In a hydromatic full-feathering propeller, which statement describes how the feather cycle indicator behaves when completed?

• A. The propeller stops rotating
• B. The feather button releases from the depressed position after the cycle is complete
• C. A cockpit alert light illuminates
• D. The engine rpm drops

Answer: (B)

During a feather cycle, hydraulic pressure drives the blades to the feathered angle while the button stays depressed. Once the blades are fully feathered, the mechanism releases the button so it pops back to its normal position. This returning action is the clear signal that the cycle is complete. The other options aren’t how the indicator signals completion: the prop may still windmill or the engine RPM won’t inherently indicate cycle completion, and a cockpit alert light isn’t the standard indicator for finishing the feather cycle.