The Lockheed P-38 was primarily designed to be an Interceptor aircraft, but it was also used as a fighter-bomber and a long-range escort fighter. Like Boeing, Consolidated, Curtiss, Douglas and Vultee, Lockheed was contracted to take part at a requirement of the United States Army Air Corps (USAAC) for a twin-engine interceptor aircraft
The new fighter aircraft had to meet the following criteria:
- 580 km/h in a ceiling of 6,000 m
- A maximum speed of 466 km/h at sea level
- It must be able to hold an altitude of 6,000 m for at least one hour at full throttle
- 670 m after take-off it must be able to fly over an 15 m high obstacle
Hall Hibbard und Clarence “Kelly“ Johnson recommended the USAAC the model “22-64-01“, the design by Lockheed had three fuselages and was criticized, because of it’s unconventional design. However it was chosen on 23rdJune 1937.
It was powered by two Allison V-1710 engines with a power of 857 kW (1,150 horsepower) each. To balance the Torque of the propellers, they rotated asymmetrical. The central fuselage with the cockpit is equipped with a 20 mm Hispano-Suiza HS.404 gun and four 12.7 mm Browning M2 machine guns.