Summary
The FAA proposes to adopt a new airworthiness directive (AD) for General Electric Company (GE) CT58-140-1, CT58-140-2, and T58-GE-5, -10, -100, and -402 series turboshaft engines with certain serial numbers (SNs) of stage 1 compressor disks, part number (P/N) 5001T20P01, installed. This proposed AD would require removing certain stage 1 compressor disks from service before reaching a reduced low-cycle-fatigue (LCF) life limit. This proposed AD results from two reports of low blade tip clearances in the compressor. We are proposing this AD to prevent LCF cracking and failure of the stage 1 compressor disk, an uncontained engine failure, and damage to the helicopter.