AD FAA-2011-1075

This amendment adopts a new airworthiness directive (AD) for ECD Model MBB-BK 117 C-2 helicopters. This action requires revising the Rotorcraft Flight Manual (RFM) by inserting certain temporary pages into the Emergency and Performance Data sections of the RFM to alert the operators to monitor the power display when a generator is deactivated and provides appropriate actions. This amendment is prompted by reports of too high a current flow when one generator is deactivated. The actions specified in this AD are intended to prevent failure of the remaining generator when one generator is deactivated, loss of electrical power, loss of systems necessary for flight safety, and subsequent loss of control of the helicopter.