Autopilot
A system that controls aircraft path without constant human intervention.
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An autopilot is a system that manages an aircraft's flight path without needing constant manual input from a pilot. It doesn't replace the pilot but instead reduces their workload, freeing them to concentrate on broader tasks like tracking the route, checking weather conditions, and monitoring onboard equipment. When installed, an autopilot typically works alongside an autothrottle, which controls engine power.
First autopilots
Early aircraft demanded a pilot's uninterrupted attention for safe operation. As planes could fly for many hours, this constant focus caused severe fatigue. The autopilot was created to take over some of these duties. The first gyroscopic autopilot for aircraft came from the Sperry Corporation in 1912.
It linked a gyroscopic heading indicator and attitude indicator to hydraulically operated elevators and rudders, allowing a plane to fly straight and level on a compass heading without pilot input. Lawrence Sperry, son of inventor Elmer Sperry, proved its reliability at a 1914 Paris aviation safety contest by flying with his hands off the controls in full view of spectators. After the war, Elmer Sperry Jr. and Capt. Shiras continued developing the design, and in 1930 they tested a more compact, reliable version that kept a U.S. Army Air Corps aircraft on a steady heading and altitude for three hours.
That same year, the Royal Aircraft Establishment in the UK introduced a "pilots' assister" autopilot that used a pneumatically spun gyroscope to move the flight controls. Further improvements included better control algorithms and hydraulic servomechanisms. Adding radio-navigation instruments enabled night and bad-weather flying.
In 1947, a U.S. Air Force C-53 made a transatlantic flight, including takeoff and landing, entirely under autopilot control. Bill Lear developed the F-5 automatic pilot and automatic approach control system, winning the Collier Trophy in 1949. The first ship to use an autopilot was the Standard Oil tanker J.A. Moffet in the early 1920s. The Piasecki HUP-2 Retriever was the first production helicopter with an autopilot, and the Apollo program's lunar module digital autopilot was an early fully digital system for spacecraft.
Not all passenger aircraft today have an autopilot.
Quick Facts
- Year of first demonstration
- 1914
- Collier trophy recipient
- Bill Lear
- Year of collier trophy
- 1949
Facts from the source article.
Lore & Background
In the early days of aviation, aircraft required the continuous attention of a pilot to fly safely. As aircraft range increased, allowing flights of many hours, the constant attention led to serious fatigue. The first gyroscopic autopilot for aircraft was developed by Sperry Corporation in 1912, connecting a gyroscopic heading indicator and attitude indicator to hydraulically operated elevators and rudder.
Lawrence Sperry demonstrated it in 1914 at an aviation safety contest in Paris by flying with his hands away from the controls. In 1930, the Royal Aircraft Establishment in the United Kingdom developed an autopilot called a pilots' assister that used a pneumatically spun gyroscope. The autopilot was further developed to include improved control algorithms and hydraulic servomechanisms, and adding radio-navigation aids made night and bad-weather flight possible. In 1947, a U.S. Air Force C-53 made a transatlantic flight, including takeoff and landing, completely under autopilot control.
Bill Lear developed the F-5 automatic pilot and automatic approach control system, receiving the Collier Trophy in 1949. The Piasecki HUP-2 Retriever was the first production helicopter with an autopilot. The lunar module digital autopilot of the Apollo program is an early example of a fully digital autopilot system in spacecraft.
Reader's Guide
Modern autopilots are integral to aviation, with international regulations generally mandating their installation in aircraft with more than twenty seats. They divide flight into phases including taxi, takeoff, climb, cruise, descent, approach, and landing, though taxi and takeoff usually remain under pilot control. An autopilot-controlled approach, landing, and rollout is known as an autoland, typically using an Instrument Landing System (ILS) and certified for low-visibility Category III operations.
The autopilot is often integrated with the aircraft's Flight Management System (FMS). Modern autopilots use computer software to read the aircraft's position and control the flight control system, often incorporating thrust control to optimize airspeed. They typically read position and attitude from an inertial guidance system, which accumulates errors over time; these errors are managed through systems such as the carousel system and resolved with digital signal processing, often a six-dimensional Kalman filter. Radio aids such as DME, DME updates, and GPS may be used to correct position.
Control Wheel Steering (CWS) provides an intermediate option between fully automated and manual flight, where the pilot controls the autopilot through yoke or stick inputs. The hardware of an autopilot is designed with redundancy and reliability as foremost considerations, using triplicated microprocessors and extensive test procedures. Some autopilots use design diversity, running software created by different engineering teams on separate computers, though this is becoming less common due to cost.
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Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Autopilot (CC BY-SA 4.0).
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