Cooling air fans are used to?

• A. Induce airflow across the heat exchanger
• B. Cool the engine oil directly
• C. Power electrical systems
• D. Ventilate the cabin exhaust

Answer: (A)

Cooling air fans move air through the heat exchanger so heat from the engine cooling circuit can be carried away by that airflow. The exchanger (often an oil cooler or radiator) does the actual heat transfer, and the fan simply drives sufficient air across it to improve the rate of heat removal. This keeps engine and accessory temperatures within safe limits, especially during ground operations or low-speed flight when ram air is limited.

The other options don’t fit because the fan’s purpose isn’t to cool oil directly by itself, to power electrical systems, or to ventilate cabin exhaust. The oil is cooled indirectly as it passes through the oil cooler with airflow, electrical power comes from the aircraft’s generators, and cabin exhaust ventilation is a separate system.