SUBJECT: INTERVIEW: AIRLINE PILOT
Question No. 1

How does an Air Cycle Machine work?

[ Total Que.:30 ]
Explaination: An air cycle machine mixes both hot and cold air to regulate the temperature of the cabin. Before the air is cooled, it is routed through the primary heat exchanger to be cooled by outside air. The air then flows to the air cycle machine compressor. The compressor increases both air pressure and temperature. The air then goes to secondary heat exchanger and is cooled again. The air is then directed to the ACM turbine resulting in even more heat loss as it helps to power the turbine and in doing so it expands losing more heat. Lastly, the now cold air is routed to a water separator that removes moisture prior to the air entering the cabin. It is at this point that the air mix valve regulates the flow of both hot and cold air to maintain the desired temperature.