Engines Flashcards
thrust and engine
Rolls Royce BR715 high bypass turbo fan 21000 lbs of thrust
reverser status displayed
u/l, 90, red, 30sec, idle, emergency amber
reverse idle detent EEC’s will unlock and deploy reversers provided EEC not detecting failures
when out of stowed U/L displayed inside the EPR arcs 90% deployed REV in green
Red REV if there is an unommanded deployment in flight
Only deploy when respective engine is running, However if the engine is shutdown the reverser on the inop engine is permitted for 30 sec after nose wheel compression
bult in safety feature prevent uncommanded in flight EEC automatically reduce thrust to idle
Emergency reverse thrust is available by pulling the levers through mechanical gate can damage engine
Amber REV will be displayed until cleared by ENG EXCEEDANCE reset.
engine synchronization
matches EPR or fan speed EEC automatically controls system takeoff left EPR to right EPR During climb , cruise and descent synchronizes fan speeds
warmup and cool down times
3 min or low vibration levels , non within 3 hours, 3 min cool down prior to shutdown ENGINE COOL ALERT
current EPR throttle position and Computed EPR are depicted on the EAD
EPR primary thrust setting, T indicates throttle position white line is actual, Magenta V computed EPR when T fits within V at computed thrust setting
Indications of automatically aborted engine how resetr
EAD message ENG L/R start Abort cancelled by selecting fuel switch off
indications of excessive engine vibration
digits in white will turn amber and be boxed in amber if vibration exceeds limit
conditions where engine start should not be attempted
32,42,25 for 15
oil temp not above limit
starter pressure below 32 above 43
if below 25 for more than 15 sec after ENG START pulled START AIR PRESS LO alert will be displayed . Light threshold is below 32psi limit
Normal and abnormal apu parameters displayed
% RPM white-red white becomes red and boxed when limits exceeded
% EGT white red white to red and boxed and return to white when limits return to normal
Precautions concerning APU restart
Shutdown fault must be cleared
7% off then on sd gone
start or shuts down automatically shutdown fault must be cleared —-below 7%rpm move master to off then use normal procedures
If APU fails to start do not attempt start until after APU parameters on Secondary synoptic are no longer displayed (provide time for unburned fuel in the APU to drain out. May emit smoke)
ECU automatically shut down APU when fault detected
amber 2, inflight only (overspeed, fire) 10min
AMBER APU fault 2 conditions which could result in APU damage inflight
On ground – APU automatically shuts down, fuel shutoff closes,amber APU AUTO SHUTDOWN displayed
INFIGHT ECU automatically shuts down the APU only for APU over speed or APU compartment fire
If other FAULT inflight the APU shuts down automatically 10 min after landing
APU master switch
OFF shuts down APU closes inlet door
RUN allows APU to run and opens inlet door
START Momentary Starts APU
Recall when the ignitors operate Auto ON
Autostart,ON idle,one ignitor,cyan,anti ice
Auto automatic start sequence,one or two ignitors for each engine is energized and auto abort feature is operational during start.
Both engine ignitors are continuously on (cyan lightning bolt) if engine ignition is on,fuel switches on, engine at or below idle.EEC will release the start switch and close the start air valve at 39% N2
Auto start (ignition auto fuel on start switch pulled ) uses one ignitor all other modes use 2
In flight Auto or ON positions both provide power to both ignitors during start
During engine operation a cyan lightning bolt is displayed over the tgt digit to indicate ignition is commanded on
The FCC will also command continuous ignition for 60 sec after either ENG anti-ice switch has been selected ON
see autorelight function
How are thrust limits and operating modes displayed
FMS limits and Modes magenta
Manually set white
number of ignitors and how controlled
two ignition units , two igniter leads and tow surface discharge semiconductor ignitors
controlled by EEC each channel of the EEC has capability to energizing either or both ignition units
EEC energizes a single ignition unit during auto start both ignition units for all other modes
if ON then will command both ignitors on if near idle
Auto relight
When ignition is ON the EEC will command both ignition systems on as long as near idle power,
When exceeds idle the EEC will inhibit ignition unless requires ignition by the auto relight logic
EEC provides automatic activation of the ignition system (Auto relight) if
Combustor instability
Significant water/ise ingestion(water detected at HP compressor)
Flameout
Detection of flameout EEC energizes both ignitors and schedules fuel flow until engine relights, following relight the EEC will accelerate the engine immediately to currently commanded power setting, igniters kept energized for 20 seconds after relight. Auto relight is armed when the start is complete
How engine functions controlled from start to shutdown
Full Authority Engine Control(FADEC)
FADEC —throttle,throttle module, EEC
converts pilot inputs into electronic signals to EEC
EEC two channels for redundancy EEC main part of FADEC
APU info
right,800,DC,Batt,2min,17sec,bypassed
Right main tank normally used for APU start
Fuel from any tank can be used via cross feed
when center pumps are used right main boost pumps should also be on . IF center less than 800pounds using center fuel can force air in APU fuel line
If only DC us the start pump
BATT must be on
bleed air inhibited for 2 min
Normal shutdown APU continues to run for 17 sec while electrical system performs no break transfer bypassed when the APU FIRE CONT toggle is moved to OFF and agent armor by the EC following detection of APU compartment fire
How exceedances removed from the EAD
RESET button
engine autostart requirements
ignition switch-Auto
Engine start switch –pulled
Fuel switch–on
reasons for Auto abort
1) Hung start
2) Starter cutout not reached within start duty cycle
180
3)Hot start 700C or rate of increase
4) Fuel on not satisfied
5)Loss of N2 input
6) certain failures of both channels of EEC
Inflight starts
inflight starts are Manual starts not controlled by EEC
AUTO ABORT protections not available during inflight starts
ignitor and channel sequence
alternates EEC channel and ignitor use each auto start.
