Summary
The FAA proposes to adopt a new airworthiness directive (AD) for PW models PW2037, PW2037(M), and PW2040 turbofan engines. This proposed AD would require inspecting all high-pressure turbine (HPT) 2nd stage hubs at the next HPT overhaul after the effective date of the proposed AD. The inspections of the hubs include fluorescent penetrant inspection (FPI) for cracks and an optical comparator inspection (OCI) of the blade retention slots to confirm the hubs are within dimensional tolerances before returning them to service. This proposed AD results from an uncontained release of HPT 2nd stage blades and blade retention lugs. We are proposing this AD to detect cracks and remove nonconforming HPT 2nd stage hubs, which could result in an uncontained release of turbine blades and blade retention lugs, and damage to the airplane.