AD/EC 120/12 Amdt 1 Collective Torque Tube Assembly (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/EC 120/12 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 EC 120 Series Helicopters

AD/EC 120/12 Amdt 1 Collective Torque Tube Assembly 10/2005

Applicability:

Model EC 120 B helicopters (RH or LH pilot configuration), equipped with a RH collective lever-to-torque tube connecting part (identified in following text of this Directive as “connecting part”), part number C671C4101202, C671C4101203, or C671C4101204.

Helicopters with serial number 1383 and subsequent are not affected by this Directive.

Requirement:

1.    In accordance with the instructions described in paragraph 2.B.2 of Eurocopter EC 120 Alert Service Bulletin (ASB) No. 67A014, check:

-   the tightening torque load of the connecting part attachment bolts; and,

-   the connecting part for cracks.

If the tightening torque load of the connecting part attachment bolts is above the set limit (8 Nm) or if a crack is detected in the connecting part, before further flight, replace the affected connecting part in accordance with paragraph 2.B.3.a. and 2.B.3.b. of ASB No. 67A014.

2.    Remove from service, part number C671C4101202, C671C4101203, and C671C4101204 connecting parts.

Accomplishment of Service Bulletin No. 67-017 constitutes terminating action for the requirements of this Directive.

Note:  DGAC AD F-2005-086 refers.

Compliance:

1.    Within 10 flight hours after 3 March 2004.

2.    Before 1 May 2006.

The compliance time for Requirement 1 remains unchanged by this issue.

This Amendment becomes effective on 29 September 2005.

Background:

The manufacturer received a report of failure of the right hand collective lever-to-torque tube connecting part, which was detected on the ground, with the rotor stopped.

Amendment 1 is issued in response to new DGAC AD, which introduces an alert service bulletin to replace the alert telex of the same number, extends applicability to an additional part number connecting part, introduces optional terminating action, and requires the removal from service of the affected collective lever-to-torque tube connecting parts.

David Villiers
Delegate of the Civil Aviation Safety Authority

9 August 2005