Action
Notice of proposed rulemaking (NPRM).
Summary
The FAA proposes to supersede an existing airworthiness directive (AD) for Honeywell International Inc. TPE331-10 and TPE331-11 series turboprop engines. That AD currently requires removing certain first stage turbine disks from service. This proposed AD would require the same actions, and would also require performing fluorescent penetrant inspections (FPI) and eddy current inspections (ECI) on certain first stage turbine disks that have a serial number (S/N) listed in this proposed AD. This proposed AD results from our determination that we need to expand the affected population to include other disks from the same heat lot as the failed first stage turbine disk, and that certain inspections are also required. We are proposing this AD to prevent uncontained failure of the first stage turbine disk and damage to the airplane.