Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Eurocopter France (formerly Aerospatiale, Society Nationale Industrielle, Sud Aviation) Model SA- 365N, SA-365N1, AS-365N2, and SA-366G1 helicopters. This proposal would require an inspection of the transmission deck for cracks; repair of any cracked transmission decks; and replacement of the transmission deck support beams (support beams) with redesigned support beams. This proposal is prompted by several reports of cracks in the transmission deck and support beams. The actions specified by the proposed AD are intended to detect cracks that reduce the strength of the main gearbox strut attachment and could result in failure of the main gearbox mounting, and subsequent loss of control of the helicopter.