The Bypass Door Actuator (BDA) is an electrically controlled and powered linear actuator. It is used to position the aircraft bypass door. 

The BDA consists of single electric Brushless Motor powered at 28 VDC and electronic control unit to provide the BDA actuation by discrete signals. 

The BDA can be positioned in open/close configuration and the Power-Off Brake allows the BDA to maintain irreversibly its position without power consumption.

Two Limit Switches define the BDA electrical stroke.