Bombing-up A-20
The DB-7 and A-20 aircraft configurations for carrying bombs and fuel tanks evolved over different series. Initially, the DB-7’s entire center section served as a bomb bay, divided into two compartments by a small bulkhead. French models, such as the DB-7, DB-71, and DB-73, accommodated French bombs in configurations of sixty-four 10kg fragmentation bombs, eight 50kg demolition bombs, or four 100kg demolition bombs.
For the A-20, A-20A, and A-20B models, the bomb bay featured two vertical chemical or fragmentation bomb racks and two horizontal demolition bomb racks in each bay. The vertical racks could hold up to eighty 30lb American fragmentation bombs in removable vertical chutes, positioned high enough to ensure the bombs cleared the lower chute end before entering the airstream. Access to the vertical racks was via hand holes in the upper fuselage skin. The fragmentation bomb chutes needed removal before loading the horizontal racks, and each bay could carry different bomb types independently. The standard bomb load included options like forty 17-30lb fragmentation bombs, thirty-eight 30lb chemical bombs, ten 100lb demolition bombs, four 300lb demolition bombs, two 600lb demolition bombs, or one 1,100lb demolition bomb. Under maximum alternate gross weight, the load could be eighty 30lb chemical or fragmentation bombs, or sixteen 100lb demolition bombs. Bomb shackles were electrically operated from the cockpit or bombardier position, with an interlock switch preventing release if the bomb doors were closed.
The British modifications to the DB-7B eliminated the vertical bomb racks and extended the bomb bay by about 1ft (30cm) to fit standard 500lb British bombs, redesigning the bomb-bay doors and actuators. New bomb shackles were created to hold British bombs, and a 100-gallon (379-liter) removable fuel tank was added to the forward bomb bay. The DB-7B thus carried two 500lb bombs or four 250lb bombs.
These British modifications were adopted by the AAF for the A-20 series, starting with the A-20C. Vertical racks were entirely removed, replaced by increasingly larger fuel tanks, and the bomb bay was configured to carry four demolition bombs using Lockheed racks and Interstate shackles. Later A-20s could carry four 100lb, 300lb, or 500lb bombs. From the A-20G-20-DO onward, two wing racks under each wing could hold one 100lb, 300lb, or 500lb bomb, increasing the maximum bomb capacity to 4,000lb.
The A-20G could also carry a Mark XIII aerial torpedo in the bomb bay, requiring removal of the bomb doors. The torpedo, hoisted into the bomb bay, extended slightly below the aircraft. For torpedo missions, a torpedo director could be installed in the cockpit for the pilot. While the AAF rarely used the A-20 as a torpedo bomber, the Soviets had some success with it in this role.