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 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/74 Main Gear Box - Planet Gear Carrier 1/2005

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Applicability: EUROCOPTER helicopters: SA 365 N and N1, AS 365 N2 and N3, SA 366 G1, SA 365 C, C1, C2 and C3, SA 360.

Requirement: 1. Check the main gearbox (MGB) magnetic plug, both with and without electrical indicating, in accordance with Paragraph 2B of the applicable reference document.

2. For rotorcraft equipped with an MGB magnetic plug with electrical indicating, check the plug in accordance with Paragraph 2B of the applicable reference document.

REFERENCE DOCUMENTS:

EUROCOPTER AS 365 N Alert Telex No. 05.00.47 EUROCOPTER SA 366 Alert Telex No. 05.32 EUROCOPTER SA 360 and SA365 C Alert Telex No. 05.24

(Any subsequent DGAC approved revision to these Alert Telexes is acceptable).

Note: DGAC UF 2004-181 (EASA reference No 2004-11051 dated 12 November 2004.) refers.

Compliance: For requirement 1:

MGBs with less than 50 flying hours TSO/TSN on the effective date of this directive, at the next ALF-check prior to the MGB exceeding 50 flying hours TSO/TSN, and thereafter repeat at intervals not exceeding flying 10 hours.

MGBs with 50 flying hours TSO /TSN or more on the effective date of this directive, at the next ALF-check within 10 flying hours, and thereafter, repeat at intervals not exceeding 10 flying hours.

For requirement 2:

Before the next flight after the illumination of the chip warning light.

Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters

AD/DAUPHIN/74 (continued)

This Airworthiness Directive becomes effective on 19 November 2004.

Background: This AD is issued following two cases of cracks that were discovered in the web of the planet gear carriers of two main gearboxes. The cracks were discovered upon removal of the MGB’s after metal chips were detected at the magnetic plug.

Eurocopter advise that it appears that cracking can only be detected by chips on the magnetic plug, and that during the initial cracking phase the formation of metal particles can be below the currently applicable removal requirement provided in MTC Work Card 20.08.01.601. Rupture of the web of the planet gear carrier can lead to seizure of the MGB.

James Coyne

Delegate of the Civil Aviation Safety Authority 18 November 2004

The above AD is notified in the Commonwealth of Australia Gazette on 19 November 2004.