A-20A 3rd BG
The Air Corps announced a production contract for the A-20 and A-20A on May 20, 1939. This contract, utilizing FY 1939 funds, specified 63 A-20s and 14 A-20As, with an additional 109 A-20As ordered from FY 1940 funds. The primary difference between the two variants was the engines: the A-20 was to be powered by the turbo-supercharged R-2600-7 high-altitude engine, while the A-20A used the two-speed, mechanically supercharged R-2600-3. The A-20A closely matched the RAF’s DB-7B, differing mainly in armament, equipment, and radio installations.
Production Details:
A-20As Production:
- The 123 A-20As were sequenced first in the production line with Douglas serials 2751 to 2873.
- Fourteen FY 1939 A-20As were assigned Air Corps serials 39-721 to 39-734.
- 109 FY 1940 A-20As received serials 40-71 to 40-179.
- The A-20A used Wright R-2600-11 engines and had its first flight on September 6, 1940.
A-20s Production:
- Sixty-three A-20s followed, with Douglas serials 2875 to 2936 and Air Corps serials 39-735 to 39-797.
- The first A-20 test flight occurred on November 11, 1940.
Configuration and Armament:
Both the A-20 and A-20A were configured identically as three-place attack bombers with a pilot, bombardier, and gunner. They differed from the DB-7A by having a redesigned, longer nose section with a diagonal demarcation between the Plexiglas windows and airframe. The airframe was strengthened, with wing-attach forgings made of steel instead of aluminum.
Production methods for the A-20 and British DB-7Bs were more efficient, constructing the fuselage in two longitudinal halves, allowing many interior fittings and systems to be installed before joining the halves.
The armament for both consisted of four fixed and two flexible .30-calibre Browning M-2 machine guns. The fixed guns were mounted in the nose, while the flexible guns were in the dorsal and ventral positions. Although there were reports of aft-firing nacelle guns, no official records confirm their installation on any A-20s.
Engine Installations and Modifications:
- The A-20’s planned engine, the R-2600-7 with a General Electric turbocharger, was intended to boost high-altitude performance. However, the bulky and complicated installation led to cooling issues during test flights.
- The decision to delete the turbocharger in spring 1941 resulted in converting most A-20 production to the P-70 night-fighter with the supercharged R-2600-11 engine.
- Three A-20s were modified into photographic F-3s with the turbocharged R-2600-7 installation.
Camouflage and Operational Use:
- After the first natural-metal finish A-20 was built, subsequent aircraft received the standard Air Corps camouflage of Dark Olive Drab and Neutral Gray, with variations blending Medium Green.
- Many A-20As were delivered to the 3rd Bomb Group (BG) at Savannah, Georgia. Approximately forty A-20As saw action overseas, particularly in the Netherlands East Indies and Australia. Two A-20As were destroyed in the attack on Pearl Harbor on December 7, 1941.
Navy Evaluations:
- One A-20A (s/n 39-725) was diverted to the Navy as a BD-1 for evaluation as a land-based bomber. This aircraft, after testing, was replaced by another on the production line and assigned the same serial number.
Engineering Studies and Proposed Modifications:
- There were proposals for fitting a manned tail-gun position to the A-20, but these were never operationally implemented. Some reports suggest tail guns might have been tested on YF-3s, but no conclusive evidence exists.
In summary, the A-20 and A-20A were integral to the Air Corps’ early war efforts, with substantial overlap in design and production with the RAF’s DB-7B. Despite initial issues with engine installations and cooling, the A-20 series became a versatile and widely used platform in various theaters of World War II.