KV SYSTEMS PREP Flashcards
What powers the 2 EICAS screens?
Battery Bus
What do red, amber, green, and white EICAS color codes mean
red - warning
amber - caution
green - advisory
white - status
Are the 2 EICAS cooling fans powered by the battery bus?
No
Why is it important to provide APU/External power to the aircraft within 5 minutes of energizing battery?
To prevent EICAS screens from overheating (will have no cooling fans)
What gathers data for EICAS display?
2 DCUs (data concentrator units)
How many chimes for a caution and warning?
Caution = 1, Warning = 3
What other aural warnings can DCU generate?
Fire bell (fire), warbler (stall), clacker (overspeed), siren (windshear and terrain)
Which aural warnings will DCU audio warning inhibit switches not cancel?
Windshear, EGPWS, and TCAS
Which 4 ECP buttons are mechanical and not dependent on ECP microprocessors or ECP power?
PRI, STAT, CAS, STEP
When will oil pressure gauges be present on primary display in addition to the digital readout?
With engines shutdown or with low oil pressure
When will N1 vibration gauges replace oil gauges?
With engines running and normal oil pressure
How is N2 vibration monitored?
System monitors N2 vibration independently without display. If N2 vib exceeds a predetermined amount, VIB will be displayed inside the N2 gauge.
When will flap gauge disappear?
With wheel brake temps normal range, and gear/slats/and flaps retracted.
When will brake temp indicators disappear?
Temps in normal range and gear/slats/and flaps retracted.
When can you box caution messages and how?
Pressing CAS with both engines running. New messages will appear above boxed MSG icon.
When are certain caution messages inhibited on takeoff?
Thrust lever advancement to 400 feet
When are certain caution messages inhibited on landing?
400 agl to weight on wheels + 30 seconds, or when climbing above 400 feet (go around)
What will happen if ED1 fails?
Primary page will auto revert to ED2
If ED1 fails, and primary on ED2, how can synoptic pages be viewed?
Select EICAS on MFD reversionary panel and use the ECP (EICAS control panel) to cycle through synoptic pages
Name several conditions that must be satisfied for TAKEOFF CONFIG OK message
Parking brake off, flight spoilers stowed, flaps between 8-20, stabilizer trim inside green takeoff band, rudder trim inside takeoff range, aileron trim inside takeoff range, auto pilot off
(J*) If many messages received at once on EICAS, it no longer lists in order of importance. What order should you use?
(EL HYPO) EL = electric HY = hydraulic P = pneumatics O = other
When will the ED’s (1 or 2) auto transfer if you have a failure of one or the other?
Only auto transfer if you have failure of ED1 (ED1’s primary page would then go to ED2)
Give a brief description of the EICAS:
- Consists of 2 displays (ED1 and 2)
- 2 DCUs (data concentrator units) process data from aircraft sensors for display on EICAS
- DCUs then pass data to LDU (lamp driver unit), which signals the operation of the switchlights located through the cockpit
Give a brief description of the powerplant:
- 2 high bypass turbofan engines provide thrust
- each engine controlled by FADEC
What are variable geometry vanes?
- Used in compressor section of engine to optimize engine airflow and protect against compressor stall.
- VG movement is controlled by FADEC.
- Inlet guide vane and the 1st 4 stages of the engine include the VG vanes.
About what percentage of airflow is bypassed in engine (provided by N1 fan)?
approx 80%
Describe the airflow of the engine vs. the APU
Engine = axial flow, APU = annular flow
Where is ITT measured?
2nd stage high pressure turbine
What is the job of the 2nd stage high pressure turbine?
To drive the compressor section
What drives the N1 fan?
4th stage low pressure turbine
What drives the accessory gear box?
N2 compressor, which is driven by the high pressure turbine.
What items are on the accessory gear box?
Hydraulic pump, fuel pump (3), oil pump, FADEC alternator, integrated drive generator (IDG), and air turbine starter
How does reverse thrust work?
Uses bypass air, 3rd section of engine cowling, vanes angled forward, and blocker doors block airflow.
What stage does bleed air get extracted from?
6th stage, unless 6th stage is insufficient - then uses 10th stage bleed air into manifold
What allows us to obtain proper fuel flow automatically?
FADEC commands the fuel metering unit for target fuel flow
What is the function of the operability valve?
- Located at 10th stage valve, works in conjunction with VG vanes
- If too high a pressure is created, it acts as a block
- This helps prevent compressor stalls by dumping bleed air pressure off of the section
- All done automatically
Can engines run with out FADEC?
No
Does the APU or crossfeed start have to go through PRSOV?
