AIR -ENGINE BEARING COOLING -GENERAL DESCRIPTION
EFFECTIVITY BEJ ALL 75-22-00
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D633W101-BEJ Sep 05/2002
AIR -ENGINE BEARING COOLING -NO. 3 BEARING BUFFER AIR COOLER
Component Location
The cooler is on the intermediate case below the fan exit liner at the 2:00 position.
Functional Description
The No. 3 bearing buffer air cooler is a flow-through air-to-air type heat exchanger. The cooler uses 4th stage air to cool the 12th stage HPC bleed air. The cooled air flows through an external tube back to the No. 3 bearing compartment.
EFFECTIVITY BEJ ALL 75-22-00
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AIR -ENGINE BEARING COOLING -NO. 3 BEARING BUFFER AIR COOLER
EFFECTIVITY BEJ ALL POST SB 777-71-0032 75-22-00
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D633W101-BEJ Jan 05/2004
AIR -ENGINE BEARING COOLING -NO. 3 BEARING BUFFER AIR COOLER
EFFECTIVITY BEJ ALL 75-22-00
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D633W101-BEJ Sep 05/2003
PW4000 SERIES ENGINES
777 AIRCRAFT MAINTENANCE MANUAL
THIS PAGE IS INTENTIONALLY LEFT BLANK
75-23-00
Page 1 D633W101-BEJ Sep 05/2002
AIR -ENGINE EXTERNAL ACCESSORY COOLING -GENERAL DESCRIPTION
Purpose
The engine external accessory cooling uses fan air to cool specific engine components and the nacelle zone between the engine and the thrust reverser.
General Description
BEJ ALL POST SB 777-71-0032
Tubes send fan air to these components:
*
Ignition exciters (2)
*
Exciter-to-igniter plug cables (2)
*
Igniter plugs (2)
*
Turbine vane cooling (TVC) air valve actuator
*
Oil pressure transmitter
*
Permanent magnet alternator
*
Pneumatic starter.
BEJ ALL
Tubes send fan air to these components:
*
Ignition exciters (2)
*
Exciter-to-igniter plug cables (2)
*
Igniter plugs (2)
*
Oil pressure transmitter
*
Permanent magnet alternator
*
Pneumatic starter.
The nacelle zone ventilation shutoff valve is on the left thrust reverser. It controls the flow of fan air around the high pressure compressor and the diffuser cases.
The EEC controls the nacelle zone vent ventilation valve as a function of altitude. A dual LVDT supplies position feedback to the EEC. Fault data goes to AIMS.
EFFECTIVITY BEJ ALL 75-23-00
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AIR -ENGINE EXTERNAL ACCESSORY COOLING -GENERAL DESCRIPTION
EFFECTIVITY BEJ ALL POST SB 777-71-0032 75-23-00
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D633W101-BEJ Jan 05/2004
