The pneumatic system uses pressurized air from the engines, auxiliary power unit (APU), or high-pressure ground connection and sends it to the air-conditioning, engine start, and wing anti-ice systems. A distribution system supplies the pressurized bleed air to the dependent systems. The pneumatic system also monitors the pressure and temperature of the pressurized air.

The pneumatic system consists of an intermediate-pressure bleed air system, high pressure bleed air system, and bleed air leak detection system.

The intermediate-pressure bleed air system uses bleed air from the engines to supply air to the air conditioning system and to the engine starters. Air to the system is supplied either by the engines, auxiliary power unit, or high-pressure ground connection. The AIR COND/BLEED control panel controls the left and right intermediate-pressure bleed air and APU bleed air selection. Two integrated air system (IAS) controllers monitor the intermediate-pressure bleed air system.

The high-pressure bleed air system uses bleed air from the engine high-pressure bleed air port to supply the wing anti-ice system. The flight crew can shut off the high-pressure bleed air with the selection of the wing anti-ice system switches on the anti-ice control panel. The integrated air system (IAS) controllers monitor the high-pressure bleed air system.

The bleed air leak detection system senses leaks from the bleed air ducts that are installed in different locations of the aircraft. The bleed air leak detection system uses the IAS controllers and elements to sense bleed air leaks. A bleed air leak causes a message and indication to display on the engine indicating and crew alerting system (EICAS).