AD FAA-2015-4497

The FAA is adopting a new airworthiness directive (AD) for Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model BO-105A, BO-105C, BO-105S, MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB- BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117 C-1 helicopters. This AD was prompted by a report of a loss of electrical ground between the starter-generator and the generator voltage regulator (regulator). This AD requires inspecting the starter-generator electrical ground connection, retrofitting the starter-generator wire harness, and depending on model, revising the existing Rotorcraft Flight Manual (RFM) for your helicopter. The FAA is issuing this AD to address the unsafe condition on these products.