7 Engines Apu Flashcards
Primary ENG indications
Secundary ENG indications
N1, EGT, fuel quantity
N2, fuel flow, oil pressure, oil quantity, eng vibrations
Thrust modes
To - take off
To 1/2 - derated t/o 1/2
D-to - derated t/o assumed temp
D-to 1/2 - derate 1/2 and assumed temperature reduced t/o thrust
Crz
G/a
Clb - climb
Clb 1/2 - derated climb 1/2
Right box egt turning red
Small 🔴 egt line
At the end of EHT 🔴 egt line
-In flt exceedance, when on ground and eng shut down, when ENG limit exceedance. Max t/o / start limit exceedance.
- egt start limit redline
- max t/o egt, or max inflight limit when no start limit redline
EGT 🟡 circle
Max cont limit exceeded, inhibited when:
- color change (to amber) inhibit up to 5min during T/O or GA
- when ENG out conditions occur during the 5 min, color change inhibited for 10min
🟡 ENG FAIL (in egt)
-When ENG START LEVER at IDLE D.
- N2 below sustainable IDLE (50%N2)
Remains amber until:
- N2 recovers
- ENG STAR LEVER CUTOFF
- ENG fire switch pulled
🟡 START VALVE OPEN
- ENG START VALVE OPEN and air is supplied
- Blinking for 10 seconds when START VALVE OPEN uncommanded (than steady)
Blinking inhibited:
- during t/o from 80KIAS to 400’RA or 30 sec after reaching 80KIAS, whichever occurs first
- during landing below 200’ RA until 30 sec after touchdown
- when inhibited: illuminates steady
LDU comes on
- ENG FAIL/SHUTOFF
- secondary ENG parameters exceeds normal operating range
- when CDS initially receives power
- when selected
🟪 X-BLD (at N2)
Crossbleed air recommended for inflight start
-displayed when airspeed is less than required for windmilling start
🟦 Oil Pressure
🟦 Oil Quantity
Low oil pressure caution range is variable depending on N2 RPM above 65% N2
🟧 Band is NOT displayed below 65% N2
In Quartz, box will be white in stead of black when Low Quantity
ENG START SWITCH
OFF
CONT
FLT
Will be OFF during flight, it (L and R) will activate automatically when ENG start lever in IDLE and:
- uncommanded rapid decrease in N2
- N2 from 50%-57%
- In FLIGHT N2 between IDLE-5%
CONT:
- provides ingition to selected igniters when ENG operating and ENG START LEVER at IDLE
- IN FLIGHT - provides ignition to BOTH ignitors when N2 is below IDLE and ENG START LEVER at IDLE
FLT: provides ignition to BOTH ignitors when ENG START LEVER at IDLE
🟡 ENGINE CONTROL
🟡 REVERSER
NOT dispatchable due to faults in system, illuminate when:
- engine is operating and,
- airplane on ground and,
Below 80KTS prior to T/O
Approx. 30 sec after touchdown
Illuminate when one or more of:
- isolation valve or thrust reverser control valve is not in commanded position
- one or more thrust reverser sleeves are not in commanded state
- auto-restow circuit had been deactivated
- failure detected in synchronization shaft lock circuitry
EEC
ON
- ENG ratings calculated by sensed atmospheric conditions and bleed air demand
- when ON NOT illuminated, the ALTN mode has been manually selected (hard)
- when ON + ALTN on: soft alternate mode (automatically)
EEC becomes powered after the Engine accelerated to a speed greater than N2.
Normal mode; EEC compares commanded N1 to actual N1 and adjusts fuel flow.
When HARD ALTN mode: provides equal or greater thrust than normal mode for same lever position. max thrust rating is reached before throttles are fully forward ( you have no protection)
ENG START LEVER IDLE
- energizes ignition through EEC
- Engine fuel/spar valve Shut Off valve opens
When turned to CUTOFF, opposite
APU switch to OFF
🟦 MAINT
🟧 LOW OIL PRESSURE
🟧 FAULT
🟧 OVER SPEED
Switched off: off busses (trips), bleed air valve closes. After 60 seconds (cool down) and APU shuts down automatically. When APU speed decreases sufficiently during shutdown: air inlet closes (20 sec), fuel valves closes
ALL LIGHTS DISARMED WHEN APU SWITCH IN OFF POSITION
🟦 MAINT
- APU problem exists
- apu may be operated
🟧 LOW OIL PRESSURE, after start cycle complete:
- low pres causes autoshut down
- light illuminated when APU switched off: stays illuminated for 5 min
🟧 FAULT
- malfunction causes auto shut down
- light illuminated when APU switched off: stays illuminated for 5 min
🟧 OVER SPEED
- RPM limit exceeded: auto shut down
- overspeed protection feature failed a self-test during normal APU shutdown
- light illuminated when APU switched off: stays illuminated for 5 min
EEC Overspeed protection
Approach IDLE
N1 and N2 redline overspeed in both normal and alternate modes. But EGT MUST be observed by crew, EEC does not provide EGT redline exceedance.
