AD/Dauphin/83 Amdt 2 Tail Rotor Gearbox Oil Level and Pitch Control Rod Bearing (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/DAUPHIN/83 Amdt 1 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.

Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters

AD/DAUPHIN/83 Amdt 2 Tail Rotor Gearbox Oil Level and Pitch Control Rod Bearing 10/2008 DM

Applicability:

SA 365 N1, AS 365 N2 and AS 365 N3 helicopters.

Requirement:

1.    Check the Tail Gear Box (TGB) oil level in accordance with paragraph 2.B.1. of EUROCOPTER AS 365 Alert Service Bulletin (ASB) No. 05.00.54 Revision 1 or later DGAC approved revisions.

2.    Check for play in the double bearing of the TGB control rod/shaft assembly in accordance with paragraph 2.B.3 of EUROCOPTER AS 365 ASB No. 05.00.54 Revision 1 or later DGAC approved revisions.

3.    If play is detected, accomplish the corrective actions in accordance with paragraph 2.B.3.b) of EUROCOPTER AS 365 ASB No. 05.00.54 Revision 1 or later DGAC approved revisions.

4.    Report the results to Eurocopter in accordance with EUROCOPTER AS 365 ASB No. 05.00.54 Revision 1 or later DGAC approved revisions.

5.    Carry out a check of the TGB to ensure that there are no chips at the magnetic plug, in accordance with paragraph 2.B.2 of EUROCOPTER AS 365 ASB No. 05.00.54 or later DGAC approved revisions. If there are no chips detected, resume flights.

6.    If there are chips detected, accomplish the corrective actions detailed in paragraph 2.B.2.b of EUROCOPTER AS 365 ASB No. 05.00.54 Revision 1 or later DGAC approved revisions.

Note:  EASA AD 2008-0147-E dated 1 August 2008 refers.  This AD supersedes EASA AD 2006-0258R1-E dated 29 August 2006.

Compliance:

For Requirement 1 - Within 10 Flight Hours (FH) after the effective date of this AD and thereafter at intervals not to exceed 10 FH.

For Requirement 2 - Within 50 FH after the effective date of this AD and thereafter at intervals not to exceed 110 FH.

For Requirement 3 - Before further flight after the effective date of this AD.

For Requirement 4 - Within 10 days after each check is completed as detailed in Requirement 2 of this AD, when play is detected in the double bearing.

For Requirement 5 - For TGBs not equipped with a magnetic plug with electrical indicating, at the latest at the next scheduled check of the magnetic plug following the effective date of this AD and thereafter at intervals not to exceed 25 FH.

For TGBs equipped with a magnetic plug with electrical indicating, at the next scheduled check of the magnetic plug, or after illumination of the TGB “CHIP” warning light, whichever occurs first, following the effective date of this AD, and thereafter upon each illumination of the TGB “CHIP” warning light.

For Requirement 6 - Before further flight after the effective date of this AD.

This Amendment becomes effective on 11 August 2008.

Background:

This AD was in response to an event where tail rotor pitch control loss occurred during the landing phase of the helicopter.  Failure of the pitch control rod bearing can lead to loss of control of the tail rotor and subsequent loss of control of the helicopter.

Amendment 1 introduced the following actions:

-    maintaining TGG oil level at the maximum level,

-   checking of axial play in the tail rotor pitch control rod bearing, in case of metallic particle(s) detected at the TGB magnetic plug.

Amendment 2 revises the inspection schedule for the axial play in the tail rotor pitch bearing.

The original issue of this AD became effective on 27 February 2006.

Amendment 1 of this AD became effective on 23 November 2006.

James Coyne
Delegate of the Civil Aviation Safety Authority

5 August 2008