Summary
The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to General Electric (GE) CF6-6 series turbofan engines. This proposal would require a reduction of the cyclic life limit for certain high pressure turbine rotor (HPTR) rear shafts, and would require removing certain HPTR rear shafts from service before exceeding the new, lower cyclic life limit. In addition, the proposal would require removing from service certain HPTR rear shafts that currently exceed, or will exceed, the new, lower cyclic life limit according to the compliance schedule described in this proposal. The actions specified by the proposed AD are intended to prevent cracks in HPTR rear shafts that could result in uncontained engine failure and damage to the airplane.