Which component is located at the base of the tail pylon and carries transmission torque to the tail rotor gearbox?

• A. Main gearbox/Main Transmission
• B. Tail gearbox
• C. Intermediate gear box
• D. Driveshaft sections

Answer: (C)

The drive path from the main gearbox to the tail rotor goes through an intermediate gear box located at the base of the tail pylon. This intermediate gearbox accepts torque from the main gear train via the tail drive shafts, uses bevel gears to redirect the drive down the tail, and then forwards the torque into the tail rotor gearbox. It serves as the interface that turns and routes power toward the tail rotor system, while the tail rotor gearbox at the tail rotor itself handles the final reduction and drive to the rotor. Driveshaft sections carry the torque along, but they don’t perform the gear reduction or redirection that the intermediate gearbox provides.