Action
Final rule.
Summary
We are superseding airworthiness directive (AD) 2006-18-14 for all Rolls-Royce Deutschland Ltd & Co KG (RRD) Tay 650-15 and Tay 651-54 turbofan engines. AD 2006-18-14 required calculating and re- establishing the cyclic life of stage 1 high-pressure turbine (HPT) disks, part number (P/N) JR32013 and P/N JR33838, and stage 1 low- pressure turbine (LPT) disk, P/N JR32318A. In addition, this AD requires re-calculating the cyclic life, and would impose a reduced cyclic life of stage 1 HPT disk, P/N JR32013. This AD was prompted by RRD review of the cyclic life limit of parts affected by AD 2006-18-14 and the RRD conclusion that the stage 1 HPT disk, P/N JR32013, requires further cyclic life limit reduction. We are issuing this AD to prevent failure of stage 1 HPT disks, P/N JR32013 and P/N JR33838, and stage 1 LPT disk, P/N JR32318A, uncontained disk release and damage to the airplane.