Summary
We propose to supersede Airworthiness Directive (AD) 2017-11- 06, which applies to all Pratt & Whitney (PW) PW2037, PW2037D, PW2037M, PW2040, PW2040D, PW2043, PW2143, PW2643, and F117-PW-100 turbofan engine models. AD 2017-11-06 requires initial and repetitive on-wing eddy current inspections (ECIs) of affected engines with certain diffuser and high-pressure turbine (HPT) cases installed. AD 2017-11-06 also requires a fluorescent-penetrant inspection (FPI) of the diffuser case rear flange and the HPT case front flange. Since we issued AD 2017-11-06, we learned of designated engineering representative (DER)- approved diffuser case M-flange replacement repairs. This proposed AD would require an on-wing ECI of all diffuser case M-flange replacement repairs. We are proposing this AD to address the unsafe condition on these products.