Action
Notice of proposed rulemaking (NPRM).
Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2022-11-15, which applies to all Rolls-Royce Deutschland Ltd & Co KG (RRD) Model Trent7000-72 and Trent7000-72C engines. AD 2022-11-15 requires initial and repetitive on-wing borescope inspections (BSIs) of the high-pressure turbine (HPT) blades to detect axial cracking and, depending on the results of the inspections, replacement of the HPT blade set. Since the FAA issued AD 2022-11-15, RRD issued updated service material providing improved instructions for inspection of the HPT blades, removing the reduced life limit for affected HPT blades, and revising the HPT blade limits for axial cracking. This proposed AD would continue to require initial and repetitive on-wing BSIs of the HPT blades to detect axial cracking and, depending on the results of the inspections, replacement of the HPT blade set. This proposed AD would also remove the reduced life limit for affected HPT blades. The FAA is proposing this AD to address the unsafe condition on these products.