Summary
This notice revises an earlier proposed airworthiness directive (AD), applicable to Honeywell International, Inc.(formerly AlliedSignal Inc. and Garret Turbine Engine Company) high pressure compressor (HPC) impellers installed on TFE731-2, -3, -4, and -5 series turbofan engines. That proposal would have required replacing the HPC impeller with a serviceable impeller that has been eddy-current inspected or with a serviceable impeller of certain part numbers as a terminating action. That proposal was prompted by an incident of an uncontained impeller failure due to cracking in the seal relief area of the HPC impeller. This action revises the proposed rule by eliminating the terminating action and adding those impeller PN's to the suspect impeller population. This action would also clarify certain portions of the proposed AD based on comments that were received from the public. The actions specified by this proposed AD are intended to prevent HPC impeller failure due to fatigue cracking.