Mock Oral Flashcards
How would service employees get lights to service the aircraft?
External service button on the AC service panel
Where is the AC service panel located?
Forward right fuselage
What bus does the AC service switchlight power?
AC service bus
What kind of things are on the AC service bus?
Lights
Water & waste control
What does the DC service switch get power from and what does it power?
APU Battery Direct Bus
Service bus
What does the AC & DC service switches power?
AC & DC service buses
Which buses are always powered (hot)?
APU Battery Direct Bus
Main Battery Direct Bus
Emergency Bus
What are ways the AC system can be powered?
IDG
APU
ADG
AC External Power
What happens when I switch the battery master on?
The BATT BUS is powered by the APU Battery Direct Bus & the Main Battery Direct Buses. The DC system is turned on
What other switches on the aircraft can control DC systems?
None. The DC system is taken care of by DCPCs
What are the two ways the DC system is powered?
Main & APU Batteries
TRUs (this is the long term way it will be powered)
What buses power the TRUs?
AC Bus 1
AC Bus 2
AC Bus 2
AC ESS Bus
What controls all of the bus ties?
DCPC
In default the cross ties are all ____.
Closed because they are all powered by the TRUs.
If AC Bus 1 failed, which tie would open?
Main tie
Utility bus would be depowered
The ____ will automatically control the ties to optimize power to the DC system.
DCPCs
If we lost all AC power what would happen?
ADG would deploy
Would the ADG power the DC system?
Yes because the AC ESS Bus is powered, so that TRU will convert it to DC. The ESS tie will connect it to the BATT BUS
AVAIL on the AC Service switchlight means we have the correct voltage, frequency, and phase from
The AC external power
What’s the sequence of events on the AC Service switchlight?
AVAIL will illuminate when we have the correct voltage, frequency, and phase (115V, 400HZ, 3 Phase). Then you hit the button for the AC external power to become IN USE.
If we had AC External power IN USE and we turn on the APU, what would be powering the airplane?
The APU because it’s priority (onside, inside, cross side, outside)
With GEN 1 & the APU on, what is powering what buses?
GEN 1 is powering BUS 1 & the APU is powering BUS 2
What are the components of an IDG?
Constant speed drive & a generator
When would we press a guarded switchlight?
When directed by the QRH
If the IDG FUALT light is on, what has happened to your electrical system?
FAULT light means high oil temperature, low oil pressure. Nothing because the IDG hasn’t failed yet, it’s just showing a fault. In order for the IDG to be taken offline, DISC switchlight needs to be depressed
For mechanical shearing of the IDG would you get the DISC light?
No. The DISC light means the selected disconnect was successful
ALTN illuminates on AC ESS XFER Switchlight. What does that mean?
Per the electrical systems manual, the ESS BUS is now being powered by BUS 2
What is normally powering the AC ESS Bus?
BUS 1
What else can power the AC ESS BUS?
BUS 2, ADG, External power
What is powered by the ESS BUS? (Same things that ADG powers)
Stab trim CH 2
Slats/flaps
HYD System 3
If the FAIL portion of the GEN 1 AUTO XFER switchlight illuminates (the GCU has detected a bus fault or overcurrent) GEN 1-BUS 1 will be isolated from the system. If this happens, is there any way to get BUS 1?
The IDG has to be reset by maintenance but Bus 1 can be powered by the APU, GEN 2 & AC external power.
AUTO XFER FAIL switchlight is not illuminated but something on BUS 1 is causing a spark. How would you manually get rid of BUS 1?
Press GEN 1 AUTO XFER OFF. This will isolate GEN 1 & Bus 1 from the system
If you select GEN 1 AUTO XFER OFF and decide you want GEN 1 & BUS 1 back online, can you get them back?
Yes, because it hasn’t failed, it’s been selected off
Before turning on the APU, you have to do the _____ test.
Fire Detection
What type of message is FIRE SYS OK?
Advisory
How many fire/overheat detection loops are on the plane?
Dual loops: 2 Engines, APU (6 loops)
Single loop: 2 MLG Bay (2 loops)
8 loops total
Indication of an engine fire?
Triple chime
Master warning flasher
EICAS message (L/R engine fire)
ENG FIRE PUSH Switch illuminates
What would pushing the ENG FIRE PUSH switch do?
Close bleed air, hydraulic, and fuel SOVs
Arm the squibs
Take the generator offline
5 seconds later, if the engine fire indication is still there, do what?
Hit the BOTTLE ARMED PUSH TO DISCHARGE for the associated engine
If that bottle didn’t put the fire out, can you use the other bottle on the same engine?
Yes. When you press the ENGINE FIRE PUSH switchlight, this indicates to the system which engine is on fire, and the bottles will be discharged into this engine
Running APU on the ground and it catches on fire, what would happen?
Fire bell, master warning flashers, APU FIRE PUSH switchlight will come on. APU would be taken offline, after 5 seconds, if fire is still there after shutting the APU down, bottle will automatically discharge. If the fire goes away after the APU shuts down, it will not discharge the bottle.
