How does the reduction gearbox affect the main driveshaft's RPM?

How does the reduction gearbox affect the main driveshaft's RPM?

• A. Increases RPM significantly
• B. Decreases RPM and changes direction
• C. Maintains RPM constant
• D. Increases RPM slightly

Answer: (B)

The reduction gearbox is designed specifically to alter the speed and torque characteristics of the drive system in a helicopter. In this context, it decreases the RPM of the main driveshaft while simultaneously changing its direction if necessary, depending on the design of the gearbox. The main purpose of a reduction gearbox is to allow the engine to operate at a higher RPM where it is more efficient and to reduce that speed to a level that is suitable for the rotor system. This reduction is critical in achieving the necessary torque for starting rotor movement without compromising engine performance. The gearbox translates the high-speed input from the engine to lower-speed output suitable for rotor rotation, optimizing performance and ensuring proper operation of the helicopter's flight systems. This functionality is crucial in aviation because it directly affects the efficiency and effectiveness of the rotor systems, and it is essential for maintaining stable flight. By reducing RPM, the gearbox ensures that the rotor spins at a controlled rate that is both safe and effective for flight operations.

The reduction gearbox is designed specifically to alter the speed and torque characteristics of the drive system in a helicopter. In this context, it decreases the RPM of the main driveshaft while simultaneously changing its direction if necessary, depending on the design of the gearbox.

The main purpose of a reduction gearbox is to allow the engine to operate at a higher RPM where it is more efficient and to reduce that speed to a level that is suitable for the rotor system. This reduction is critical in achieving the necessary torque for starting rotor movement without compromising engine performance. The gearbox translates the high-speed input from the engine to lower-speed output suitable for rotor rotation, optimizing performance and ensuring proper operation of the helicopter's flight systems.

This functionality is crucial in aviation because it directly affects the efficiency and effectiveness of the rotor systems, and it is essential for maintaining stable flight. By reducing RPM, the gearbox ensures that the rotor spins at a controlled rate that is both safe and effective for flight operations.