AD NUMBER: 2007-23-14
SUBJECT: Airworthiness Directive 2007-23-14 SUMMARY: 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: Recently, a double
in-flight engine shut down incident occurred on a DA42 aircraft
equipped with TAE125-01 engines. The BFU (German Accident
Investigation Body) found the root cause to be a violation of the
Airplane Flight Manual procedures (taking-of fwith an
insufficiently charged main aircraft battery) and momentary low
voltage in the electrical system of the aircraft when retracting
the main landing gear. This has been the subject of Diamond Service
Information (SI) 42-040 and a subsequent EASA Safety Information
Notice, SIN2007-08, issued on 18 April 2007. The TAE125-01 and
TAE125-02-99 engines, approved for installation on the DA42, are
FADEC (Full Authority Digital Engine Control) controlled and are
not totally independent from the aircraft electrical power supply.
A significant drop of the voltage causes simultaneously a reset of
the FADEC on both engines with subsequent feathering of the
propeller blades. In the case of an empty battery this scenario may
be considered as catastrophicat the aircraft level. We are issuing
this AD to require actions to correct the unsafe condition onthese