Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Helicopters Model EC 155B and EC155B1 helicopters. This proposed AD was prompted by a report that non-destructive tests of the main gearbox (MGB) housing may have been evaluated incorrectly during production. This proposed AD would require replacing affected MGBs with serviceable MGBs, as specified in a European Union Aviation Safety Agency (EASA) AD, which will be incorporated by reference. The FAA is proposing this AD to address the unsafe condition on these products.