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EMERGENCY
PRESSURIZATION SYSTEM
In the event of normal airplane system failure,
the emergency pressurization system may be
activated automatically or manually. This sys-
tem uses bleed-air from the engine low-pres-
s u r e c o m p r e s s o r t o p r o v i d e a i r p l a n e
pressurization and ventilation. This air is not
cooled and the cabin/cockpit may become very
warm. As illustrated in Figure 11-7, both emer-
gency pressurization valves, from the left and
right engine, open allowing the LP bleed-air
into the cabin. The check valves within the
cabin distribution ducts prevent the LP bleed-
air from back flowing into the ECU.
BAGGAGE
COMPARTMENT
HEATING SYSTEM
The baggage compartment heating system pro-
vides heat to warm the unpressurized com-
partment when the temperature falls below 40°
F. The system is designed to prevent luggage
items from freezing and to prevent frost from
forming on the luggage. Other than turning
the system switch ON before flight, operation
of the system is fully automatic and requires
no crew regulation or monitoring.
The system consists of six electrically pow-
ered blanket heaters, an ON/OFF switch, and
control circuitry. The blanket heaters are in-
stalled on all four sides (including the door),
the roof and the floor of the baggage com-
partment. The heaters are self regulating. As
the temperature of the heaters increases, the
power requirement decreases and visa-versa.
The system is powered by the right non-es-
sential bus, and protected by a circuit breaker
located within the tailcone.
The ON/OFF switch is located next to the
baggage compartment light switch (Figure
11-11). The only crew action required is to in-
sure the switch is manually selected to ON
prior to flight into freezing conditions. There
are no cockpit controls or indications for this
system. Service Bulletin, SB 45-21-3 pro-
vides an option of moving the ON/OFF switch
to the cockpit.
11-12
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
international
PYLON
BAGGAGE
COMPARTMENT
LIGHTS
BAGGAGE
HEATER
Figure 11-11. Baggage Heater Switch