Flaps are high lift devices attached to the leading or trailing edge of a wing. They help to increase the value of CL and the Stall Angle during the take-off phase of an aircraft. Stall Angle is the angle between the chord line of an airfoil and the undisturbed relative airflow at which stalling occurs where stalling refers to the condition when there is a sudden reduction in the lift generated by the wing. If the stalling angle is higher compared to plain airfoils it allows the aircraft to take off at lower speeds and hence it can even take off from shorter runways. Flaps when fully extended during the landing phase of an aircraft tend to increase the drag so that the aircraft can land on the runway with a safe speed depending upon the shape, size and weight of the aircraft.
Last date updated on July, 2014