Action
Notice of proposed rulemaking (NPRM), DOT.
Summary
We propose to adopt a new airworthiness directive (AD) for Hamilton Sundstrand Corporation 14SF-7, 14SF-15, and 14SF-23 series propellers using certain Hamilton Sundstrand Corporation auxiliary pumps and motors (auxiliary feathering pumps). This proposed AD was prompted by a report of a propeller not moving into the feathering position after an engine in-flight shutdown. This proposed AD would require removing certain serial numbers (S/Ns) of auxiliary feathering pumps from service. We are proposing this AD to prevent propellers from failing to move into the feathering position after an engine in-flight shutdown. Propellers failing to feather can cause high drag on the propeller, asymmetric thrust, and difficulty of, or impossibility in, controlling the airplane.