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

The primary function of the elevator on an aircraft is to control pitch, which refers to the angle of the aircraft's nose relative to its horizontal flight path. The elevator is a movable control surface located on the tail of the aircraft, specifically on the horizontal stabilizer. When the pilot moves the control yoke or stick forward or backward, the elevator pivots up or down.

When the elevator moves upward, it increases the angle of attack of the tail, resulting in the nose of the aircraft pitching down. Conversely, when the elevator moves downward, it decreases the angle of attack at the tail, causing the nose to pitch up. This mechanism is crucial for managing the aircraft's ascent and descent during flight, allowing for changes in altitude and maintaining desired flight attitudes.

The other options pertain to different control surfaces or functions. Yaw, controlled by the rudder, affects the aircraft's left or right movement while rolling is managed by ailerons for lateral inclination. Adjusting trim involves fine-tuning the position of control surfaces to relieve pilot workload but is not the primary function of the elevator itself.