Systems Flashcards
What are the hot buses in the airplane?
APU BATT DIR
MAIN BATTERY DIR
DC EMER BUS – includes fire extinguishers
What does the AC ESS XFER switchlight mean if it’s illuminated?
AC ESS BUS is not being powered by AC BUS 1
When would this light normally be on?
AC ESS XFER S/W light
• When you first turn on the Battery Master
• When the ADG deploys
• If you press it to switch the ESS BUS power to AC BUS 2
If we lose AC BUS 2, how many buses do we lose?
AC BUS 2
AC SERV BUS
AC UTIL BUS 1 – losing AC Bus 2 will kick off IDG2, so we’re down to single-gen AC UTIL BUS 2
DC UTIL BUS 1
DC UTIL BUS 2
Both DC TIE 1 and DC TIE 2 would close so that AC BUS 1 can power the left side of the DC system.
What are the conditions under which the AC UTIL buses will load-shed?
Flaps > 0
Single generator
Weight on wheels
Doors closed
What is AC power priority?
Onside generator > APU Gen > Cross-side gen > External AC Power
If the L or R AUTO XFER FAIL switchlight illuminates, what does that mean?
Why might that happen?
There’s been a fault on that AC Bus and the system has inhibited AC power priority.
Short in that bus (AC Bus 1 or AC Bus 2) and system is responding.
Can you re-set it if the airplane inhibits the priority?
fault on that AC Bus and the system has inhibited AC power priority.
No
How would we isolate AC Bus 1?
Press the AC ESS XFER switchlight to transfer AC ESS BUS to AC Bus 2
Press the L AUTO XFER FAIL switchlight to inhibit power priority
Turn the L GEN off. That will isolate the AC Bus 1.
If we turn the L GEN off, can we reverse that?
Yes
What is an IDG?
Integrated Drive Generator
What makes up the IDG?
Generator and the constant speed drive
What happens if an IDG Fault light illuminates?
Indicates HOTLOP (High Oil Temp, Low Oil Pressure)
Would the IDG still be producing power in this case?
Fault HOTLOP
Yes
What would cause the IDG to disconnect automatically?
Overtorque or high case temperature
Can we disconnect the IDG?
Yes, by pressing the IDG switchlight
Can we reverse this?
Pressing IDG switch light and disconnecting IDG
No, it’s not reversible.
When we turn on Battery Master, what is being powered?
“Hockey stick” on DC page:
APU BATT DIR BUS
MAIN BATT DIR BUS
BATT BUS
If you were sitting at the gate, with Batt Master on, what one thing could you immediately do to have the battery power the DC ESS BUS?
Pull the ADG handle (not a good idea)
What is required for ADG deployment?
Parking brake off
Weight off wheels
Loss of all AC power
Last source of power has to have been internal
What’s the difference between EMER POWER ONLY and Loss of all AC Power?
Loss of all AC Power means the ADG didn’t deploy.
EMER POWER means the ADG deploys and we’re using that.
What hydraulic pump can be powered when the ADG deploys?
3B
How many hydraulic pumps do we have on the airplane?
6
How many hydraulic pumps are AC pumps?
4
We’re at the gate prior to pushback. What hydraulic pumps are operating?
3A
Prior to engine start, we put flaps down and we have the APU running. Which hydraulic pumps are running?
3A
Captain starts right engine, flaps are down. What pumps are running now?
1B, 2A, 3A, 3B
After second engine start, flaps down, how many pumps are running?
All Pumps
If we lose the right engine, do we lose any hydraulic systems?
No
What is low pressure in the hydraulic system?
1800 PSI
Which pumps come on when you get low pressure?
None
If we lose Hydraulic Systems 2 and 3, what things do we need to keep in mind when we come in to land?
Brake accumulators will give you up to 6 brake applications.
What’s the biggest hydraulic system on the airplane?
System 3
What kind of cooling does this hydraulic system have?
Ambient air (in MLG bays)
How are Systems 1 and 2 cooled?
Ram air cooling. Also, hydraulic fluid can assist in cooling the casing.
What’s required for the anti-skid system to be armed?
- Arming switch on
• Main Gear down and locked
* Parking brake off
What’s required for the anti-skid to activate?
Weight on wheels > 5 seconds Wheel speed > 35 knots
When will anti skid deactivate?
When speed is below 10 knots
How do we ensure that we accurately check the brake wear indicators?
Hydraulic System 2 & 3 on
Parking brake set
Which hydraulic system operates the landing gear?
System 3
What provides the electronic signal to operate the landing gear?
The PSEU (proximity sensor)
When we pull the landing gear emergency extension handle, what happens?
• Releases pressure in system 2 and 3
• Releases uplocks
• Activates MLG extend assist actuators
How do we stop the main tires from spinning after retraction?
