Pressurization System Description
Cabin pressurization is controlled during all phases of airplane operation by the cabin
pressure control system. The cabin pressure control system includes two identical
automatic controllers available by selecting AUTO or ALTN and a manual (MAN) pilot–
controlled mode.
The system uses bleed air supplied to and distributed by the air conditioning system.
Pressurization and ventilation is controlled by modulating the outflow valve and the
overboard exhaust valve.
Pressure Relief Valves
Two pressure relief valves provide safety pressure relief by limiting the differential pressure
to a maximum of 9.1 psi. A negative relief valve prevents external atmospheric pressure
from exceeding internal cabin pressure.
