Attended the Curtiss Flying School at Newport News, Virginia, and later graduated from the Army Air Cadet School in 1918.
Experimented with helicopters where he and Agnew Larsen developed a flying model with 42-inch diameter rotor blades and carbon dioxide jets on the rotor tips.
Designed the PA-2 Sesqui-Wing Racer, the second Pitcairn design, which won the 1926 National Air Races in two classes.
Designed and built the PA-5 after the United States government announced plans to contract with private operators to carry air mail. The aircraft could carry 600 pounds of mail and had the speed and cruising radius to fly mail out of Atlanta at the close of the business day and arrive in New York for first mail delivery the next morning. Pitcairn won this contract and later bid for and won the Atlanta-Miami contract allowing him to hold most airmail routes on the East Coast.
Formed the Pitcairn-Cierva Autogyro Company of America in 1929 to license the manufacture of Autogyros in the United States under the de la Cierva patents.
Awarded the Collier Trophy for his autogiro development and application in 1930.