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When armed, the passenger oxygen distribu-
tion system is automatically controlled by the
cabin pressure controller (CPCS). Upon sens-
ing a cabin altitude at 14,500' or above, the
controller opens the passenger oxygen control
valve and initiates deployment of the passen-
ger oxygen masks. The automatic deployment
also illuminates the ON caption within the
DEPLOY switch on the control panel and ini-
tiates a white “PAX OXY DEPLOY” message
on the CAS.
Manual deployment of the masks occurs when
the DEPLOY switch/indicator is depressed
(Figure 17-12). The DEPLOY switch illumi-
nates ON when it has been manually depressed
or automatically activated. Activation of the
DEPLOY switch opens the passenger oxygen
control valve and initiates deployment of the
passenger oxygen masks. Once activated, a
white “PAX OXY DEPLOY” message will be
displayed on the CAS. The DEPLOY switch
can be used to deploy the passenger masks
even if the PAX OXY/AUTO switch is “OFF.”
The OFF annunciation in the PAX OXY/AUTO
switch would extinguish if the passenger oxy-
gen was manually deployed.
The passenger mask storage compartment
doors are normally held closed with latches.
When oxygen is admitted to the passenger
distribution system, the oxygen pressure
causes the door actuators (plungers) to push
outward, opening each compartment door.
When the doors open, the passenger masks
fall free and are available for passenger don-
ning. Each passenger must pull the oxygen
supply lanyard to initiate oxygen flow. The
reservoir bag may seem to inflate slowly, but
this is normal.
The passenger oxygen distribution system is
28 VDC powered from the airplane emergency
battery bus. It is protected by the PAX OXY
circuit breaker located within the environ-
mental group on the pilot circuit breaker panel.
System operation is unaffected with either a
single or a dual generator failure. Passenger
17-11
FOR TRAINING PURPOSES ONLY
L E A R J E T 4 5
P I L O T T R A I N I N G M A N U A L
FlightSafety
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Figure 17-12. PAX OXYGEN and
PRESSURIZATION Control Panel
Figure 17-11. Passenger Oxygen Mask