High lift devices are used primarily during which phase of flight?

• A. Low-speed flight.
• B. High-speed cruise.
• C. Supersonic flight.
• D. During vertical takeoff in helicopters.

Answer: (A)

High lift devices are used to increase lift at lower airspeeds, allowing the wing to generate enough lift during slower flight without needing to fly at high speeds. This is essential for takeoff and landing, when the airplane must operate safely at reduced speeds and with shorter runway lengths. By increasing wing camber (and sometimes effective wing area), these devices raise the lift coefficient so you can achieve the required lift at lower speeds. In high-speed cruise, they stay retracted to minimize drag, because the extra lift isn’t needed and the drag penalty would be costly. They aren’t used for vertical takeoff in helicopters, where rotor lift does the job instead.