No
What is the function of the fuel/oil heat exchanger?
Use engine oil to heat engine fuel and uses cold fuel to cool fuel
(*J) Can you use APU bleed air for anti-icing?
No
What are 2 things that occur during flameout protection?
FADEC will auto detect and initiate a relight and N2 would spool unless something stopped it.
What is continuous ignition?
When ignition A and B are both energized. The only time all 4 come on at once is with manual selection.
(*J) What are the conditions to keep N1 synced?
Must be within 1.5% and within 2.5% for N2 sync
What 3 interconnected fuel pumps are within the accessory gear box?
Low pressure, high pressure, and motive flow pump
What are the rated thrust outputs of the engines?
700 and 900 have same engine, but 700 is downrated to 12,670lbs T/O thrust and 13,790lbs APU thrust
What powers the VG vanes?
Fuel pressure directed by FADEC
What powers the operability valve?
Fuel pressure directed by FADEC
How many channels does FADEC have and when do the channels change?
2 channels (A and B). Change when N2 rpm falls below 7% on every OTHER engine shut down.
How many FADEC channels are used at once?
1 channel commands the engine while the other channel monitors the controlling channel and is in standby in the event the commanding channel fails
Is there ever a time when both FADEC channels will command the engine simultaneously?
In engine overspeed situation both FADEC channels will command the fuel valves to close to bring speed into the normal range
Can the left FADEC control the right engine?
No
Do the R and L engine’s FADECs cross talk with each other?
Yes, they compare engine speed and thrust reverser position info
When an engine fails, what will the operating engine’s FADEC automatically command?
APR in TOGA detent, MCT in CLIMB detent, and a proportionate increase throughout the cruise range
What powers the FADEC?
Aircraft electrical power with an N2 of less than 50% and the FADEC alternator with and N2 greater than 50%
What is FLEX thrust?
A reduced power setting for takeoff calculated using an assumed temp
Which stages of the engine is bleed air extracted from?
6 and 10 but not both at the same time
What powers the igniters?
Igniter A is powered by AC Essential Bus. Igniter B is powered by aircraft’s battery and an inverter
When will continuous ignition fire automatically?
FADEC senses a flameout, approaching a stickshaker during stall, and disruption of airflow is detected through the engine
How are thrust reversers actuated?
Hydraulically
(J*) What is the primary purpose of the APU
To provide electrical power
How many kva from APU?
40
What can APU bleed air be used for?
Starting and air conditioning
What tank does APU pull fuel from?
Left collector tank
Will APU shut down on ground due to HOTLOP?
Yes
What is the reason behind the APU door open in flight/unknown position speed limitation?
Prevents APU from windmilling and to ensure rpm remains low enough to start the APU if necessary
If APU fuel pump fails, will APU continue to operate?
Yes, but it cannot be restarted without the pump.
What is the purpose of the LCV (load control valve)?
Varies pneumatic load from APU to ensure electrical power and 45 psi in the manifold
Min battery voltage for APU start?
22 volts
What powers the APU door?
APU battery provides power to the door and is secondary for the ECU. Main battery is primary power source for ECU
If APU is left unattended, can ground crew shut it down?
Yes, through APU shut off switch on forward nose, or in APU compartment
In the bleed air system, all valves are electrically controlled and pneumatically operated except for ?
ISOL valve and wing anti ice valve (both electric)
Which anti ice SOVs fail open?
Cowl anti ice SOVs
Which anti ice valves fail in the position they were in?
ISOL valve and wing anti ice (bc electric)
What controls the amount of bleed air from the APU and fails safe closed?
LCV (Load Control Valve)
(J) For low pressure AC on the ground, what 2 doors must be open?*
Avionics bay door and Front Pax Door
What happens when cabin alt reaches 8500 ft?
Amber message (caution)
What happens when cabin alt reaches 10,000 ft?
Red message (warning)
If the seatbelt sign is in auto, at what cabin alt will CPAM automatically turn on seat belt sign?
10k
What happens when cabin alt reaches 14,000 ft?
Mask drop
Brief description of pressurization schedule:
- This is a region of flight abort capability
- When advance throttle for TO, cabin alt drops to -150 below field ele
- Climb mode = cabin climbs at 350 fpm
- If in the first 10 mins of flight, you don’t reach 10k feet, it will auto reach field elevation pressure for cabin
Above what altitude can we not use the EMER DEPRES button?
Greater than 15k
When bleed air comes from engine, what psi is pressure reg function?
45 +/- 3
Left pack and right pack primary?
Left = cockpit, right = cabin
Why is it considered standard practice to use the rotary dial for temperature changes?
