What is the primary purpose of flaps attached to the trailing edge of the wing?

The primary purpose of flaps attached to the trailing edge of the wing is to increase both lift and induced drag for a given angle of attack. Flaps are integral to enhancing aircraft performance during critical phases of flight, such as takeoff and landing. When deployed, they modify the shape of the wing, increasing its camber and thus enhancing the lift generated at lower speeds. This is particularly beneficial when an aircraft needs to operate safely at slow speeds, as during landing.

As flaps increase lift, they also generate additional induced drag, which is the drag that occurs due to the creation of lift. This increase in drag is advantageous because it allows the pilot to achieve a lower airspeed while maintaining controlled flight, supporting a steeper angle of descent during landing without risking stalling. The combination of increased lift and induced drag provided by the flaps makes it easier for the aircraft to fly at lower speeds with better control, improving safety and maneuverability during critical operations.