Nosegear relief line applies pressure to stop the spinning
How do we stop the nose tire from spinning after retraction?
It spins itself down.
When we push the ENG FIRE PUSH light, what does that do?
- Shuts off fuel, hydraulics, bleed air SOVs
* Trips off generator
• Arms the squibs on the firex bottles
What areas have detection and firefighting capabilities?
Engines
APU
Cargo
Lavatory
What areas have fire detection only, no extinguishing?
Jetpipe/ pylons
MLG bays
Bleed Air Duct (fuselage up to wing root)
When you run the FIREX test, you are missing a warning message. What does that indicate?
An Open Loop
Can an open loop detect any sort of fire?
Yes, but not in the place where it’s open.
We do the FIREX test and get an APU FIRE FAIL caution. What does this mean?
We have a SHORT/SHORT indication in both APU fire loops, or a NORMAL/FIRE indication
When you push the L ENG FIRE PUSH switch, do any other switches light up?
Both BOTTLE 1/ BOTTLE 2 PUSH TO DISCH light up (green)
Both BOTTLE 1/ BOTTLE 2 PUSH TO DISCH light up (green)
What does this mean?
The bottles are armed and have sufficient pressure.
What do we have in the Cargo compartment as far as fire detection?
2 smoke detectors in the ceiling
If the smoke detectors recognize smoke in the Cargo, what happens?
CARGO SMOKE Caution on EICAS CARGO SMOKE PUSH illuminates Inlet Air SOV shut off Conditioned Air SOV shut off Exhaust SOV shut off Heater shut off Fan shut off
If you press the BOTTLE ARMED PUSH TO DISCHG for the Cargo, what happens?
Both Cargo Firex bottles discharge. One is immediate, one is metered over :45 minutes.
When you turn the Cargo switch from COND AIR to FAN, what happens?
• Heater shuts off
• Conditioned Air shuts off
• Now the cargo only gets recirculated exhaust air from the cabin
What’s the difference between a missing Warning message and a FIRE FAIL message on fire tests?
A missing warning message: You have an open loop
A FIRE FAIL message: There is a short in the loop
When does the aircraft start to automatically balance the fuel?
When the difference exceeds 200 lbs.
How much does the auto balance system transfer?
Until the low tank is 50 lbs higher than the other one.
Can we manually balance fuel? How?
Yes. Select MAN XFLOW and then press the switch on the tank where you want to send fuel to.
Will the fuel transfer do an auto-shutoff in manual transfer mode?
No
When is the Fuel Imbalance Caution message generated?
800 LBs imbalance
Fuel Imbalance Caution message on
If this message comes on, what has probably failed?
The APU / XFLOW pump has failed.
How do the collector tanks get their fuel?
The scavenge ejector sends fuel from the main tanks to the collector tanks
Is there a backup to get fuel from main tanks to collector tanks?
Yes, gravity feed lines get the fuel to the collector tanks.
How does the fuel move from collector tanks to engines?
Main ejectors.
How does the main ejector work?
Motive flow provided by the engine-driven pumps.
If a main ejector failed, how do we get fuel from collector tanks to the engine pumps?
DC Boost Pumps
What conditions need to be met for the boost pumps to come on?
- Pump armed
* Low pressure on that side
If one boost pump activates, what happens to the other?
It also activates
Where do the transfer ejectors move fuel from?
Center tank to main tank
If a transfer ejector fails, what backs that up?
There is no back up other then the other transfer ejector
If both transfer ejectors fail, can we get fuel out of the center tank?
No
Where do the scavenge ejectors get their motive flow from?
Engine driven Fuel Pumps
Where do the transfer ejectors get their motive flow from?
Main Ejectors
How do we transfer fuel from the center tank to the main tank?
We don’t do it manually. It is automatic anytime the main tanks are below 94% full.
At what point does the fuel transfer to the main tank stop?
When the main tanks are back to 100% (4,760 lbs)
We come out to a cold dark airplane with no ground power and APU. What do we have to keep in mind for starting an engine? How do we get fuel to the engines with no power?
Turn on Battery Master
• Ignition B is DC powered off the BATT BUS.
• Left boost pump is DC powered off the BATT BUS. • Need high-pressure air source.
What is the primary purpose of the APU?
Generate AC Power
Before we start the APU, what messages are we looking for?
No APU FIRE FAIL message.
On the DC ELEC page, what messages are we looking for before starting APU (when we turn on battery master?)
- No CHARGER message
* At least 22V on both batteries
When we start the APU, what indications are we looking for after we hit APU PWR/FUEL?
DIGS
Door Open
In Bite
Gauges
SOV open
When does the starter cut out on the APU?
50% RPM