An autogyro (from Greek αὐτός and γύρος, "self-turning"), or gyroplane, is a class of rotorcraft that uses an unpowered rotor in free autorotation to develop lift.

It was originally named the autogiro by its Spanish inventor and engineer, Juan de la Cierva, in his attempt to create an aircraft that could fly safely at low speeds.

[3][4] The term gyrocopter (derived from helicopter) was used by E. Burke Wilford who developed the Reiseler Kreiser feathering rotor equipped gyroplane in the first half of the twentieth century.

The success of the Autogiro garnered the interest of industrialists and under license from de la Cierva in the 1920s and 1930s, the Pitcairn & Kellett companies made further innovations.

Collective pitch controls are not usually fitted to autogyros but can be found on the Air & Space 18A, McCulloch J-2 and the Westermayer Tragschrauber, and can provide near VTOL performance.

It was developed by Igor Bensen in the decades following World War II, who also founded the Popular Rotorcraft Association (PRA) to help it become more widespread.

De la Cierva was troubled by the stall phenomenon and vowed to develop an aircraft that could fly safely at low airspeeds.

[14] De la Cierva's autogiro used an airplane fuselage with a forward-mounted propeller and engine, an un-powered rotor mounted on a mast, and a horizontal and vertical stabilizer.

United States industrialist Harold Frederick Pitcairn, on learning of the successful flights of the autogyro, visited de la Cierva in Spain.

[7] Subsequently, production of autogyros was licensed to several manufacturers, including the Pitcairn Autogiro Company in the United States and Focke-Wulf of Germany.

The principal advantage of the Zaschka machine is its ability to remain motionless in the air for any length of time and to descend in a vertical line so that a landing could be accomplished on the flat roof of a large house.

In 1932 the Pitcairn-Cierva Autogiro Company of Willow Grove, Pennsylvania, United States solved this problem with a transmission driven by the engine.

In March 1934, this type of autogyro became the first rotorcraft to take off and land on the deck of a ship, when a C.30 performed trials on board the Spanish navy seaplane tender Dédalo off Valencia.

[19] Later that year, during the leftist Asturias revolt in October, an autogyro made a reconnaissance flight for the loyal troops, marking the first military employment of a rotorcraft.

[21] During the Winter War of 1939–1940, the Red Army Air Force used armed Kamov A-7 autogyros to provide fire correction for artillery batteries, carrying out 20 combat flights.

The Avro Rota autogyro, a military version of the Cierva C.30, was used by the Royal Air Force to calibrate coastal radar stations during and after the Battle of Britain.

[24] In World War II, Germany pioneered a very small gyroglider rotor kite, the Focke-Achgelis Fa 330 "Bachstelze" (wagtail), towed by U-boats to provide aerial surveillance.

With the beginning of German invasion in USSR June 1941, the Soviet Air Force organized new courses for training Kamov A-7 aircrew and ground support staff.

[22] The autogyro was resurrected after World War II when Dr. Igor Bensen, a Russian immigrant in the United States, saw a captured German U-boat's Fa 330 gyroglider and was fascinated by its characteristics.

Ken Wallis' designs have been used in various scenarios, including military training, police reconnaissance, and in a search for the Loch Ness Monster, as well as an appearance in the 1967 James Bond movie You Only Live Twice.

Three different autogyro designs have been certified by the Federal Aviation Administration for commercial production: the Umbaugh U-18/Air & Space 18A of 1965, the Avian 2/180 Gyroplane of 1967, and the McCulloch J-2 of 1972.

[citation needed] Bensen's success triggered several other designs, some of them fatally flawed with an offset between the centre of gravity and thrust line, risking a power push-over (PPO or buntover) causing the death of the pilot and giving gyroplanes, in general, a poor reputation – in contrast to de la Cierva's original intention and early statistics.

[26] In 2002, a Groen Brothers Aviation's Hawk 4 provided perimeter patrol for the Winter Olympics and Paralympics in Salt Lake City, Utah.

The project for the interior ministry was to train pilots to control and monitor the approach and takeoff paths of the airports in Erbil, Sulaymaniyah, and Dohuk to prevent terrorist encroachments.

[35][36][37] In 18 months from 2009 to 2010, the German pilot couple Melanie and Andreas Stützfor undertook the first world tour by autogyro, in which they flew several different gyroplane types in Europe, southern Africa, Australia, New Zealand, the United States, and South America.

A certificated autogyro must meet mandated stability and control criteria; in the United States these are outlined in Federal Aviation Regulations Part 27: Airworthiness Standards: Normal Category Rotorcraft.

He made a transcontinental flight in his self-built Little Wing Autogyro "Woodstock" from Kitty Hawk, North Carolina, to San Diego, California, in October 2003, breaking the record set 72 years earlier by Johnny Miller in a Pitcairn PCA-2.

[56][57] On 7 November 2015, the Italian astrophysicist and pilot Donatella Ricci took off with a MagniGyro M16 from the Caposile aerodrome in Venice, aiming to set a new altitude world record.

Norman Surplus, from Larne in Northern Ireland, became the second person to attempt a world circumnavigation by gyroplane/autogyro type aircraft on 22 March 2010, flying a Rotorsport UK MT-03 Autogyro, registered G-YROX.

However, as the flight had been severely stalled and interrupted en-route by lengthy delays it was no longer deemed eligible for setting a first, continuously flown, speed record around the world and so this task was then left to James Ketchell to complete, by setting a first official speed record flight around the world for an Autogyro type aircraft, some three months later.