Applicability: AS 332 C, AS 332 C1, AS 332 L and AS 332 L1 helicopters, all serial numbers, if averaging more than 4 torque variation cycles per flight hour.

Requirement:

1. Ensure that there is no crack by visually checking for absence of oil leaks on the MGB main casing RH face, in accordance with the instructions given in paragraph 2.B of Eurocopter AS 332 Alert Service Bulletin (ASB) No. 05.00.66.
2. Analysis of the results:
3. 1. If there is no oil leak, resume flights in accordance with the instructions specified in paragraph 2.B.2.a of AS 332 ASB No. 05.00.66 or later DGAC approved revision.
   2. If an oil leak is found, before further flight, replace the MGB in accordance with the instructions specified in paragraph 2.B.2.b of AS 332 ASB No. 05.00.66 or later DGAC approved revision. Replacement of the MGB does not constitute terminating action for the repetitive inspection requirements of this AD.

Note: EASA Emergency AD 2006-0361-E dated 30 November 2006 refers.

Compliance: Within the next 20 flight hours (FH) or 400 torque cycles, whichever occurs first after the effective date of this directive, and thereafter at intervals not exceeding 110 FH or 2,200 torque cycles, whichever occurs first.

This Airworthiness Directive becomes effective on 4 December 2006.

Background: This AD is issued following a crack which was discovered in one of the inner ribs of the main casing during major overhaul of a main gearbox (MGB) at EUROCOPTER. The MGB concerned was installed on a helicopter specifically used for “heli-logging” missions involving frequent torque variations. In the event of intensive operation of the helicopter, the crack can grow and lead to an MGB oil leak and thus give rise to an emergency situation affecting flight safety.

FMI: www.casa.gov.au