Action
Final rule.
Summary
The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Model EC155B1 helicopters. This AD was prompted by reports of failure of the main gearbox (MGB) oil cooling fan hub (fan hub). This AD requires, for helicopters with an affected part (fan hub) installed, using an endoscope, repetitively inspecting the fan hub, including the area around the fan hub attachment screws, for a crack. Depending on the inspection results, this AD requires performing additional inspections and replacing an affected fan hub. This AD also allows an affected fan hub to be installed on a helicopter if certain actions are accomplished, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.