Fixed-pitch propellers are designed as climb propellers, cruise propellers, or standard propellers. Which of the following is NOT a design category?

• A. Feathered propellers
• B. Climb propellers
• C. Cruise propellers
• D. Standard propellers

Answer: (A)

Fixed-pitch propellers have a single blade angle chosen to suit a general operating range, with climb, cruise, and standard referring to that fixed setting optimized for different flight goals. Feathering, however, is a capability of propellers with adjustable pitch, where the blades are rotated to a high pitch to minimize drag—something that fixed-pitch props cannot do in flight. Because feathering requires blade-angle changes, it isn’t a design category for fixed-pitch propellers. Thus, feathered propellers are the option that doesn’t fit.