AD FAA-2013-0397

We are adopting a new airworthiness directive (AD) for all Rolls-Royce Deutschland Ltd & Co KG (RRD) model Tay 620-15, 650-15, and 651-54 turbofan engines. This AD requires a one-time inspection of the high-pressure (HP) air bleed valve operating mechanism and, depending on findings, corrective action. This AD was prompted by excessive deterioration of the HP air bleed valve operating mechanism, which is influencing the aerodynamic fan flutter margin. This condition, if not corrected, could lead to multiple fan blade failure. We are issuing this AD to prevent multiple fan blade failure, which could result in uncontained engine failure and damage to the airplane.