Question

What is meant by minimum unstick speed?

(a) The maximum speed at which the aircraft becomes airborne

(b) The minimum speed at which the aircraft does not becomes airborne

(c) The maximum speed at which the aircraft does not becomes airborne

(d) The minimum speed at which the aircraft becomes airborne

The question was asked in an online interview.

This interesting question is from Take-off Performance topic in portion Take-off and Landing Performance of Aircraft Performance

Answer 1

The correct answer is (d) The minimum speed at which the aircraft becomes airborne

For explanation I would say: The minimum unstick speed is the minimum speed at which the aircraft becomes airborne. This occurs when the over rotation pitches up the aircraft to a geometry limited angle of attack with the tail touching the ground.