AD/Rotax/22 Amdt 1 Camshaft Hydraulic Tappet Wear (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/ROTAX/22 and issues the following 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.

Rotax Piston Engines

AD/ROTAX/22 Amdt 1 Camshaft Hydraulic Tappet Wear 7/2008

Applicability:

BRP-Rotax GmbH & Co. KG; Bombardier-Rotax GmbH & Co. KG; Bombardier-Rotax GmbH:

Rotax 912 A series engines from serial number (S/N) 4,410.681 to S/N 4,410.712; and

Rotax 912 F series engines from S/N 4,412.912 to S/N 4,412.921; and

Rotax 912 S series engines from S/N 4,923.263 to S/N 4,923.380; and

Rotax 914 F series engines from S/N 4,420.595 to S/N 4,420.637; and

Any S/N engine on which the camshaft and/or the hydraulic valve tappets have been replaced (e.g. during engine repair or general overhaul) after 1 January 2006 up to and including 1 December 2007.

This AD is not applicable to Engines which have hydraulic valve tappets Part Number (P/N) 854.095 installed during production and engines which have (e.g. during engine repair or general overhaul) P/N 881.831 spare part kit installed, which includes hydraulic valve tappet P/N 854.095, are not affected by the requirements of this revised AD.

Engines with P/N 854.095 hydraulic valve tappets installed prior to delivery by
BRP-Rotax can be identified by (minor) modification number references for each specific engine design: 85-05 for 912 A; F50-05 for 912 F; S34-04 for 912 S; and F45-04 for 914 F engines.  These reference numbers are documented in each individual engine Release Certificate.

Note 1:  The installation of these engines was either done by the respective aircraft manufacturer or through modification of the aircraft by Supplemental Type Certificate.

The following S/N engines have already been inspected before first installation or first engine start up according to section 1.5 Compliance (a) of BRP-Rotax
SB-912-051 and SB-914-034 respectively:

Rotax 912 A series from S/N4,410.709 to S/N4,410.712;

Rotax 912 F series from S/N4,412.920 to S/N4,412.921;

Rotax 912 S series from S/N4,923.381 onwards; and

Rotax 914 F series from S/N4,420.633 to S/N4,420.637.

Requirement:

1.    Inspect the magnetic plug in accordance with BRP-Rotax ASB-912-051 or
ASB-914-034, both dated 13 October 2006, or later approved revision as is applicable.

2.    Repeat the inspection as detailed in Requirement 1 of this AD.

3.    If during the inspection detailed in Requirements 1 or 2 of this AD metal parts greater than 3mm are detected as detailed in Figure 1 and 2 of ASB-912-051 or ASB-914-034 both dated 13 October 2006, or later approved revision as is applicable, carry out investigation and rectification of the cause of the defect.

4.    Do not install an engine listed in the applicability section of this AD unless the magnetic plug has been inspected in accordance with the requirements detailed in Requirement 1 of this AD.

Terminating Action

Modification of the engine by installing P/N 881.831 spare part kit, which includes hydraulic valve tappet P/N 854.095, constitutes terminating action for the requirements of this AD.

Note 2:  EASA 2006-0316 R1 dated 13 March 2008 refers. This AD supersedes EASA AD 2006-316-E.

Compliance:

1.    Before further flight after the effective date of this AD, unless previously accomplished.

2.    Remains unchanged as detailed in the original issue of this AD as: Within 5 hours operation after 20 October 2006 (the effective date of the original issue of this AD but not later than 1 March 2007 and thereafter at every oil change.

Note 3:  Previous accomplishment with Requirement 2 of the original issue of this AD is considered acceptable to showing compliance with this AD.

3.    Before further flight.

4.    From the effective date of this AD.

This Amendment becomes effective on 3 July 2008.

Background:

Increased wear of the camshaft/hydraulic valve tappet can occur.  This may lead to improper engine operation, power loss or in-flight engine failure.

The manufacturer has introduced a new hydraulic tappet which does not require the inspections detailed in this AD.  For that reason this amendment limits the requirements to those engines not fitted with P/N 854.095 hydraulic tappets.

James Coyne
Delegate of the Civil Aviation Safety Authority

22 May 2008