AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section. Thielert Piston Engines AD/THIELERT/6 Engine Oil System - Catchtank (Sump) 11/2007 Filter Adapter Applicability: Thielert Aircraft Engines TAE125-01 engines all serial numbers (s/n), up to and including s/n 02-01-1018. Note 1: These engines are known to be installed on, but not limited to, Cessna 172 and (Reims-built) F172 series (EASA STC Nr. EASA.A.S.01527); Piper PA-28 series (EASA STC Nr. EASA.A.S.01632), APEX (Robin) DR 400 series (EASA STC Nr. EASA.A.S.01380); and Diamond DA40 and DA42 series aircraft. Requirement: Modify the engine oil system in accordance with Thielert Aircraft Engines TM/SB TAE 125-0016, initial issue dated 19 September 2006 or Revision 1 dated 15 June 2007. Note 2: EASA AD 2007-0232 dated 23 August 2007 refers. Compliance: Within the next 50 flight hours after the effective date of this directive, but not later than 30 November 2007, whichever occurs first after the effective date of this AD. This Airworthiness Directive becomes effective on 25 October 2007. Background: An in-flight engine shutdown incident was reported on an aircraft equipped with a TAE125-01 engine. This was found to be mainly the result of a blockage of the scavenge oil gear pump due to a broken axial bearing of the turbocharger. The broken parts were sucked into the oil pump and caused a seizure. With the pump inoperative, the oil separator overfilled, causing the engine oil to escape via the breather vent line. This caused a loss of oil that resulted in the engine overheating and subsequent shutdown. Thielert, the engine TC holder, has developed a filter adaptor for the Oil Catchtank (Sump) that is designed to prevent foreign objects from entering into the scavenge pump, minimising the chance of such an incident recurring. Charles Lenarcic Delegate of the Civil Aviation Safety Authority 13 September 2007