The XC-35 was a development of the Lockheed Model 10 Electra that was designed to meet a 1935 request by the United States Army Air Corps for an aircraft with a pressurized cabin.

[2] The United States Air Corps wanted the aircraft to perform high altitude research and to test the feasibility of a pressurized cabin.

Greene and Younger worked with Lockheed to modify a Model 10 Electra with a new fuselage consisting of a circular cross-section that was able to withstand up to a 10 psi differential.

The lessons learned from the XC-35 played a key role in the development of the Boeing 307 Stratoliner and the B-29 Superfortress which was to be the first mass-produced pressurized aircraft.

[4] In 1943, NACA pilot Herbert H. Hoover flew the XC-35 into thunderstorms to gather data on the effects of severe weather on aircraft in flight.