How many bottles are there for the APU?
1 bottle
How many cargo bottles are there?
2
If the FWD CARGO SMOKE PUSH switchlight illuminates and we push the BOTTLE ARMED PUSH TO DISCHARGE switchlight, what will happen?
2 bottles will be discharged into the FWD cargo compartment
Pushing the AFT CARGO SMOKE PUSH switchlight will
Arm the squibs
Shuts the recirculation valves
Why do the B pumps kick in when the flaps are out of zero?
The system knows you’re about to takeoff or land. Need hydraulics for gear
When would you get a HI HYD TEMP EICAS message?
96 degrees C
What HYD system operates inboard brakes?
HYD system 3
What HYD system operates outboard brakes?
HYD system 2
What cools the HYD system 1 & 2?
RAM air/oil heat exchanger (oil here means HYD fluid)
What cools HYD system 3?
It is not near anything critical like an engine or fuel so it just cools down on its own.
What HYD system powers alternate gear extension?
HYD system 2 (MLG AUX ACT)
How do we make HYD system 2 drive the alternate landing gear down?
LG PULL lever
Speed limit on alternate landing gear extension?
220 KTS
We lose HYD system 3 and manually extend the landing gear using the lever and HYD system 2. We land and want to taxi off the runway. Will we be able to?
No, because N/W STEER is on HYD system 3 which has failed
How many fuel pumps are in the fuel system?
6. 2 engine driven pumps (invisible on SYN) 2 boost pumps Crossflow pump APU pump
How many ejector pumps are there in the fuel system?
8 (only 6 depicted on SYN)
2 transfer
4 scavenge
2 main
What would the normal configuration of the fuel panel look like? What lights would be on normally?
None.
How does AUTO XFLOW work?
When the system detects an imbalance of 200 lbs it’s going to automatically direct fuel into the low tank until its balanced +50 lbs
If AUTO XFLOW failed, when would you select a different mode?
When directed by the QRH
If the QRH directed you to try MAN mode, how would you do that?
Hit MAN XFLOW AUTO OVERRIDE switchlight then the L or R button depending on which tank you want fuel to flow into
When would MAN XFLOW turn off?
You have to turn it off yourself so you have to watch quantity
What happens during GRAVITY XFLOW?
Gravity crossflow valve opens and allows the system to balance itself out.
How do we select GRAVITY XFLOW?
Hit the OPEN switchlight
What if you open the valve and everything is balanced and looking good, and you hit the button again to close the valve and you get a FAIL light?
The valve is not in the commanded position
Pushing the L or R BOOST PUMP switchlight does what?
Arms the boost pumps
When in normal operations would you push the BOOST PUMP switchlights?
To start the engines
After starting engines, BOOST PUMPS are only needed to back up the main ejector. Will the BOOST PUMP switchlight say ON at this point?
No, it will only be armed, not ON because the main ejectors are outputting enough fuel pressure
When would you get an EICAS message that says AUTO XFLOW INHIBIT?
When the plane is being refueled
How does the fuel get from the center tank to the engines during normal operations?
Center tank Transfer ejectors (backed up by opposite ejector) Main tanks Scavenge ejectors (backed up by gravity) Collector tanks Main ejectors (backed up by boost pumps) Engines
What drives motive flow through all of the ejector pumps?
Engine driven fuel pumps
If the engine driven fuel pump fails, will the engine stay on?
No
When would you turn the BLEED AIR WING A/I CROSSBLEED knob?
When directed by the QRH
If you lost your L engine, what would the QRH have you do with the BLEED AIR WING A/I CROSSBLEED knob?
FROM RIGHT
What would the valves do in this configuration? (crossbleed FROM RIGHT)
Wing anti ice crossbleed valve would open (top valve)
L valve would close
R valve would open
What valves does the BLEED VALVE knob control?
Look on ECS SYN.
PRSOVs for the engines
APU valve
XFLOW valve
In auto, what happens to those 4 valves?
It automatically controls the valves. For example, if APU is on it’s going to shut off the engine valves and provide bleed air from the APU.
In the CLSD position, what are the valves going to do?
Engines and APU valves will be shut off
If the engines and APU are turned off, is there any other way to get air to the system?
External air (powers the PACKS and pressurization)
When would we select BLEED VALVES in manual?
When directed by the QRH. Configure the panel before selecting MANUAL
If your BLEED VALVES are in manual, the ISOL valve is CLSD, and the BLEED SOURCE is the APU, what PACK could be powered?
PACK 1
If AVAIL is illuminated on the APU START/STOP switchlight, do you have to do anything more to get power from the APU?
No. Means the APU is currently in use
APU load control valve is a ____ valve
Bleed air
Which gauge are you looking for the APU starter to cut out by 60%?
APU RPM gauge
How do we do a bleeds closed takeoff?
Turn APU on (for AC & pressurization)
