Throttle Throttle
The throttle is the control with which the pilot controls the engine's power output. In tandem seating airplanes it is located on the left side of the cockpit along with other primary engine controls, and in side by side seating airplanes it is centrally located on the lower portion of the instrument panel. On some airplanes all the engine controls (throttle, mixture, and propeller) are installed on a separate unit called "engine control quadrant." By means of linkage the throttle is connected to the carburetor (or fuel control unit in fuel injection engines) to regulate the amount of fuel/air mixture supplied to the engine, thereby controlling the power developed (Fig. 4-10).

The power output (and the engine RPM in the case of fixed pitch propeller airplanes) is increased by pushing the throttle forward and decreased by pulling it aft. Unlike an automobile accelerator or gas pedal, the airplane's throttle has no spring return and will remain in any position to which it is set by the pilot. Undesired "creeping" can be prevented 

by means of a friction lock. Movement of the throttle should always be smooth, though positive, to ensure adequate and correct engine response when a change in power is needed. Rough or abrupt throttle usage may result in a delayed engine response or a complete loss of power, as well as in the possibility of exceeding the engine's limitations. Initial throttle movement should be made slowly, then followed by an increase in the rate of throttle movement as the engine responds. There is no situation that will be improved by rough or abrupt throttle usage, even when necessity requires quick changes in power.