P-39 Airacobra

Source: Wiki

The Bell P-39 Airacobra was one of the principal American fighter aircraft in service at the start of World War II. Although its mid-engine placement was innovative, the P-39 design was handicapped by the lack of an efficient turbo-supercharger, limiting it to low-altitude work. The P-39 was used with great success by the Soviet Air Force, which scored the highest number of individual kills attributed to any U.S. fighter type. Other important users were the Royal Air Force ("RAF"), Free French and Axis member Italian air forces. The later P-63 improved upon and superseded the P-39

The P-39 was powered by an Allison V-1710 12-cyclinder, liquid-cooled, 1200 hp engine mounted in the middle of the fuselage, just behind the cockpit, and a propeller driven by a shaft passing beneath the pilot's feet under the cockpit floor. The main purpose of this configuration was to free up space for the heavy main armament, a 37 mm M4 cannon firing through the center of the propeller hub for optimum accuracy and stability when firing. In fact, the entire design was made to accommodate this gun. This was unusual because fighters had previously been designed around an engine, not a weapon system. Although devastating when it worked, the M4 had limited ammunition, a low rate of fire, and was prone to jamming.

Arms: 1 37-mm M4 cannon firing through the propeller hub with 30 rounds of high-explosive ammo; 2 - .50 cal machine guns mounted either 1 on each wing or 2 in the cowl; 4 - .30 cal machine guns mounted on the wing. The P-39 could carry up to 500 lbs of bombs externally mounted.

Air Transport Command ferry pilots, including U.S. women pilots of the WASP program, picked up the planes at the Bell factory at Wheatfield, New York, and flew them to Great Falls, Montana and then onward via the Alaska-Siberia Route (ALSIB), through Canada to Alaska where Russian ferry pilots, many of them women, would take delivery of the aircraft at Nome and fly them to the Soviet Union over the Bering Strait.