Secondary flight controls, such as wing flaps and speed brakes, are usually hydraulically operated and either mechanically or electrically controlled. The design of these flight controls slows the aircraft in flight and provides additional lift and stability. These design features greatly increase the versatility and performance of the aircraft. A flap is a hinged or pivoted section that forms the rear portion of an airfoil used to vary the effective chamber. Wing flaps in their most commonly used form are hinged sections of the trailing edges of a wing.
Flaps extend from the fuselage to the inboard side of the aileron.
Wing flaps are connected to the main wing by various kinds of hinges and slides. The flap system discussed in this section is a representative system. The number of flaps will vary according to the size of the aircraft. The components may have different names, depending on the manufacturer, but the operational theory remains the same. This system consists of a series of six flaps, three on the trailing edge of each wing.