Summary
The FAA proposes to adopt a new airworthiness directive (AD) for Pratt & Whitney Canada (PWC) models PW123, PW123B, PW123C, PW123D, PW123E, PW123AF, PW124B, PW125B, PW126A, PW127, PW127E, PW127F, and PW127G turboprop engines. This proposed AD would require initial and repetitive gap inspections of the bypass valve cover, on certain part number (P/N) mechanical fuel controls (MFCs), and replacement of those MFCs as mandatory terminating action to the repetitive inspections. This proposed AD is prompted by sixteen reports of loss of engine throttle response and overspeed, eight of which resulted in in-flight shutdown. We are proposing this AD to prevent loss of throttle response and overspeed, resulting in engine in-flight shutdown.