What happens to drag and lift when flaps are extended on an aircraft?

When flaps are extended on an aircraft, both drag and lift increase. This is due to the aerodynamic changes that occur when flaps are deployed.

Flaps increase the curvature of the wing and effectively increase its surface area, which enhances the lift generated at slower airspeeds, especially during takeoff and landing. The increased lift allows the aircraft to operate safely at lower speeds and at steeper angles of attack.

However, this modification to the wing shape also results in a corresponding increase in drag. The increased surface area and altered airflow create more resistance against the aircraft's forward motion, which is characterized as induced drag. As such, when the flaps are extended, the combined effect is an overall increase in both drag and lift, helping to improve the aircraft's performance during critical phases of flight.