Which component carries transmission torque to the tail rotor gearbox?

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

Answer: (D)

In helicopter drive systems, power flows from the engine through the main gearbox and then along a driveshaft system toward the tail. The intermediate gearbox sits along the tail drive path and serves as the transfer point that receives torque from the drive shafts coming from the main gearbox and then feeds it into the tail rotor gearbox. It effectively carries and routes the transmission torque to the tail rotor gearbox, handling the direction change and any required gear reduction to suit the tail rotor. The main gearbox is the power source, and the tail rotor gearbox is the destination; the intermediate gearbox is the stage that actually conveys the torque along the path to the tail rotor.