Summary
This document proposes the supersedure of an existing airworthiness directive (AD) for Eurocopter France Model AS-350B, BA, B1, B2, and D; and AS-355E, F, F1, F2, and N helicopters. That AD currently requires inspecting the main gearbox suspension bi-directional cross beam (cross beam) for cracks, replacing the cross beam if a crack is found, and adding time intervals for repetitive dye- penetrant inspections on cross beams with 5,000 or more hours time-in- service (TIS). This action would require the same inspections as the existing AD but would delete repetitive dye-penetrant inspections on cross beams with 5,000 or more hours TIS. This proposal is prompted by the discovery that repetitive dye-penetrant inspections were erroneously required in the existing AD. The actions specified by the proposed AD are intended to prevent failure of the cross beam that could lead to rotation of the main gearbox, severe vibrations, and a subsequent forced landing.