AD/AS 355/57 Amdt 1 - Tail Rotor Hub Pitch Change Bearings (Cth)

AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AS 355/57 and issues the following AD under subregulation 39.1 (1) of CAR 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 AS 355 (Twin Ecureuil) Series Helicopters

AD/AS 355/57 Amdt 1

Tail Rotor Hub Pitch Change Bearings 11/2002

Applicability: All AS 355 helicopters, versions E, F, F1, F2, and N fitted with tail rotor hub pitch change plate SNR bearing, P/No 6010F234M16 (704A33-651-190).

Requirement: Replace tail rotor pitch change bearings P/No 6010F234M16 (704A33-651-190).

Note: DGAC TAD T2001-073-061(A) refers

Compliance: For AS 355N version:

At 300 flight hours bearing time since new, thereafter at 300 flight bearings hours time since new.

For AS 355 E, F, F1, and F2, versions:

At 1200 flight hours bearing time since new, thereafter at 1200 flight hours bearing time since new.

Transfer of bearings between models:

If bearings are to be transferred from one AS 355 version to another, apply the transfer rules defined in Master Servicing Manual, Chapter 05.99, Page P8.

This Amendment becomes effective on 31 October 2002.

Background: This Airworthiness Directive is prompted by advice from the DGAC that cracks have been found in some tail rotor pitch change plate bearings, which can lead to malfunction of the plate and loss of control of the helicopter.