Question

The zero-lift angle of attack is zero if the aerofoil is symmetric.

(a) True

(b) False

This question was posed to me in a national level competition.

The question is from Lift Force in division Aircraft Force Systems and the Equations of Motion of Aircraft Performance

Answer 1

The correct choice is (a) True

To explain I would say: The zero-lift angle of attack is zero if the aerofoil is symmetric. The zero-lift angle of attack is represented by α0. For symmetric airfoil the α0=0. For asymmetric airfoil the α0≠0. In the case of cambered airfoil the value of α0 is negative.