An autogyro, or gyroplane, is a class of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. While similar to a helicopter rotor in appearance, the autogyro's unpowered rotor disc must have air flowing upward across it to make it rotate.
The Buhl Aircraft Company was a US aircraft manufacturer founded in Detroit in 1925 which remained in operation until 1933. Buhl designed and manufactured the Buhl-Verville CA-3 Airster, the first aircraft to receive a US civil aviation type Certificate in March 1927. Several utility and sport aircraft models were developed from 1925 to 1931, both fixed wings and rotary wing aircraft. Their greatest successes were with the Airsedan and Bull Pup, with approximately 185 aircraft of all types built from 1925 to 1932.
The Pitcairn Mailwing family was a series of American mail carrier and three-seat sport utility biplane aircraft produced from 1927 to 1931.
The Pitcairn OP-1 was the first rotary-wing aircraft to be seriously evaluated by any of the world's major air forces. The machine was not a helicopter, nor an airplane, but an autogyro. Pitcairn's model was never put into production for any military.
Harold Frederick Pitcairn was an American aviation inventor and pioneer. He played a key role in the development of the autogyro and founded the Autogiro Company of America. He patented a number of innovations relating to rotary wing aircraft.
The Cierva C.8 was an experimental autogyro built by Juan de la Cierva in England in 1926 in association with Avro. Like Cierva's earlier autogyros, the C.8s were based on existing fixed-wing aircraft fuselages – in this case, the Avro 552.
The Kellett KD-1 was a 1930s American autogyro built by the Kellett Autogiro Company. It had the distinction of being the first practical rotary-wing aircraft used by the United States Army and inaugurated the first scheduled air-mail service using a rotary-wing aircraft.
The Kellett Autogiro Corporation was an American aircraft manufacturer from 1929 based in Philadelphia, named after founder W. Wallace Kellett.
The Bensen B-7 was a small rotor kite developed by Igor Bensen in the United States in the 1950s and marketed for home building. It was a refined to be a slightly larger version of the B-6, replacing the skids with a tricycle undercarriage, and adding a single large fin to the rear of the aircraft.
The Kellett K-2 was a two-seat autogyro developed in the United States in the early 1930s. Later examples were designated K-3 and K-4 when equipped with more powerful engines. K-3 NC 12691 is seen in the 1934 movie, It Happened One Night.
The Kellett XR-8 was a helicopter built in the United States during World War II. It was a two-seat machine intended to demonstrate the feasibility of a twin-rotor system and, while it accomplished this, it also demonstrated a number of problems that prevented further development of this particular design.
The Pitcairn PA-34 and Pitcairn PA-33, given the United States Navy (USN) designation Pitcairn OP-2 and United States Army designation Pitcairn YG-2 respectively were reconnaissance autogyros designed and built in 1936 for evaluation.
The Pitcairn PAA-1 was an autogyro developed in the United States in the early 1930s. Of similar configuration to Pitcairn's earlier machines, the PAA-1 had an airplane-like fuselage with two open cockpits in tandem and a tractor-mounted engine in the nose. It was also equipped with small wings, which carried control surfaces, rather than using the rotor for flight control. It was a smaller and lighter machine than its predecessors and was designed specifically with private pilots in mind.
The Pitcairn PA-18 was an autogyro produced in the United States in the early 1930s.
The Pitcairn PA-19 was a four-seat autogyro developed in the United States in the early 1930s. While most of Pitcairn's autogyro designs featured open cockpits in tandem, the PA-19 had a fully enclosed cabin. It also had wings that carried control surfaces. The rotor provided lift only, but could be tilted in flight to trim the aircraft. Four examples were built before the effects of the Great Depression forced Pitcairn to abandon autogyro production in 1934.
The Pitcairn PCA-2 was an autogyro developed in the United States in the early 1930s. It was Harold F. Pitcairn's first autogyro design to be sold in quantity. It had a conventional design for its day – an airplane-like fuselage with two open cockpits in tandem, and an engine mounted tractor-fashion in the nose. The lift by the four-blade main rotor was augmented by stubby, low-set monoplane wings that also carried the control surfaces. The wingtips featured considerable dihedral that acted as winglets for added stability.
The Autogiro Company of America AC-35 was an early attempt to make a roadable aircraft in the United States during the 1930s. Although it was successfully tested, it did not enter production; a 1960s attempt to revive the aircraft in a non-roadable version also failed to achieve success.
The Pitcairn Aircraft Company was an American aircraft manufacturer of light utility aircraft. An early proponent of the autogyro, the company, later known as the Autogiro Company of America among other names, remained in business until 1948.
John MacDonald Miller was a barnstorming pilot, the first person to make a US transcontinental flight in a rotorcraft, the first to land a rotorcraft on the roof of a building, and the first to fly a scheduled US mail rotorcraft service. He was also a test pilot and airline captain. He became the oldest active pilot in the US, making his first flight on his 18th birthday and ending at the age of 101. He died aged 102.
The 1933 experimental Pitcairn PA-22 was one of the first wingless autogyros. It was controlled by movement of the rotor plane rather than the usual control surfaces, though initially the much modified lone example retained rudders as a precaution.
