Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all General Electric Company (GE) CT7-8A model turboshaft engines. This proposed AD was prompted by the manufacturer revising the airworthiness limitations section (ALS) of the existing engine maintenance manual (EMM) to incorporate reduced life limits for certain stage 1 turbine aft cooling plates, stage 2 turbine forward cooling plates, turbine interstage seals, and stage 4 turbine disks. This proposed AD would require revising the ALS of the existing EMM and the operator's existing approved maintenance or inspection program, as applicable, to incorporate reduced life limits for these parts. The FAA is proposing this AD to address the unsafe condition on these products.