Gyroscopic autopilot

The gyroscopic autopilot was a type of autopilot system developed primarily for aviation uses in the early 20th century. Since then, the principles of this autopilot has been the basis of many different aircraft control systems, both military and civilian.

The Sperry Corporation developed the original gyroscopic autopilot in 1912. The device was called a “gyroscopic stabilizer apparatus,” and its purpose was to improve stability and control of aircraft. It utilized the inputs from several other instruments to allow an aircraft to automatically maintain a desired compass heading and altitude.

The key feature of the gyroscopic stabilizer apparatus was that it incorporated a gyroscope to regulate the control surfaces of the aircraft.Lawrence Sperry managed to design a smaller and lighter version of a gyroscope, and the device was integrated into an aircraft's hydraulic control system. Using a negative feedback loop, the gyroscope automatically adjusted the control surfaces of an aircraft to maintain straight and level flight.

Lawrence Sperry’s autopilot was first demonstrated in France on June 18, 1914. Sperry was participating in an exhibition in which 57 planes were fitted with new improvements and innovations. Sperry’s aircraft, a Curtiss C-2, was the only one equipped with a gyroscopic stabilizer. Sperry, along with his assistant Emil Cachin, made three passes in front of a grandstand full of spectators and military observers. On his first pass, Sperry engaged the autopilot and flew past the grandstand with his hands held high off of the controls. On the second pass, Cachin climbed out onto the starboard wing seven feet away from the fuselage with Sperry’s hands still off the controls. When the aircraft banked due to the shift in weight, the autopilot immediately stabilized the wings. On his final pass, Sperry climbed out onto the opposite wing, leaving the pilot seat empty. The observers were amazed at the aircraft’s ability to maintain level flight without a pilot manually controlling it. Sperry also gave Joseph Barres, Commandant of the French Army Air Corps, a ride to demonstrate his device’s ability to perform an unassisted takeoff and landing.

Wiley Post became famous after his record setting trip around the world on June 23, 1931. In his aircraft, a Lockheed Vega nicknamed “Winnie Mae,” he managed to travel around the world in eight days 15 hours and 51 minutes. He accomplished this with the help of Harold Gatty, who served as his navigator and copilot. Two years later he set out to beat his previous record by flying around the world by himself. He wanted to prove that one man could accomplish the same trip without a copilot. In order to accomplish this, he equipped the Winnie Mae with a Sperry gyroscope autopilot and a radio direction finder. Although he experienced some problems with the autopilot, he completed the trip in seven days, 18 hours and 49 minutes. The use of the autopilot and radio direction finder is credited for making the task of navigating the aircraft much easier and more efficient. The use of an autopilot reduced the physical and mental demands on Post as he flew around the world.

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