What does the reduction gearbox do to the engine output?

The reduction gearbox plays a critical role in the overall functioning of an aircraft engine by modifying the rotational speed of the engine output before it drives the propeller. Specifically, the reduction gearbox reduces the RPM of the engine output.

This is essential because aircraft propellers are designed to operate efficiently within a specific RPM range. Aircraft engines typically produce high RPMs, which are not suitable for propeller operation due to potential performance issues and increased noise levels. By reducing the RPM from the engine, the reduction gearbox ensures that the propeller can operate efficiently, optimizing thrust while maintaining a balance between performance and engine longevity.

In flight operations, the reduction of RPM also contributes to better fuel efficiency and improved handling characteristics, which are vital during various phases of flight. Thus, the correct answer accurately reflects the fundamental purpose of the reduction gearbox within the propulsion system of the aircraft.