Which of the following is a secondary flight control feature?

• A. Slats/Flaps
• B. Ailerons
• C. Elevator
• D. Rudder

Answer: (A)

Secondary flight controls are devices that optimize performance rather than directly control the aircraft’s attitude in normal flight. The primary controls—ailerons, elevator, and rudder—are used to steer the aircraft: roll, pitch, and yaw. Slats and flaps, on the other hand, alter the wing’s lift characteristics to improve performance during specific phases like takeoff and landing, by increasing lift and delaying stall at lower speeds. They change wing camber and, with flaps, the trailing-edge shape to boost lift and control drag, which helps shorten takeoff runs and keep the airplane well-behaved at low speeds. That’s why slats/flaps are categorized as secondary flight-control features.