PW4000 SERIES ENGINES
777 AIRCRAFT MAINTENANCE MANUAL
ENGINE STARTING -GENERAL DESCRIPTION
EFFECTIVITY BEJ ALL 80-00-00
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ENGINE STARTING -COMPONENT LOCATIONS -ENGINE
General
You open the fan cowls and thrust reversers to get access to these engine starting system components:
*
Starter air supply duct
*
Starter air valve
*
Starter
*
Starter air valve solenoid.
Starter Air Valve Solenoid
The starter air valve solenoid is on the intermediate case at the
1:00 position near the forward lower engine mount.
EFFECTIVITY BEJ ALL 80-00-00
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D633W101-BEJ Sep 05/2002
ENGINE STARTING -COMPONENT LOCATIONS -ENGINE
EFFECTIVITY BEJ ALL 80-00-00
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D633W101-BEJ Sep 05/2002
ENGINE STARTING -COMPONENT LOCATIONS -FLIGHT DECK
Engine Start Controls
The engine start/ignition selectors and the autostart switch are on the cargo fire/engine control panel on the P5 overhead panel.
EFFECTIVITY BEJ ALL 80-00-00
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D633W101-BEJ Sep 05/2002
ENGINE STARTING -COMPONENT LOCATIONS -FLIGHT DECK
EFFECTIVITY BEJ ALL 80-00-00
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D633W101-BEJ Sep 05/2002
ENGINE STARTING -STARTER AIR VALVE
Purpose
The starter air valve (SAV) opens to let air go to the starter.
Physical Description
The SAV is a poppet-type valve. It is pneumatically controlled and operated.
Functional Description
A spring holds the SAV closed. Servo air opens the SAV. How far the valve opens is related to the level of the servo air pressure that comes from the SAV solenoid.
Manual Override
You can manually open the SAV if it does not operate automatically. Use a 3/8 inch square drive to manually open the valve. You get access to the manual override through a guide tube behind the center thrust reverser latch access door.
EFFECTIVITY BEJ ALL 80-00-00
Page 10
D633W101-BEJ Sep 05/2002
PW4000 SERIES ENGINES
777 AIRCRAFT MAINTENANCE MANUAL
ENGINE STARTING -STARTER AIR VALVE
EFFECTIVITY BEJ ALL 80-00-00
Page 11
D633W101-BEJ Sep 05/2002
ENGINE STARTING -STARTER AIR VALVE SOLENOID AND FILTER
General
The starter air valve solenoid controls the servo air that opens the starter air valve (SAV). You get access to the starter air valve solenoid with the right thrust reverser half open.
Functional Description
The EEC controls a switch in the engine relay unit. When this switch closes, 28v dc power energizes the SAV solenoid that opens an internal valve. This lets the servo air supply go to the SAV to open it. A filter cleans the servo air.
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本文链接地址：777 AMM 飞机维护手册 发动机起动 Engine Starting PW 777 AIRCRAFT MAINTENANCE MANUAL(3)
