FlightSafety LEARJET 45 - INTRODUCTION; GENERAL

INTRODUCTION
The Learjet 45 pressurization system maintains a cabin altitude much lower than actual
airplane altitude. This is accomplished by controlling the outflow of air that has been
provided to the occupied areas of the airplane through pneumatic, air conditioning and
ventilation distribution systems.
The pressurized area of the airplane extends
from the forward pressure bulkhead, separat-
ing the cockpit from the nose avionics bay, to
the aft pressure bulkhead. A supply of condi-
tioned engine bleed-air is supplied through
the environmental control unit (ECU) and the
outflow is controlled by two outflow valves lo-
cated on the forward pressure bulkhead.
Regulating the outflow of air through the out-
flow valves is provided by the dual channel
cabin pressure control system (CPCS), lo-
cated in the cockpit. The CPCS regulates the
cabin pressurization system automatically,
based upon a pressurization schedule. The
crew can also regulate cabin pressure by man-
ually selecting the rate of change. During
emergency pressurization, the bleed-air en-
tering the cabin and cockpit, bypassing the
ECU and temperature control system, also
provides a source of pressurization which is
regulated by the CPCS in the same manner.
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CHAPTER 12
PRESSURIZATION
12-1
FOR TRAINING PURPOSES ONLY
LEARJET 45 PILOT TRAINING MANUAL
FlightSafety
international
GENERAL