What is the purpose of the lubrication system in a gas turbine engine?

• A. To lubricate components only during start.
• B. To lubricate bearings and gears, remove heat, prevent corrosion, and support seals and oil flow paths.
• C. To cool the combustor.
• D. To provide hydraulic power only.

Answer: (B)

The lubrication system in a gas turbine has several essential roles that keep the rotating parts reliable and efficient. It provides a protective film between bearings and gears, reducing wear from high-speed movement and dynamic loads. Oil is pumped through internal galleries to bearings, gear meshes, and accessory gearboxes, carrying away friction heat to an external cooler so temperatures stay under control. It also helps prevent corrosion by maintaining a protective oil film and by removing moisture from exposed surfaces. In addition, the oil helps seals by supplying a controlled, pressurized barrier and guiding oil through the required seal paths, ensuring proper oil flow and preventing leaks or cavitation in the oil system. This combination of lubrication, cooling, corrosion protection, and seal support is what the lubrication system delivers, making it the correct description. The other options miss key functions: lubrication isn’t needed only at start, it doesn’t cool the combustor directly, and it isn’t just a source of hydraulic power.