*
DCV -directional control valve
*
EDIU -engine data interface unit
*
EEC -electronic engine control
*
EICAS -engine indication and crew alerting system
*
ELMS -electrical load management system
*
EPR -engine pressure ratio
*
GSE -ground support equipment
*
IV -isolation valve
*
MAT -maintenance access terminal
*
PDOS -powered door opening system
*
PSEU -proximity sensor electronics unit
*
PSS -proximity sensor system
*
rev -reverse
*
RTO -rejected takeoff
*
RVDT -rotary variable differential transformer
*
SL -sync lock
*
SLV -sync lock valve
EFFECTIVITY BEJ ALL 78-00-00
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PW4000 SERIES ENGINES
777 AIRCRAFT MAINTENANCE MANUAL
ENGINE EXHAUST SYSTEM -INTRODUCTION
EFFECTIVITY BEJ ALL 78-00-00
Page 3
D633W101-BEJ Sep 05/2002
PW4000 SERIES ENGINES
777 AIRCRAFT MAINTENANCE MANUAL
THIS PAGE IS INTENTIONALLY LEFT BLANK
78-00-00
Page 4 D633W101-BEJ Sep 05/2002
ENGINE EXHAUST SYSTEM -GENERAL DESCRIPTION
General
The engine exhaust system controls the direction of the fan exhaust and turbine exhaust gases that make forward thrust and reverse thrust. To make reverse thrust, you use the reverse thrust levers in the flight deck to control the direction of the fan exhaust gases.
Turbine Exhaust System
The turbine exhaust system uses the turbine exhaust sleeve and plug to make an exit duct for the turbine exhaust gases. This system makes forward thrust only.
T/R System
The T/R system uses sleeves, cascade segments, blocker doors, and drag links to control the direction of the fan air exhaust. This system makes forward and reverse thrust.
When the sleeves are forward (retracted), the fan air exhaust makes forward thrust.
When the sleeves are aft (extended), the blocker doors, drag links, and cascade segments turn the fan air exhaust. This makes reverse thrust. The pilot uses reverse thrust to help slow the airplane after landing or during a rejected takeoff (RTO).
EFFECTIVITY
BEJ ALL
Thrust Reverser Actuation System (TRAS)
The TRAS moves the T/R sleeves. It uses hydraulic power for operation and electrical power for control.
Control stand switches energize the sync lock (SL) solenoid valve and the directional control solenoid valve.
The EEC uses a thrust resolver angle (TRA) and other EEC inputs to control the isolation solenoid valve.
The sync lock valve (SLV) supplies hydraulic power to release the sync lock/manual drive unit.
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