12.56 Aeroplane Aerodynamic Theory

12.56.2 Show how CL varies with use of flaps and control surfaces

The coefficient of lift (CL) is a measure of the lift generated by an aircraft's wings. The CL varies with the use of flaps and control surfaces in the following ways:

1. Flaps: Flaps are used to increase the lift generated by the wings at low speeds, such as during takeoff and landing. By increasing the surface area of the wing, flaps increase the CL of the wing. This allows the aircraft to take off and land at lower speeds, which can improve safety and reduce the length of the runway required.

2. Control surfaces: Control surfaces, such as the ailerons, elevators, and rudder, are used to control the aircraft's attitude and movement through the air. By changing the angle of attack and other aerodynamic factors, control surfaces can increase or decrease the CL of the wing. For example, raising the flaps and lowering the ailerons can increase the CL of the wing, while lowering the flaps and raising the ailerons can decrease the CL of the wing.