AD 2015-21-01 80 FR 64314

We are adopting a new airworthiness directive (AD) for all Technify Motors GmbH TAE 125-02 reciprocating engines with a dual mass flywheel installed. This AD requires installation of a start phase monitoring system and associated specified software. This AD was prompted by reports of a gearbox drive shaft breaking during starting or restarting of the engine. We are issuing this AD to prevent overload and failure of the gearbox drive shaft, which could result in failure of the engine, in-flight shutdown, and loss of control of the airplane.