The main gear drives the main rotor, tail rotor, and accessories. What does the main transmission reduce?

• A. The torque from the engines
• B. The input RPM of the two engines
• C. The weight of the helicopter
• D. The hydraulic pressure

Answer: (B)

The main transmission plays a crucial role in helicopter mechanics by adjusting the input revolutions per minute (RPM) from the engines to a speed that is manageable and appropriate for the main rotor and other components. Helicopter engines typically operate at high RPMs, which must be reduced so that the rotor system can function effectively and safely without exceeding design limits. By translating and reducing the engine speed, the main transmission provides the necessary lower RPMs required for optimal rotor performance and operational stability. This process is essential for ensuring that the helicopter can achieve its lift and maneuverability effectively while maintaining safety and control during flight.