Airworthiness Directives; AlliedSignal Inc. TFE731 Series Turbofan Engines

This amendment adopts a new airworthiness directive (AD), applicable to AlliedSignal Inc. TFE731 series turbofan engines, that requires removal from service of certain first stage low pressure turbine (LPT) seal plates prior to accumulating the new, reduced cyclic life limit, and replacement with serviceable LPT seal plates. This amendment is prompted by a report that the machined LPT seal plate geometry did not meet the design intent due to drawing ambiguity. The actions specified by this AD are intended to prevent fatigue cracking and subsequent uncontained failure of an LPT seal plate.