Summary
We propose to adopt a new airworthiness directive (AD) for Airbus Helicopters Deutschland GmbH (Airbus Helicopters) MBB-BK 117 D-2 helicopters. This proposed AD would require repetitively inspecting the bushings of the inner and outer forward trusses of both engines. This proposed AD is prompted by reports of delaminated and worn engine mount bushings. The proposed actions are intended to detect delaminated engine mount bushings, which can lead to excessive vibration, cracking, failure of the engine mount front support pins, and loss of helicopter control.