Bell P-39 Airacobra

The Bell P-39 Airacobra was one of the most unusual American fighters of World War II, built around a 37 mm cannon firing through the propeller hub and powered by an Allison engine mounted behind the cockpit. First flown in 1938, it entered service in 1941. The removal of the turbo-supercharger from production aircraft crippled its high-altitude performance, making it a disappointment as an interceptor, but it proved effective at low altitude in ground-attack and fighter roles.

Nearly half of the roughly 9,500 built were supplied to the Soviet Union, where its heavy cannon armament and rugged construction made it a favorite of Red Air Force pilots, several of whom became leading aces flying it. The Airacobra also served with US, British, and other Allied forces in the Pacific, North Africa, and the Mediterranean.