Patent ID: 7270125

Claim:
A method of operating a gas system, comprising the steps of: in a gas system which includes a first system and a second system connectable to test aircrew systems, selecting from among one of a test mode simulating normal human breathing and a test mode simulating pressure human breathing while under gravitational forces greater than occurring during said normal breathing; filtering ambient air with a chemical filter; compressing the air; monitoring a flow of the air; and during said test mode, selectively monitoring pressure of the air in said flow through said first system and said second system; wherein said first system comprises a mask, and said second system comprises a G-suit; and wherein, when said test mode for said pressure breathing is selected, the step of compressing said air further comprises the steps of: turning on a first compressor; turning off said first compressor and turning on a second compressor when a pressure of said G-suit reaches a first predetermined point; and turning off said second compressor when said pressure of said G-suit reaches a second predetermined point.