Harold Pitcairn

While Cierva gave us the gyroplane, it was Harold F. Pitcairn from Bryn Athyn, Pennsylvania that truly perfected it. Harold Pitcairn was an heir to the Pittsburgh Plate Glass fortune though his heart and interests were always with aviation from a child. He founded Pitcairn Aviation, Inc. to build fixed wing aircraft. He was engaged in the nascent air mail industry. When his pilots became involved in accidents he shifted his attention to rotary wing aircraft which he felt would provide his pilots with a safer means of transporting the mail. 

Pitcairn, independently of Cierva, was pursuing research and testing of rotary wing concepts. His first rotary wing patent was filed in March 1925. He formed Pitcairn Aeronautics, Inc. in 1926 to pursue rotary wing development. 

When Pitcairn learned of Cierva’s successes with the gyroplane, he embarked on a visit to England in the summer of 1928 to meet Cierva and see for himself the first successful rotary wing aircraft fly. Cierva had established a base of operations for gyroplane development in England. Pitcairn was able to meet Cierva and to fly in the C.8L-II.  

Pitcairn ordered a C.8 from Cierva to be outfitted with an American engine and sent to the United States for evaluation. On December 19, 1928 the C.8 Mk.IV became the first gyroplane to fly in the United States. 

Pitcairn acquired a license from Cierva to manufacture gyroplanes in the United States. This led to the creation of the Pitcairn-Cierva Autogiro Company of America, Inc. a subsidiary of Pitcairn Aviation, Inc. in February, 1929. Its purpose was to license the manufacture of gyroplanes in the U.S. The Pitcairn Aircraft Company was licensed by Pitcairn and Cierva to design and manufacture the first truly American gyroplane.

Pitcairn made the first extended cross country flight by gyroplane in the United States flying from Byrn Aythn, PA to Langley Field, VA on May 13, 1929, using a Cierva gyroplane. This was a trip of more than 500 miles. 

The PCA-1 became the first American gyroplane though it was actually flown for the first time by Cierva himself around October 8, 1929. Pitcairn and Cierva would have a long and close business relationship.

The PCA-1B on June 17, 1930 experienced excessive torsional deflection which caused the rotors to slow down resulting in an emergency landing. Because of this, Pitcairn established strict criteria for adequate torsional rigidity of all future rotor blades they designed and built. Rotor blade technology and the aerodynamics of them was a brand new field of study with lots yet to learn.

Pitcairn’s original factory in Byrn Athyn was destroyed by fire on November 18, 1929. Pitcairn was forced to move his operations to Willow Grove, Pennsylvania where he had previously established an airfield. 

Pitcairn is credited with creating the first acceptable pre-rotator on his PCA-2 prototype in March 1930. Up to this time the rotors had to spin up through prolonged taxiing. They were initially brought to spin by hand or via a rope pulled either by humans, horses or even a car. This procedure was analogous to how a top is brought to a spin. 

The PCA-2 became the first gyroplane to receive a United States Department of Commerce approved type certificate on April 2, 1931. Shortly thereafter, on April 22, 1931 a PCA-2 landed on the south lawn of the White House in Washington, D.C. President Hoover was on hand to present the prestigious Collier Trophy to Pitcairn and his associates. The Collier Trophy is awarded annually for great achievements in aviation that have occurred the previous year.

One thing gyroplanes and airplanes share in common is an inability to fly in icing conditions. In late 1931, a Pitcairn gyroplane crashed due to rotor blade icing. Pitcairn did extensive research into rotor blade icing and issued a warning bulleting to gyroplane owners to land immediately if rotor rpm decreased 10-15 rpm while in icing conditions. 

By the end of 1931 there were about 100 gyroplane pilots. In November, the first gyroplane only private pilot licenses were awarded. One of these went to Pitcairn’s nephew, Harold Pitcairn.

Pitcairn in 1931 embarked on a design study for a twin engine gyroplane, the PCA-4 though it was never produced.

Pitcairn thought big and produced a 4-5 passenger gyroplane, the PA-19. It was certified on June 23, 1933. Only five were ever built. It is considered the largest certified gyroplane ever built even to this day. 

Pitcairn began development of a direct control gyroplane in the Spring of 1933, the PA-22 was simply a testbed. Direct control being manipulating the rotor head for directional control. A production ready direct control gyroplane did not materialize until 1941, the PA-39. The PA-22 was originally envisioned to be roadable, the first true flying car. Several roadable versions were built but the concept was abandoned. Later versions of the PA-22 also incorporated jump takeoff capability starting in 1935.

The PA-24 was the last Pitcairn design to incorporate a fixed rotor spindle. Up to this point directional control was achieved through standard aircraft control surfaces, ailerons and elevator in addition to the rudder.  It received its type certification in May 1933. All subsequent Pitcairn gyroplanes would have a direct control rotor head. 

A Pitcairn PA-22 flown by Pitcairn’s primary test pilot, James Ray demonstrated the feasibility of landing and departing from the Philadelphia Post Office roof on May 25, 1935.

The PA-36 first publicly demonstrated jump takeoffs at Horsham near Philadelphia on July 26, 1940. The PA-22 since November 1935 had made a number of jump takeoffs just not before a public audience. Jump takeoffs require the rotor to be accelerated to above the normal takeoff rotation speed and the rotor blades are then shifted into a high pitch attitude. The gyrocopter leaps off the ground. The rotors are then returned to normal pitch and the gyrocopter begins flying normally sans requiring a takeoff run. Jump takeoffs can attain heights of over 30 feet. 

Pitcairn Autogiro Company changed its name to the Pitcairn-Larsen Autogiro Company in 1940.

A.G.A. Aviation, which took over the activities of the former Pitcairn Autogiro Company, produced the YO-61 (PA-44) for the Army which was a pusher configured gyroplane in the spring of 1943 though it never went into service. This was the end of gyroplane development in the U.S. By this time Pitcairn had built more than a hundred gyroplanes though some were rebuilt from earlier models. 

Harold Pitcairn became quite concerned over the safety of his family after the Lindbergh baby kidnapping and routinely patrolled his house at night. Unfortunately, he accidently shot himself and died on April 24, 1960. At the time he was involved in a major lawsuit against the government for improper use of his patents. His company ultimately won the lawsuit in 1977 for $32 million. 

References: 

Wikipedia

Wings of Tomorrow by Juan de la Cierva

Legacy of Wings by Frank Kingston Smith

Cierva Autogiros by Peter W. Brooks