Lockheed XC-35

The Lockheed XC-35 is a twin-engine, experimental pressurized airplane. It was the first American aircraft to feature cabin pressurization. It was initially described as a 'supercharged cabin' by the Army. The distinction of the world's first pressurized aircraft goes to the Junkers Ju 49. The XC-35 was a development of the Lockheed Model 10 Electra that was designed per a 1935 request by the United States Army Air Corps for an aircraft with a pressurized cabin.