What does Vfe denote in aircraft performance?

• A. Maximum landing speed
• B. Maximum flap extension speed
• C. Cruise speed
• D. Minimum flap extension speed

Answer: (B)

Vfe is the maximum speed at which you may fly with the flaps extended. Flaps are lowered to increase lift at slower speeds for takeoff and landing, but keeping them down at higher speeds places extra load on the wing and can cause flap struktural stress or flutter. Because of that, a limit is set: you must not exceed this speed whenever the flaps are extended. When the flaps are retracted, you can accelerate beyond Vfe, since the wing isn’t carrying the same flap-induced loads. The other options don’t fit because they refer to different speed concepts (such as speeds used for landing alone, cruise flight, or a nonstandard “minimum flap extension” speed).