What is the function of the main gear reduction/transmission (MGB) in the UH-60, and how is its lubrication maintained?

• A. It provides electrical power to the rotor system.
• B. It stores hydraulic fluid for the main system.
• C. It transfers engine torque to the rotor with the proper reduction ratio; lubricated by a dedicated gear oil circulating via pumps and coolers; monitor oil level and leaks.
• D. It controls rotor blade pitch via electronic signals.

Answer: (C)

The main gear reduction/transmission’s primary job is to take the engine’s high-speed torque and reduce it to the rotor’s lower speed while delivering the required torque to the rotor system. This reduction is essential to keep the rotor turning at the correct RPM for lift and controllability.

Lubrication is provided by a dedicated gear oil system that circulates oil through the gear train with pumps and coolers. This keeps the gears and bearings well-lubricated and helps manage the heat generated by the high loads. The system is monitored by keeping an eye on the oil level and checking for leaks. If the oil level is low or leaks are present, lubrication is compromised, which can lead to overheating or gear damage, so regular checks are important.