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/77 Main Gearbox (MGB) Planet Gear Carrier 2/2005
TX
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, EC 155 B, B1.
Requirement: | 1. | Carry out a boroscope inspection in accordance with Paragraph 2B of the applicable reference document. |
| 2 | Carry out a visual inspection in accordance with Paragraph 2B.3 of the applicable reference document |
REFERENCE PUBLICATIONS:
EUROCOPTER AS 365 N Alert Telex No. 05.00.48 EUROCOPTER SA 366 Alert Telex No. 05.33 EUROCOPTER SA 360 and SA365 C Alert Telex No. 05.26 EUROCOPTER EC 155 Alert Telex No. 05A007
(Any subsequent approved revision to these Alert Telexes is acceptable).
Note: DGAC UF 2004-194 (EASA reference No 2004-12387 dated 17 December 2004) refers.
Compliance: For requirement 1:
MGBs with less than 250 hours Time In Service (TIS), before exceeding 265 hours TIS, and thereafter at intervals not to exceed 50 flying hours.
MGBs with 250 flying hours TIS or more, within 15 hours TIS after the effective date of this Directive, and thereafter at intervals not to exceed 50 flying hours.
For requirement 2:
Before installation in the rotorcraft
This Airworthiness Directive becomes effective on 30 December 2004.
Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters
AD/DAUPHIN/77 (continued)
Background: This AD is issued following cases of cracks that were discovered in the web of the planet gear carriers of the main gearbox, but which did not provide any indication on the magnetic plug, as detailed in AD/DAUPHIN/74.
The cracks were discovered upon inspection of the MGB’s using a boroscope, even though chips were not showing on the magnetic plug. 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 23 December 2004
The above AD is notified in the Commonwealth of Australia Gazette on 24 December 2004.