Airworthiness Directives; General Electric Company (GE) CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 Turbofan Engines

This amendment adopts a new airworthiness directive (AD), that is applicable to GE CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan engines with No. 5 bearing rotating air seal part number (P/N) 4019T60G01 installed. This amendment requires 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 amendment 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 actions specified by this AD are intended to prevent No.5 bearing rotating air seal failures and possible uncontained engine failures.