AD/Thielert/9 Engine Clutch Assembly (Cth)

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/9 Engine - Clutch Assembly 8/2008 TX

Applicability:

Thielert Aircraft Engines (TAE) GmbH TAE125-02-99 (commercial designation Centurion 2.0) engines, except those with clutch Part Number (P/N) 05-7211-K006001 installed.

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 aircraft.

Requirement:

1. Inspect the clutch in accordance with TAE GmbH Service Bulletin (SB) TM TAE 125-1006 P1 or later NAA approved revision.

2.    When a broken disk spring is found during the inspection detailed in Requirement 1of this AD, replace the clutch with a serviceable part

3. Report to TAE any replacement of the clutch in accordance with TAE GmbH SB TM TAE 125-1006 P1 or later NAA approved revision.

Note 2:  EASA Emergency AD 2008-0100-E dated 23 May 2008 refers.

Compliance:

For Requirement 1: Initial inspection at the interval detailed in Table 1 below, and thereafter, repeat the inspection at intervals not to exceed 100 FH (+/- 10 FH)

Table 1.

Flight hours (FH) accumulated on the effective date of this AD since last clutch inspection:

Required Compliance time:

More than 100 FH

Within 10 FH after the effective date of

this AD

Between 50 and 100 FH

At the next scheduled 100 FH

maintenance after the effective date of

this AD

Less than 50 FH

Prior to accumulating 50 FH since the

last clutch inspection, or within 10 FH

after the effective date of this AD,

whichever occurs later

For Requirement 2: Before further flight.

For Requirement 3: Within 7 days after replacement of the clutch.

This Airworthiness Directive becomes effective on 30 May 2008.

Background:

In-flight engine shutdown incidents have been reported on aircraft equipped with TAE125-02-99 engines.  Investigation showed that this was mainly the result of cracked disc springs in the clutch.  This condition, if not corrected, could result in further cases of engine in-flight shutdown and the consequent loss of control of the aircraft.

This AD requires the inspection of the clutch on all affected TAE125-02-99 engines and, in case of a broken disc spring, the replacement of the clutch with a serviceable part.

David Villiers
Delegate of the Civil Aviation Safety Authority

26 May 2008