Summary
The FAA proposes to adopt a new airworthiness directive (AD) that applies to GE CF34-1 and -3 series turbofan engines with No. 5 bearing rotating air seal part number (P/N) 4019T60G01 installed. This proposal would require initial and repetitive checks of the magnetic chip detector indicators, which are located in the lubrication system for the engine bearings, and installation of an improved No. 5 bearing rotating air seal as a terminating action. This proposal is prompted by a report of the failure of a No. 5 bearing rotating air seal that led to a fire in the cavity of the low pressure turbine (LPT), overtemperature of the LPT turbine disk, and excessive turbine disk growth. The FAA is proposing this AD to prevent No.5 bearing rotating air seal failures and possible uncontained engine failures.