With the rotary dial, we have overheat protection. (Only use manual mode if qrh directed as this can overheat pack)
When would amber fault light illuminate on pack?
Over temp or over pressure
Which cargo has temp control?
Aft
When we use cargo fan, we also arm what?
A heater
How many outflow valves do we have? (pressurization)
1 with 3 DC motors
How do you know if you are using pressure control?
Says on ECS page
What does switching the DC Service switch to ON do?
ON: Connects the DC Service Bus to the APU BATT DIR BUS
What does switching the BATTERY MASTER switch to ON do?
ON: Connects the APU and MAIN BATT DIR BUS to the Battery Bus.
(Remember the 5-minute limitation on the EFIS for no AC Fans being powered)
-22V minimum on both buses when powered on
When the AC External Power Switch is in AVAIL what does this mean?
AVAIL: When external power is connected and is ready to use.
When does a FAULT light (amber) illuminate on the IDG 1 or 2 DISC Switchlight?
Whenever there’s a low oil pressure or high oil temperature.
IDG will automatically disconnect when an over-temp or over-torque condition occurs. IDG cannot be reconnected in-flight needs to be done by maintenance.
What does pressing the AC ESS XFER button do?
Pressing switches the essential bus feed from AC Bus 1 to AC Bus 2. The transfer is automatic during an AC Bus 1 failure.
When you select the generator to AUTO what happens?
AUTO- Connects the generator to the associated bus.
“System Logic” “Bus Priority”
What is the AUTO XFER Switch used for?
OFF: Indicates auto-transfer is selected off
FAIL light (amber): Indicates a fault preventing auto-transfer
Used to isolate a bad generator.
When doing a fire test (TEST SWITCH) what’re you checking?
Testing the FIREX System.
What does selecting the HYD SOV do?
Closes the hydraulic shutoff valve. Can aid in a hydraulic leak.
QRC/QRH Driven
What does turning on the NAV lights do?
Illuminate the red, green, and white position lights.
NAV light remains ON at all times
What does turning on the Beacon lights do?
Illuminated red beacon lights on the upper and lower fuselage.
What does pressing in the BOOST PUMP switch light do?
- Engine Start boost pump is activated
- Pump is armed and will operate automatically when low fuel pressure is detected in any engine feed line.
Switchlight illuminates ON when the pump is operating.
When will cabin control pressure 1 automatically switch to CPC2?
3 mins after landing
If you had a fault in cabin control pressure 1, how do you manually switch to CPC2?
Pushing pressure control button x2
What is CPAM?
Cabin pressure acquisition module (aka microprocessor)
CPAM sends a message to what to alert of cabin pressure abnormalities (8500, 10k, 14k)?
DCU
What 2 safety valves does the pressurization system contain?
- over pressurization safety valve - opens at 8.7psi
2. negative pressure relief valve - opens at -.5
How does air from packs get into passenger compartment?
Conditioned air from both packs is sent to mixing manifold under after cargo floor, then routed to flight deck and pax compartment.
Ram air functions:
- Helps cool packs by passing through the pack heat exchangers then exiting overboard
- If both packs fail, can be used as sole source of ventilation
- Hydraulic sys 1 and 2 are cooled by ram air
Describe the flow of air through the pack components:
(“Please Hand Charlie His Red Coat With Tails”)
Precooler, Heat exchanger, Compressor, Heat exchanger (secondary), Reheater, Condenser, Water extractor, Turbine
How is bleed air from both engines kept separate?
Isolation valve
Can left engine provide bleed air to right pack?
Yes, by selecting ISOL switch to OPEN, and BLEED SOURCE rotary selector to L ENG, and then placing BLEED VALVES rotary selector in MANUAL
Can the aircraft be flown with 1 pack inop?
Yes, but limited to 31k feet
What is max differential pressure during taxi?
.1
When does bleed air switch from APU to engines?
After TO, when thrust levers are pulled out of TOGA detent, with gear up, and flaps 20 or less.
When does bleed air switch from engines to APU on approach?
With gear OR flaps extended to 20 or greater, with thrust out of TOGA.
What manages bleed air distribution and the air conditioning system?
2 ACSCs (air conditioning system controllers)
What is the water extracted from the pack used for?
It is sprayed across the pack heat exchangers in the ram air duct for cooling
How many recirculation fans are there?
