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 39.1 (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 355/61 Starter Generators 2/2002 TX

Applicability:  Model AS 355N helicopters fitted with starter generators Part Number (P/N) 524-060 or 524-061.

Requirement: 1. For starter generators installed after the effective date of this Directive:

1. Perform vibration level checks in accordance with the procedure described in Paragraph 2 of Eurocopter Alert Telex No 01.00.45 R3 dated 22 November 2001.

b.             Check the tightening torque of the starter generator attachment clamp in accordance with maintenance manual (MET) work card 80.06.00.401.

2.        For starter generators already installed on helicopters as at the effective date of this Directive:

1. If the starter generator has completed more than 15 hours TIS since installation - Check the tightening torque load of the starter generator attachment clamp in accordance with MET work card 80.06.00.401.

b.             If the starter generator has completed more than 110 hours time in service (TIS) since installation - Check the vibration level once, in accordance with the procedure described in Paragraph 2 of Eurocopter Alert Telex No

01.00.45 R3.

Note: DGAC AD 1999-469-058(A) R2 refers.

Compliance:  For Requirement 1.a. - Before further flight, after each installation of a starter generator and then at the following intervals:

After 10 to 15 hours TIS

After 25 to 35 hours TIS

After 45 to 55 hours TIS

After 70 to 80 hours TIS

After 100 to 110 hours TIS

and thereafter every 110 hours TIS.

Eurocopter AS 355 (Twin Ecureuil) Series Helicopters

AD/AS 355/61 (continued)

For Requirement 1.b. - Concurrent with the Requirement 1 vibration level check performed at 10 to 15 hours TIS.

For Requirement 2.a. - Before the next flight, after the effective date of this Directive.

For Requirement 2.b. - Within 15 hours TIS from the effective date of this Directive, unless the check had been performed previously in accordance with AD/AS 355/56, and thereafter at intervals not to exceed 110 hours TIS.

This Airworthiness Directive becomes effective on 14 January 2002.

Background: The DGAC advised that in some cases starter generator wear/vibration has resulted in cracks which, if not corrected, may lead to failure of the engine exhaust pipe attachment lugs. This in turn may result in loss of part of the exhaust pipe system.

This Directive requires repetitive inspection and vibration checks to detect early failure of the starter generators.

This Directive supersedes AD/AS 355/56, which has been cancelled.

Neville Probert

Delegate of the Civil Aviation Safety Authority 11 January 2002

The above AD is notified in the Commonwealth of Australia Gazette on 14 January 2002.