What does the lubrication system do?

• A. Provides lubrication and cooling to bearings and gears.
• B. Stores hydraulic fluid for flight controls.
• C. Regulates fuel flow to the combustion chamber.
• D. Delivers oil to cockpit instruments.

Answer: (A)

The lubrication system keeps moving parts like bearings and gears from overheating and wearing by delivering oil under pressure to those surfaces. The oil forms a protective film that reduces metal-to-metal contact, carries heat away to an oil cooler, and helps clean passages by picking up particulates. A return/scavenge path keeps the oil circulating and the sump level steady, so the engine stays lubricated even under high-load, high-speed operation.

Storing hydraulic fluid, regulating fuel flow, or delivering oil to cockpit instruments aren’t functions of the lubrication system. Hydraulic fluid is for the hydraulic flight-control system, fuel flow is managed by the fuel control system, and cockpit instruments aren’t fed lubrication oil.