Editing Aircraft engine controls (section)

==Propeller==
In an aircraft with a '''fixed-pitch propeller''', there is no direct control over the propeller [[rotational speed]], which depends on the [[airspeed]] and loading. Therefore, the pilot has to pay attention to the RPM indicator and adjust the throttle/power lever in order to maintain the desired constant speed of the propeller. For example, when the airspeed reduces and the loading increases (e.g., in a climb), RPM will decrease and the pilot has to increase the throttle/power. When the airspeed increases and the loading decreases (e.g., in a dive), the RPM will increase and the pilot has to decrease the throttle/power in order to prevent RPM from exceeding the operational limits and damaging the motor.

If the aircraft is equipped with '''adjustable-pitch''' or '''constant-speed propeller(s)''':
*'''[[blade pitch|Blade pitch control]]''' - Maximizes the efficiency of the propeller in different operational conditions (i.e., airspeed) by controlling the desired propeller rotational speed. In [[Variable-pitch propeller (aeronautics)|adjustable-pitch propeller]] control system, the pilot has to adjust the propeller pitch angle and thus [[angle of attack]] of the propeller blades (typically with a lever) to achieve the desired propeller rotational speed. The increased pitch (blade angle of attack) increases the load on the engine and therefore slows it down, and vice versa. However, the actual propeller speed remains stable only if operational conditions (e.g., airspeed) do not change, otherwise the pilot has to constantly adjust the pitch to maintain the desired propeller speed. [[Constant-speed propeller]] control system simplifies this for the pilot by introducing a [[propeller governor]], where the lever controls the desired propeller speed instead of the pitch angle. Once the pilot has set the desired propeller speed, the propeller governor maintains that propeller speed by adjusting the pitch of the propeller blades, using the engine's oil pressure to move a hydraulic piston in the propeller hub. Many modern aircraft use single-lever power control (SLPC) system, where on-board computer ([[FADEC]]) automatically manages the propeller speed based on the desired power setting and operational conditions. The output power from the propeller is equal to a product of propeller efficiency and input power from the engine.
*'''Manifold pressure gauge''' - When the engine is running normally, there is a good correlation between the intake manifold pressure and the torque the engine is developing. The input power into the propeller is equal to a product of propeller rotational speed and torque.