The power output flange receives power from which component?

• A. Fuel control unit
• B. Starter motor
• C. Reduction gearbox
• D. Combustion chamber

Answer: (C)

The power output flange gets its mechanical power from the accessory drive system, specifically the reduction gearbox. The turbine drives the gearbox, which lowers the shaft speed and increases torque so it can drive various aircraft systems. The power take-off or output flange on that gearbox provides the usable power to accessories. The other components don’t supply this external drive: the fuel control unit and other accessories draw power from the gearbox, the combustion chamber is where combustion happens, not where usable drive power originates, and while the starter motor may interact with the gearbox during starting, the actual source of the flange’s power is the reduction gearbox driven by the engine core.