Pneumatics

The pneumatic system provides high pressure air for the normal and emergency operation of the canopies, and the emergency operation of the landing gear and slats flaps. Air for the pneumatic system is drawn from the engine bleed air supply, via the electronic equipment cooling system, and is compressed by a hydraulic motor driven air compressor. A pneumatic pressure sensor in the system moisture separator opens a hydraulic shutoff valve, to activate the air compressor, when the system pressure falls below 2750 +50 -0 psi. When the pneumatic system pressure builds to 3100 +100 -50 psi, the pneumatic pressure sensor closes the hydraulic shutoff valve which de-activates the air compressor. Normal system pressure range is from 2650 to 3300 psi due to pressure transmitter and pressure gage tolerances.

The pressurized air from the air compressor is then fed into the different tanks which can supply it to several systems:

• Canopies
• Landing gear (in emergency mode)
• Slats and flaps (in emergency mode)

A Pneumatic Pressure Indicator is found on the front cockpit pedestal panel. It indicates manifold pressure of the system.