AD FAA-2021-0135

The FAA proposes to supersede Airworthiness Directive (AD) 2019-07-07 for various Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model MBB-BK117 and Model BO-105 helicopters. AD 2019-07- 07 requires removing certain part numbered swashplate bellows (bellows) from service, cleaning and inspecting certain parts, and depending on the inspection results removing certain parts from service, applying torque, and repetitively inspecting the swashplate assembly (swashplate). AD 2019-07-07 also prohibits the installation of certain part-numbered bellows. This proposed AD would retain certain requirements of AD 2019-07-07, expand the installation prohibition, add additional inspections, and update the applicable service information. The actions of this proposed AD are intended to address an unsafe condition on these products.