ENGINE 1 ENGINE 2
SYSTEM A SYSTEM B
HYDRAULIC HYDRAULIC
PRESSURE PRESSURE
CONTROL ACTUATOR
VALVE
(STOW) STOWED AND
LOCKED
1
ELECTRO-VALVE
ISOLATION
MECHANICAL LOCK
(CLOSED)
(LOCKED)
FAN FLOW
CASCADE
TRANSLATING VANES SLEEVE
1
As Installed
MAXIMUM REVERSE THRUST
FORWARD
THRUST
LEVER
REVERSE THRUST (DEPLOYED)
SYSTEM STANDBY SYSTEM
A SYSTEM B
ENGINE 1
ENGINE 2 SYSTEM A
SYSTEM B HYDRAULIC
HYDRAULIC ACTUATOR
PRESSURE
PRESSURE CONTROL VALVE (DEPLOY) DEPLOY
1
ELECTRO-
ISOLATION
MECHANICAL
VALVE
LOCK (UNLOCKED)
(OPEN)
BLOCKER DOOR
FAN FLOW
TRANSLATING CASCADE SLEEVE VANES
Copyright . The Boeing Company. See title page for details.
7.20.12 June 6, 2003
737 Operations Manual
Introduction
The auxiliary power unit (APU) is a self–contained gas turbine engine installed
within a fireproof compartment located in the tail of the airplane. The APU supplies bleed air for engine starting or air conditioning. An AC electrical generator on the APU provides an auxiliary AC power source.
APU Location
APU Operation
The APU operates up to the airplane maximum certified altitude.
The APU supplies bleed air for one air conditioning pack (two air conditioning packs for –280 APU) either on the ground or in flight. Both generator busses can be powered on the ground. In flight only one generator bus can be powered.
APU Fuel Supply
Fuel to start and operate the APU comes from the left side of the fuel manifold when the AC fuel pumps are operating. If the AC fuel pumps are not operating, fuel is suction fed from the No. 1 tank. During APU operation, fuel is automatically heated to prevent icing.
Engines, APU -APU System Description
737 Operations Manual
With the APU operating and AC electrical power on the airplane busses, operate
at least one fuel boost pump to supply fuel under pressure to the APU. On some airplanes a DC operated APU fuel boost pump provides positive fuel pressure to the APU fuel control unit. During APU start and operation, the pump operates automatically, and shuts off automatically once the APU is at governed speed and is ready to accept a load.
APU Engine and Cooling Air
APU engine and cooling air is routed to the APU through an automatically operated air inlet door located on the right side of the fuselage. APU exhaust gases are discharged overboard through an exhaust muffler.
The APU oil cooler and electrical generator are provided positive cooling airflow by a gear-driven fan.
Electrical Requirements for APU Operation
APU operation requires the following:
.
APU fire switch on the overheat/fire panel must be IN
.
APU fire control handle on the APU ground control panel must be IN
.
Battery switch must be ON. Electrical power to start the APU comes from the airplane battery. Moving the battery switch to OFF on the ground shuts down the APU.
APU Start
The automatic start sequence begins by moving the APU switch momentarily to START. This initiates opening of the air inlet door. When the APU inlet door reaches the full open position the start sequence begins. After the APU reaches the proper speed, ignition and fuel are provided. When the APU is ready to accept a bleed air or electrical load the APU GEN OFF BUS light illuminates.
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本文链接地址:737-300机组操作手册Flight Crew Operations Manual FCOM 2(64)