What is the flap motor also called?

• A. PDU (Power Drive Unit)
• B. Flap Actuator
• C. Gearbox
• D. Hydraulic Pump

Answer: (A)

In a hydraulically actuated flap system, the device that provides the power to move the flaps is the Power Drive Unit. The flap motor is essentially this integrated unit, because it houses the electric motor that drives the hydraulic pump to create the pressure used by the flap actuators. The actuator itself is the component that converts that hydraulic pressure into the actual flap movement, so it’s not the motor by itself. A gearbox isn’t the flap motor in this setup, and while a hydraulic pump is part of the system, it’s the pump inside the Power Drive Unit, not the entire unit, that defines the flap motor.