Propeller 's blade angle is the angle formed between the face of a propeller blade and its plane of rotation. Blade angle is normally specifies at a particular blade station. ( )
A.the blade angle of propeller is the angle between blade face and rotation plane. B.the blade angle of propeller is the angle between blade face and relative wind C.the blade angle of propeller is always acute angle no matter when the working status of the propeller.正确答案A
