We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
Service experience has shown that a case of FADEC channel B manifold air pressure (MAP) sensor hose permeability is not always recognized as fault by the FADEC. The MAP value measured by the sensor may be lower than the actual pressure value in the engine manifold, and limits the amount of fuel injected into the combustion chamber and thus the available power of the engine. A change in FADEC software version 2.91 will change the logic in failure detection and in switching to channel B (no automatic switch to channel B if MAP difference between channel A and B is detected and lower MAP is at channel B).
In addition, previous software versions allow–under certain conditions and on DA 42 aircraft only–the initiation of a FADEC self test during flight that causes an engine in-flight shutdown.
We are issuing this AD to prevent engine in-flight shutdown or power loss, possibly resulting in reduced control of the airplane.
FAA-2010-0820 Thielert Aircraft Engines GmbH Models TAE 125-01, TAE 125-02-99, and TAE 125-02-114 Reciprocating Engines
By John Bagnas
