Which component provides a mounting and drive for essential components such as hydraulic pumps, generators, rotor brake discs, etc?

• A. Driveshaft sections
• B. Main gearbox/Main Transmission
• C. Tail gearbox
• D. Accessory Gearboxes/Drives

Answer: (D)

The essential concept here is how a helicopter distributes power to its auxiliary systems. The accessory gearbox (or accessory drives) is the unit that provides both a mounting point and a driven path for important subsystems like hydraulic pumps, electrical generators, and rotor brake discs. It is typically driven by the engine or by the main gearbox and serves as a centralized hub for these components, ensuring they operate at the correct speed and stay physically secured in one location.

The main gearbox’s primary role is to reduce engine RPM to the rotor RPM and to transfer power to the main rotor system; it isn’t primarily a mounting hub for all accessories. The tail gearbox handles the tail rotor drive, and driveshafts simply transmit power between components. Because the question emphasizes a mounting and drive for those essential components, the accessory gearboxes/drives are the best fit.