Drive system: What are the functions of the prop-rotor drive system?

• A. Primarily transmits torque from the engines to the prop-rotors; secondary provides synchronization enabling single engine operation
• B. Transmits electrical power to cockpit
• C. Lubricates gears
• D. Controls blade pitch

Answer: (A)

The prop-rotor drive system is mainly responsible for getting engine power to the rotors and keeping them working together as a unit. It transmits the engine’s torque through shafts and gears to spin the prop-rotors at the correct speed. A key part of this system is its synchronization capability, which ties the two drive paths together so the rotors stay in step. This synchronization lets one engine drive both rotors if needed, maintaining proper rotor speeds and preventing dangerous differences in load or phase. Roles like providing electrical power, lubricating gears, or adjusting blade pitch belong to other subsystems, not the drive system. So the combination of transmitting torque and enabling synchronized operation for single-engine use best describes its function.