What is the primary purpose of the elevator on an airplane?

The primary purpose of the elevator on an airplane is to control pitch. The elevator is a movable control surface located on the horizontal stabilizer at the tail of the aircraft. When the pilot moves the control yoke or stick forward or backward, the elevator deflects up or down, altering the aerodynamic forces acting on the tail.

When the elevator deflects upwards, it increases the angle of attack of the tail, causing the nose of the airplane to pitch down. Conversely, when it deflects downwards, it decreases the angle of attack of the tail, causing the nose to pitch up. This control is crucial for maintaining the desired flight attitude, climbing, descending, or changing the aircraft's angle of attack during flight maneuvers.

Understanding pitch control is vital for effective flight operations. The other options involve different aircraft movements: yaw refers to the rotation about the vertical axis, managed mainly by the rudder; roll concerns the rotation about the longitudinal axis, controlled mainly by the ailerons; and drag involves the aerodynamic resistance experienced by the aircraft, generally influenced by the overall design and speed, not specifically managed by the elevator.