What is done to cause a McCauley propeller to feather?

What is done to cause a McCauley propeller to feather?

• A. Oil is allowed to drain out of the propeller.
• B. Oil is pumped into the propeller.
• C. The blade angle is mechanically rotated.
• D. The propeller is slowed by aerodynamic drag.

Answer: (A)

Feathering a propeller means turning the blades to a high pitch so they present minimal drag in the wind, which helps reduce unneeded resistance if the engine isn't driving the prop. For a McCauley prop, this is accomplished by removing oil from the pitch-change mechanism. When oil pressure is allowed to drain out, springs inside the hub drive the blades toward the feather position. Pumping oil in would instead move toward a lower pitch, and mechanically rotating the blade angle isn’t the normal method for this propeller, while relying on aerodynamic drag isn’t how the feathering action is achieved.

Feathering a propeller means turning the blades to a high pitch so they present minimal drag in the wind, which helps reduce unneeded resistance if the engine isn't driving the prop. For a McCauley prop, this is accomplished by removing oil from the pitch-change mechanism. When oil pressure is allowed to drain out, springs inside the hub drive the blades toward the feather position. Pumping oil in would instead move toward a lower pitch, and mechanically rotating the blade angle isn’t the normal method for this propeller, while relying on aerodynamic drag isn’t how the feathering action is achieved.