Airworthiness Directives; Airbus Helicopters Deutschland GmbH Helicopters

The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 D-3 helicopters. This proposed AD was prompted by reports of momentary direct current (DC) power interruption in flight of both essential busses. This proposed AD would require revising the existing rotorcraft flight manual (RFM) for your helicopter, as 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.