Engines, APU Flashcards
Which system regulates the engine?
A dual channel Electronic Engine Control (EEC) regulates each engine. The EEC monitors auto-throttle and Flight Crew inputs to automatically set engine thrust.
What is the indication an EEC is operating in normal mode?
In normal mode, white ON lights are the only lights illuminated on the associated EEC switch on the engine panel.
What are the indications of EEC hard and soft alternate modes?
- EEC Hard Mode is indicated by the illumination of only ALTN.
- EEC Soft Mode is indicated by the illumination of both ON and ALTN, assuming that the thrust lever has not been retarded to idle.
The EEC’s provide redline overspeed protections for which engine parameters?
The EEC’s provide N1 and N2 redline overspeed protection in both normal and alternate modes.
When do the EEC’s select approach idle for the operating engine?
Approach idle is selected with:
Flaps 15 or greater, or
any time the flaps are extended with engine anti-ice is on.
Approach idle is maintained until after touchdown, when ground minimum idle is selected.
In flight, if a fault prevents EEC from receiving flap or anti-ice signals, approach idle schedule begins <19,000’ MSL
Approach idle improves engine acceleration time in the event of a go-around.
What does the ENGINE CONTROL amber light indicate and when is it armed?
A detection of a fault in the Engine Control System that’s NOT dispatchable.
The light ill’ when:
The engine is operating
and
Aircraft is on the
ground, & below 80 kts
prior to takeoff,
(basically taxiing unless
you’re Southwest)
or
30 seconds after touchdown
(Armed on the ground)
When is the ENG FAIL (amber) alert displayed?
Displayed in the EGT when the engine is below sustainable idle (62% MAX, 50% NG) with the Start Lever in the IDLE position.
The alert remains until:
* The engine recovers.
* The engine start lever
moved to CUTOFF, or
* the fire switch is pulled.
How are the secondary engine alerts toggled?
When the ENG is selected on the Multi-Function Display panel (toggled)
How are EGT redline exceedances indicated?
The digital readout, box, needle and indicator change color to red or amber.
How is an EGT exceedance displayed after engine shutdown?
After engine shutdown on the ground, a box the color of the exceedance (red or amber) will be displayed around the digital readout indicating that an in-flight exceedance has occurred.
How is the N1/SPD REF SET page displayed on the Max Display System?
By selecting INFO on the MFD panel on the forward electronic panel.
What does the THRUST crew alert on the Engine Display indicate?
- indicates engine thrust is more or less than the commanded thrust.
THRUST alert is displayed with the N1 command sector ill’ amber
What are the indications of reverse thrust on the Engine Display?
REV (amber) indicates that the reverser is moving from its stowed position
REV (green) indicates the thrust reverser is deployed
What does selecting FUEL USED display?
Selecting USED will display fuel used since the last reset for 10 seconds, then automatically revert to fuel flow.
What does the illumination of the FUEL FLOW crew alert indicate?
ill’ of FUEL FLOW indicates fuel flow is abnormally high when compared to the FMC expected fuel flow.
What does the illumination of the OIL FILTER BYPASS light indicate?
Appears when there is an impending bypass of the Oil supply Filter.
Which engine start ignitor is available on standby power?
The right igniter plug receives power from the AC standby bus.
Which is why the day is began on IGN R to verify the standby AC bus is properly supplying power to the ignitor
The auto-relight function of the Engine Start System is available when the engine start switches are in which position(s)?
Auto-relight capability is provided for flameout protection with start switch is in ANY position of the start switches
What does MOTORING on the N2 indicator indicate?
Bowed Motor Rotoring straightens the N1 and N2 rotor shafts which will bow due to thermal buildup after the engine is shut down.
BRM is active for 6-90 seconds on ground only. During BRM , MOTORING is displayed on the N2 gauge between 18% to 24% N2
Which start malfunctions do the EECs monitor for during engine start?
- Hot starts,
- Engine Stalls,
- EGT start limit exceedances,
- Wet Starts.
*These protection features do not function during in-flight starts.
How is an impending hot start indicated during engine starting?
If an impending:
*hot start is detected by a rapid rise in EGT or EGT approaching the start limit
or a
*compressor stall occurs, the white box surrounding the EGT digital readout flashes white.
The flashing white box resets when the start lever is moved to CUTOFF
What does the illumination of the REVERSER LIMITED light indicate?
In flight:
-A fault in the thrust
reverser system
limits reverser thrust.
* The thrust reverser will not deploy or reverse thrust will be limited to idle if commanded.
-On the ground:
* A malfunction has occurred.
What does the illumination of the REVERSER COMMAND light indicate?
The reverse thrust lever is not in the down position in flight.
What does the APU provide?
Bleed air for air conditioning and starting the engine.
Auxiliary AC power for the aircraft.
Does the APU require the BAT switch to be on to operate?
yes
As well as APU fire switch on overheat/fire panel must be IN
APU fire control handle on the APU ground control panel must be IN
BAT switch must be ON
How long should the APU run after illumination of the APU GEN OFF BUS (blue) light before opening the APU bleed valve?
A full 2 minutes
This extends service life of APU
How long should a pilot wait after the APU switch is selected OFF before selecting the BAT switch OFF?
5 minutes for the MAX,
2 minutes for the NG.
Allows adequate time for APU inlet door to fully close
What will cause the automatic shutdown of the APU?
- RPM overspeed
- Low oil pressure.
- High oil temperature.
- APU fire.
- Fuel Control Unit failure.
- EGT exceedance, and
- other system faults
monitored by the ECU.