2 fans, 1 switch
Describe the journey of air from outside aircraft, through, and back out:
- Air first enters the engine
- Then ducted to the packs as hot bleed air
- From packs, it enters the cabin as conditioned air
- From cabin, it exits outside through the outflow valve
What is the function of PRSOVs? (pressure regulating shut off valves)
Modulate as commanded by ACSCs to maintain approx 45 psi +/-3 in the bleed air manifolds
Describe the flow of air through the pack components:
(“Please Hand Charlie His Red Coat With Tails”)
Precooler, Heat exchanger, Compressor, Heat exchanger (secondary), Reheater, Condenser, Water extractor, Turbine
What happens when the fuel pump is pressed out?
The boost pump is disarmed.
Which engine bleed air stage does hot anti ice come from?
10th stage
How do the ice detectors detect ice formation?
They vibrate constantly, will detect ice because when it forms it will slow the vibrate. Will heat 5 seconds on, 55 seconds off to regain vibrate and ice detecting ability
What action should we take if we receive amber ICE message?
Turn on all anti ice. ICE message will turn to green once all anti ice on
Speed limit for wing anti ice
230
When looking on EICAS synoptic page and the N2 setting is white and aircraft wings are white, what does that mean?
Need higher N2 to turn green
When do we turn windshield heat to high?
Only when ice formation seen on windshield. (High turns shields high and side windows low)
ISOL Switch does what?
OPEN- Opens the valve to allow crossbleed
CLSD- Isolates both systems
Which probe is the only one not heated on ground?
TAT
Which probes are heated when probes ON on the ground?
Pitot heat in full, S3, and AOA
The wings and engine cowls are heated by __ bleed air
Engine
External probes and the cockpit windshield are heated ___
Electrically
How is wing anti ice system controlled?
Wing anti ice is manually activated then automatically controlled by the dual channel anti ice leak detection controller (AILC)
How are the anti ice bleed air ducts designed to protect from leaks?
- Ducts are double walled with bleed air passing through inner portion of duct
- If there is a leak in inner wall, bleed air will escape to the outer duct, and the AILC will detect the leak
- The double walled ducts are only for cowl anti ice. They wing anti ice ducts utilize the double loop detection system
Are vertical and horizontal stabilizers provided with anti ice protection?
No, anti ice is not required for these surfaces bc tests have proven no significant ice can from there
Which engine bleed air stage does hot anti ice come from?
10th stage
What happens when you OPEN the GRAVITY XFLOW switch light?
The gravity SOV opens, when pressed out the gravity SOV closes.
FAIL- Occurs when the SOV is not in the commanded position.
How can external power be used by ground crew when cockpit door is locked?
Press AC PUSH switch light on external service panel
What does pressing in the XFLOW AUTO OVERRIDE?
Pressed in: Crossflow/APU pump is armed for manual crossflow.
When selecting the WING A/I CROSS BLEED Selector?
FROM LEFT: The wing cross bleed valve is open and the right-wing anti-ice valve is closed. FROM RIGHT is the same besides the left-wing anti-ice valve is closed.
NORMAL: The wing cross bleed valve is closed.
What does the BLEED VALVES Selector do?
CLSD: Closes all bleed sources and must be used when using an external ground source to prevent damage to the engines or APU.
AUTO: Controller manages system requirements
MANUAL: Allows manual configuration of the system.
ISOL Switch does what?
OPEN- Opens the valve to allow crossbleed
CLSD- Isolates both systems
PWR FUEL Switchlight gets pushed in what should display?
DIGS
APU DOOR OPEN
APU IN BITE
GAUGES DISPLAY
SHUT-OFF VALVE OPENS
(APU Fuel Pump is energized, the APU fuel feed shut-off valve opens.)
What items are on utility bus?
Passenger service units - mainly reading lights
CONT ignition switch light will automatically illuminate when what conditions are met:
Activates when a stall is detected, regardless of the switch position.
Are the wings protected from getting too hot?
Yes, the anti ice leak controller (AILC) monitors wing temp, and regulates the anti ice valves to maintain the appropriate temp
Can 1 bleed provide air to both wings?
Yes, by opening WING A/I CROSS BLEED selector to the desired state
What do probe switches do in flight?
Nothing, in flight all probes are fully powered regardless of switch position
Hydraulic Pump 2B POSITIONS (AC Motor Pump 2B Switch):
ON- Pump will operate at 3000 +/- 200psi output
OFF- Pump is not operating
AUTO- Pump will operate in AUTO position when the flap setting is greater than 0-degrees and the AC Bus 1 powered.
What are the 2 subcomponents of IDG
Constant speed drive and generator
How is normal power restored after an ADG deployment if a generator returns?
By stowing the ADG handle and pressing the PWR TXFR OVERRIDE button
Can hydraulic pump 3B be deselected after an ADG deployment?
No, it is hardwired to the ADG bus for continuous operation
What does the amber light on IDG switches mean?
HOT LOP