The Philadelphia-based Autogyro Corporation of America's Pitcairn AC-35 became a familiar sight both on and over Pennsylvania highways in the mid-1930s. Extensive road and air testing of the Pitcairn was financed by the US Bureau of Air Commerce, who thought it might be employed on Philadelphia's autogiro-operated airborne mail service. The AC-35 was a two-seater with a 135-hp engine mounted behind the cabin driving a pair of propellers on a common shaft up front, while another shaft drove its single rear-mounted road wheel.
Tested between 1936 and 1942, not only was it ingenious, it actually worked quite well, but the Pitcairn AC-35 never went into production. In 1960 Skyway Engineering announced ambitious plans for mass production of a revamped AC-35, but like its predecessor, the project was still-born.