The advent of the autothrottle has transformed the aviation industry. It allows pilots to easily fine-tune the airplane’s engine power so that they can focus on other in-flight tasks.
Prior to its invention, pilots relied on more complex and laborious control methods, such as mechanical levers. Autothrottle, however, offers a simpler solution that reduces pilots’ workload. So, what is autothrottle, and how does it work exactly?
Overview of Autothrottle
Autothrottle is a control system in airplanes and other types of aircraft that controls fuel flow to the engine or engines. It consists of an electronic or electromechanical lever in the cockpit. When pushed forward, the autothrottle will increase fuel flow to the engine or engines. When pushed back, on the other hand, the autothrottle will decrease fuel flow to the engine or engines.
Why Airplanes Use Autothrottle
With autothrottle, pilots can achieve a desired airspeed. The airspeed of an airplane is heavily influenced by the amount of fuel flowing to the engine or engines. The greater the fuel flow, the stronger the combustion process within the engine, which translates into a faster airspeed. Autothrottle allows pilots to speed up, slow down or maintain the airplane’s current speed by adjusting fuel flow.
How Autothrottle Works
While there are different types of autothrottle systems, most of them use a similar method of operation. Pilots can choose between speed mode and thrust mode. In speed mode, the autothrottle will adjust fuel flow to the engine or engines to achieve a specific airspeed. In thrust mode, engine power is maintained based on the flight phase.
Flight phases include takeoff, climbing, cruising and descent. Thrust mode keeps the engine power consistent during a given flight phase. During takeoff, for example, prevents sudden increases or decreases of engine power while the airplane is taking off.
As the name suggests, autothrottle works automatically. Pilots typically choose from one of the two available modes. The autothrottle system will then move its thrust lever forward or backward. Forward movement will result in increased fuel flow, whereas backward movement will result in decreased fuel flow.
The autothrottle system will make changes as needed. It will use flight data — altitude, current airspeed, etc. — to determine whether more or less fuel is needed. It will then adjust fuel flow to achieve the airspeed or settings set by the pilot. Pilots, however, can override the autothrottle to make manual adjustments if needed as well.
