The Avionics Fan caution displays when the fan speed falls below what percent?

The Avionics Fan caution displays when the fan speed falls below what percent?

• A. 60%
• B. 50%
• C. 70%
• D. 40%

Answer: (A)

Cooling performance for avionics depends on adequate fan speed, since a low RPM means air isn’t flowing enough to remove heat. The caution is designed to light up when the fan speed drops below 60% of its normal running speed, giving a safety margin to catch reduced cooling before temperatures rise too high. This threshold balances catching genuine problems without nagging on minor fluctuations, so you get a timely alert if the fan or its power path starts to fail, while avoiding false alarms during normal operation. If you see the caution, inspect the fan, its power supply, wiring, and the air path for obstructions or failures. Lowering the threshold to something like 50% would delay warning and risk overheating, while a threshold as high as 70% would trigger alarms too often in normal conditions.

Cooling performance for avionics depends on adequate fan speed, since a low RPM means air isn’t flowing enough to remove heat. The caution is designed to light up when the fan speed drops below 60% of its normal running speed, giving a safety margin to catch reduced cooling before temperatures rise too high. This threshold balances catching genuine problems without nagging on minor fluctuations, so you get a timely alert if the fan or its power path starts to fail, while avoiding false alarms during normal operation. If you see the caution, inspect the fan, its power supply, wiring, and the air path for obstructions or failures. Lowering the threshold to something like 50% would delay warning and risk overheating, while a threshold as high as 70% would trigger alarms too often in normal conditions.