Which of the following is considered a secondary flight control?

Flaps are classified as secondary flight controls because they primarily assist in modifying the lift and drag characteristics of an aircraft during different phases of flight. While primary flight controls—such as the elevator, ailerons, and rudder—are essential for basic maneuverability and stability, secondary flight controls like flaps are used to enhance the aircraft's performance, especially during takeoff and landing.

Using flaps allows pilots to achieve greater lift at lower speeds, which is crucial during descent and approach phases. They can be extended or retracted based on flight requirements, modifying the airfoil shape to enhance lift or reduce stall speed. This adaptability makes them a vital tool for safe flight operations, particularly when operating at slower speeds.

In contrast, elevators, ailerons, and rudders are considered primary controls as they directly affect the aircraft’s attitude and direction in three-dimensional space, ensuring immediate responsiveness for maneuvers.