FAA AMT (Aviation Maintenance Technician) Airframe Practice Exam

How does the air cycle cooling system produce cold air?

1. By condensing water vapor from the air

2. Extracting heat energy across an expansion turbine

3. Using Freon to cool the air directly

4. Circulating the air over ice packs

The correct answer is: Extracting heat energy across an expansion turbine

The air cycle cooling system produces cold air by extracting heat energy across an expansion turbine. This process works by compressing the incoming air, which raises its temperature. The air is then passed through the expansion turbine, where it expands rapidly, causing a drop in temperature due to the conversion of heat energy into kinetic energy. This results in cold air being produced and circulated throughout the aircraft cabin to regulate temperature. The other options are incorrect because: - Condensing water vapor from the air does not directly produce cold air in the air cycle cooling system. - Using Freon to cool the air directly is not how the air cycle cooling system operates. - Circulating the air over ice packs is not a method employed by the air cycle cooling system to produce cold air.