AD FAA-2025-0629

The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC635T2+, and EC135T3 helicopters. This proposed AD was prompted by reports of ruptured and deformed flexible couplings. This proposed AD would require inspecting the axial displacement of the tail rotor driveshaft and, depending on the results, taking corrective actions including inspecting the flexible couplings. This proposed AD would also prohibit installing a tail rotor drive shaft unless certain procedures are followed. These actions are specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference. The FAA is proposing this AD to address the unsafe condition on these products.