Summary
We propose to supersede airworthiness directive (AD) 2006-18- 14 that applies to all Rolls-Royce Deutschland Ltd & Co KG (RRD) Tay 650-15 and Tay 651-54 turbofan engines. AD 2006-18-14 requires 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. This proposed AD would require re-calculating the cyclic life, and would impose a reduced cyclic life, of stage 1 HPT disk, P/N JR32013. We are proposing 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, which could result in an uncontained engine failure and damage to the airplane.