Which document specifies the distance for blade-angle measurement?

• A. Aircraft maintenance manual
• B. Propeller maintenance manual
• C. Engine maintenance manual
• D. Pilot's operating handbook

Answer: (B)

The main idea here is to use the document that provides exact procedures, reference points, and distance specifications for measuring the propeller blade angle. Blade-angle measurement is a propeller-specific task, so the source that covers propeller components and their maintenance will include the precise method, including how far from a reference point to position the measuring device.

The propeller maintenance manual is the best source because it focuses on propellers and defines the measurement procedure, the reference geometry, and the required distance from the hub or other marks to ensure an accurate angle reading. Using it ensures the measurement aligns with the manufacturer’s tolerances and safety standards.

The other manuals cover different systems: the aircraft maintenance manual deals with airframe and systems, the engine maintenance manual covers engine components, and the pilot’s operating handbook is about flight operations and does not provide maintenance measurement procedures.