assembled the first 31 Boston’s at Richmond Airbase in New South Wales, and they were utilised during the campaign against Buna, Gona, and Lae in New Guinea.

The assembly process was made difficult by the fact that the manuals and instrument panels were printed in Dutch.
The remainder of the order was sent to the Soviet Union, which received a total of 3,125 planes from the Douglas DB-7 series.
The original American indifference to the Model 7B was overcome by the improvements made for the French and British, and the United States Army Air Corps ordered two models, the A-20 for high-altitude bombing and the A-20A for low and medium altitude combat.
Both were similar to the DB-7B.
The A-20 was to be fitted with  turbosupercharged Wright R-2600-7 engines, but these were bulky and the prototype suffered cooling problems, so the remainder were completed with the two-stage supercharged R-2600-11, 59 as P-70 fighters and 3 as F-3 reconnaissance aircraft.
One A-20 was evaluated by the U.S. Navy as the BD-1, while the U.S. Marine Corps flew eight as the BD-2.
The U.S. Army ordered 123 A-20As with R-2600-3 engines, and 20 more with the more powerful R-2600-11.
They entered service in the spring of 1941.
The Army liked the A-20A because of its good performance and because it had no adverse handling characteristics. Nine of them were transferred to the RAAF in 1943.

The USAAF used the British name Havoc for the A-20A, while the RAAF referred to them as Bostons.
The A-20B received the first really large order from the Army Air Corps: 999 aircraft.
These resembled the DB-7A rather than the DB-7B, lacking self-sealing fuel tanks, with light armour, and stepped rather than slanted glazing in their noses.
In practice, 665 of these were exported to the Soviet Union, so only about one third of them served with the USAAF.
The A-20C was an attempt to develop a standard, international version of the DB-7/A-20/Boston, produced from 1941.
It reverted to the slanting nose glass, and it had RF-2600-23 engines, self-sealing fuel tanks, and additional protective armour.
These were equipped to carry an external 2,000 lb (910 kg) aerial torpedo.
A total of 948 were built for Britain and the Soviet Union, but many were retained by the USAAF after the Japanese attack on Pearl Harbor.
The Soviet A-20s were often fitted out with turrets of indigenous design.
Proposed lightweight version with R-2600-7 engines and non-self-sealing fuel tanks. Unbuilt.
From February 1943, the A-20G became the most produced series, with a total of 2850 built.
Its nose was solid and contained four 20 mm (.79 in) Hispano cannons as well as two .50 in M2 Browning machine guns.
The cannon were later replaced with more machine guns after the first batch of 250 was produced, due to their less accurate performance.
After 750 aircrafts had been built, an additional power-driven gun turret was fitted with two .50 in machine guns, causing the fuselage to widen by 6 inches (15 cm).
Additionally, the ventral tunnel gun was changed to another .50 in Browning from a .30 in.
The A-20G was powered by two 1,600 hp (1,200 kW) R-2600-23 engines.
These planes were also delivered to the Soviet Union and used in low-level sorties in the New Guinea theatre by the US.
The A-20H was the same as A-20G, continued with the 1,700 hp (1,270 kW) R-2600-29. 412 of these were built.
The takeoff weight was raised to 24,170 lb (10,960 kg).
In 1948, the last surviving A-20H in United States service was redesignated “B-20” with the elimination of the “A for Attack” category and was given the “Z” prefix as being obsolete.
A-20J/Boston IV
The A-20J carried an additional bombardier in an extended acrylic glass nose section.
These were intended to lead bombing formations, with the following standard A-20s dropping their bombs when signalled by the leader.
A total of 450 were built, 169 for the RAF which designated them Boston Mk IV from the summer of 1944 onwards.
A-20K/Boston V
The A-20K (Boston Mk V in RAF parlance) was the final production version of the A-20 series, the same as the A-20J except for R-2600-29s instead of -23s.
In 1940, the USAAC needed long-range fighters and converted 60 A-20s to P-70 night fighters by 1942.
These planes had British AI Mk IV radar and black-painted noses.

