Summary
This supplemental NPRM revises an earlier proposed airworthiness directive (AD), for Honeywell International Inc. TFE731 series turbofan engines with certain second stage low-pressure compressor rotor (LPCR) discs and/or certain third stage LPCR discs installed. That proposed AD would have required removing from service certain second stage LPCR discs and/or certain third stage LPCR discs. That proposed AD resulted from a report of cracks found during a fluorescent penetrant inspection (FPI) of the disc bore. This supplemental NPRM revises the proposed AD to correct a P/N error, to clarify the applicability, and to clarify the instructions in the compliance section. This supplemental proposed AD results from a report of cracks found during an FPI of the disc bore. We are proposing this supplemental proposed AD to prevent an uncontained failure of a second stage LPCR disc and or a third stage LPCR disc due to cracks in the bore, which could result in damage to the airplane.