AD FAA-2010-0683

We are superseding airworthiness directive (AD) 2011-23-01 for all Technify Motors GmbH (TMG) models TAE 125-01 and TAE 125-02-99 reciprocating engines with certain part number (P/N) and serial number (S/N) clutch assemblies installed. AD 2011-23-01 required replacement of certain P/N and S/N clutch assemblies. This AD requires the same actions but expands the population of affected P/N and S/N clutch assemblies. This AD was prompted by an additional report of a clutch assembly that malfunctioned due to disk springs that received a nonconforming heat treatment process. We are issuing this AD to prevent failure of the clutch assembly, which could lead to failure of the engine, in-flight shutdown, and loss of control of the airplane.