They also had four 20mm cannons and an extra fuel tank.
Later variants replaced the cannons with six .50 calibre guns and American centimetric radar.
The P-70s only saw combat with the USAAF in the Pacific and were retired by 1945.
During World War II, the F-3A was developed by converting forty-six A-20J and K models into night-time photographic reconnaissance planes.
The 155th Photo Reconnaissance Squadron, previously known as the 423rd Night Fighter Squadron, used this variant in the European Theatre.
The 155th Squadron was chosen for this role due to their knowledge of night fighter tactics, which could be employed to defend against German aircraft.

The armament was removed from the plane, but the crew of three (pilot, observer, and navigator) remained the same.

After the surrender of Japan in August 1945, the F-3A became the first Allied aircraft to land at Itazuke.
One A-20A was bought in 1940 by the United States Navy for evaluation for use by the United States Marine Corps.
The Navy/Marine Corps did not have any priority on the production lines, so the BD was not put into service.
During the year 1942, eight Army A-20Bs were repurposed for the United States Navy to serve as high-speed target tugs.
Although the aircraft was modified with target-towing equipment, bombs could still be carried, and all armaments were removed, but they retained their designation as BD in the Bomber sequence.
The planes were retired from service in 1946.
An observation/reconnaissance version of the A-20B powered by two 1,700 hp (1,300 kW) R-2600-7 engines.
The original order for 1,489 aircraft was cancelled, and none were built.
47 ft 11+7⁄8 in (14.63 m)
61 ft 3.5 in (18.68 m)
18 ft 1+1⁄2 in (5.52 m)
Wing area
464 sq ft (43.1 m2)
NACA 23018
NACA 23009
Empty weight
16,031 lb (7,272 kg)
Gross weight
24,127 lb (10,944 kg)
Fuel capacity.
400 US gal (330 imp gal; 1,500 L) normal capacity
300 US gal (250 imp gal; 1,100 L) in an optional external tank
676 US gal (563 imp gal; 2,560 L) in four optional auxiliary tanks in the bomb bay.
2 × Wright R-2600-23 Twin Cyclone 14-cylinder air-cooled radial piston engines,
1,600 hp (1,200 kW) each
3-bladed Hamilton-Standard Hydromatic,
11 ft 3 in (3.43 m) diameter constant-speed fully feathering propellers
Maximum speed
317 mph (510 km/h, 275 kn) at 10,700 ft (3,300 m)
325 mph (282 kn; 523 km/h) at 14,500 ft (4,400 m)
Cruise speed
280 mph (450 km/h, 240 kn) at 14,000 ft (4,300 m)
Stall speed
98 mph (158 km/h, 85 kn)
945 mi (1,521 km, 821 nmi)
Ferry range
2,300 mi (3,700 km, 2,000 nmi)
Service ceiling
23,700 ft (7,200 m)
Rate of climb
2,000 ft/min (10 m/s)
Time to altitude
10,000 ft (3,000 m) in 8 minutes 48 seconds
Wing loading
52 lb/sq ft (250 kg/m2)
0.141 hp/lb (0.232 kW/kg)
6 fixed forward-firing 0.5 in (12.7 mm) Browning machine guns in the nose
2 0.5 in (12.7 mm) Browning machine guns in dorsal turret
1 flexible 0.5 in (12.7 mm) Browning machine gun, mounted behind the bomb bay.
4 triple tube t30/m10 rocket launchers
4,000 lb (1,800 kg).

Camouflage and Markings 10 – Douglas Boston Havoc-RAF Northern Europe 1936-1945.
McDonnell Douglas aircraft since 1920: Volume I-René J Francillon.
The Douglas A20 (7A-Boston III)-Profile Publications 202.
 Douglas A-20 Boston-Havoc-
Warpaint 032-Richard Caruana.

San Diego Air and Space Museum Archive.
The National Museum of the U.S. Air Force.

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