What is the primary function of the elevator on an aircraft?

The primary function of the elevator on an aircraft is to control the pitch. Pitch refers to the angle of the aircraft's nose relative to the horizon, which is crucial for managing ascent and descent. When the pilot moves the control yoke or stick forward or backward, the elevator surfaces at the tail of the aircraft deflect up or down.

When the elevator is deflected upward, it creates a downward force on the tail of the aircraft, causing the nose to rise and the aircraft to climb. Conversely, when the elevator is deflected downward, it allows the tail to rise, causing the nose to lower and the aircraft to descend. This control of pitch is vital for maintaining altitude, maneuvering during takeoff and landing, and managing climb rates.

The other functions mentioned, such as controlling the roll and yaw of the aircraft, are managed by other control surfaces like ailerons and rudders, respectively. Additionally, while elevators can influence speed as a byproduct of changes in pitch, controlling speed is not their primary function.