The air source of the air-conditioning system​ can be divided into two categories, one is the hot air flow drawn from the aircraft system, which enters the cabin under the action of the air-conditioning components; the other is the ram air from the outside, which is mainly used to cool the air from the aircraft system. The gas introduced to the air conditioning unit is discharged directly after use.

The bleed air from the low-pressure compressor of the engine is decompressed by the pressure regulator and cooled by the pre-cooling air valve, and then enters the air supply main pipe at 35psi (2.4 atmospheres) and 220 degrees Celsius, and flows through the engine hanger, the leading edge of the large wing, and the front wall of the wheel well. After the board enters two air conditioning components located in the belly of the aircraft.