The Pitcairn OP-1 (manufacturer designation: PCA-2) was the first rotary-wing aircraft to be seriously evaluated by any of the world's major air forces.

The engine usually drove a standard propeller, on a vertical plane, in front of the aircraft.

The horizontal rotor, while in flight, did not draw energy from the engine but rather generated lift from airspeed.

The only Pitcairn to see operational service did so in Nicaragua with the US Marines, starting in June 1932.

Marine historian Robert Debs Heinl, Jr. recounted the autogyro as being an "exasperating contraption".