Any of following conditions are met:
- cowl thermal anti-ice switch is ON for either 1 ENG or 2 ENG
- Altitude is below 19.000’ AND L or R main landing gear is down + locked
- Altitude is below 19.000’ AND L or R flaps are in approach config (same or higher than F15)
Fuel flow measuring
After ENG FUEL SHUTOFF VALVE
ENGINE EEC + igniter plugs
Each ENGINE:
- 1 EEC with 2 channels
- 2 igniter plugs
L igniter powered by AC transfer bus
R igniter powered by AC Standby bus
ENG START OPS
Starter motor
ENG START SWITCH GND
25% N2/ max motoring
Starter motor powered by bleed air
GND: battery power to close ENG bleed air valve + opens the start valve
56% N2: opposite
25%: Eng Start Lever to IDLE DETENT, opens fuel valves and causes EEC to supply fuel and ignition (fuel flow indications lag by 2seconds)
Abnormal start protection ( GND ONLY)
Ground starts: EEC monitors engine parameters to detect impending:
hot starts: [rapid rise in EGT or EGT approaching start limit or compressor stall occurs]
- EGT box flashes white until ENG START LEVER CUTOFF or N2 at IDLE
- auto turn off the ignition and shuts off fuel to engine for impending hot start or stall
wet starts: [no EGT increase after ENG start lever IDLE DETENT]
- EEC turns off the ignition and shuts off fuel to the engine 15 seconds after ENG START LEVER switch to IDLE
EGT Starter Limit exceedance:
- both box and dial turn red
- EEC turns off the ignition and shuts off fuel to engine.
|- alert terminates and the display returns to white when EGT drops below the start limit
- following shutdown of both engines, EGT box turns red to remind the crew of exceedance
Auto-relight
Provided for flameout protection
- when EEC detects ENG flameout, both ignitors activated.
- flameout is detected when an uncommanded rapid decrease in N2 occurs or N2 below idle RPM
Reverse thrust
-available
- stowed
Available: RA below 10’, forward thrust levers in IDLE position and ground/air sensors sense ground mode
Stowed: the REVERSER light illuminates when thrust reverser is commanded to stow and extinguishes 10 seconds later when isolation valve closes. When REVERSER light illuminates for more than 12 seconds, malfunction has occurred and MASTER CAUTION and ENG system light illuminate.
When reverser sleeves in stow position, an electro-mechanical lock and a hydraulically operated locking actuator inhibit motion to each reverser sleeve until reverser extension is selected.
AVM
Airborne Vibration Monitoring System
function: display of low and high pressure rotor synchronous vibration of the secondary engine display. Also used to balance the low pressure rotor.
APU
- supply
-operating requirements
-powered
- supplies bleed air for both packs on ground or one pack in flight
- app fire switch must be IN
- APU fire control handle on APU ground control panel must be IN
- Battery switch must be ON
- Powered from Transfer bus 1, if no AC power available: the starter generator uses battery power to start the APU. (BAT switch off: APU off)
APU
- Start cycle
-switch off
- auto shutdown
- may take as long as 120 seconds (0 to 1100 degrees EGT), when operating wait 2 minutes before using it as bleed air source
- Trips APU generator, closes APU bleed air valve, shutdown occurs after 60 seconds: fuel valve + inlet close.
When fuel valve doesn’t close FAULT LIGHT will illuminate after 30 seconds. - EGT exceedance, auto shutdown.
ECU
- automatic shutdown
- FAULT LIGHT, OVERSPEED LIGHT, LOW OIL PRESSURE LIGHT (and the conditions)
APU Load shedding
when apu only source of electrical power:
- in flight
- on ground
in Flight: sheds galley power + main busses
on ground: attempts to carry all load. If no sufficient power: It will shed the galley power. No sufficient power? Main busses will be shed.
- manual restoration: CAB/UTIL switch off to ON
