EJET SYSTEMS QUESTIONS (AQP - PRE-CLASS) Flashcards
On the CVR/DVR how much time does it have for recording?
120 Minutes of Datalink
120 Minutes of communication (among ourselves)
25 flight hours of the aircraft
What does the IDG light mean?
It means “HOTLOP” High Oil Temperature, or Low Oil Pressure for the IDG. Letting us know which IDG should be disconnected
What are the ratings of the IDG?
115 Volt, 40 KVA, 400 HZ, 3 phase
Achieved by a constant speed drive going at 12,000 RPMs
What does the IDG power?
IDG 1 powers the AC BUS 1
IDG 2 powers the AC BUS 2
What is the bus priority for powering the airplane?
“ONSIDE, INSIDE, OUTSIDE, OFFSIDE”
- Onside IDG
- APU generator
- GPU generator
- Opposite IDG
Can the IDG power both buses?
Yes, if we lose an engine the remaining IDG will power both buses (thru system logic) until the APU comes online, which will power the failed side.
What does the AVAIL light mean on the GPU button?
Proper Phase, Voltage, Frequency (to connect the GPU to the AC BUS TIE)
What will happen with the AC BUS TIE 1 OPEN knob selection?
Isolates the AC BUS 1 from AC BUS 2 (by opening the AC BUS 1 tie contactor)
What will happen with the AC BUS 2 TIE OPEN switch?
Isolates AC BUS 2 from AC BUS 1 (by opening the AC BUS 2 TIE CONTACTOR)
What is BATT 2 used for?
Only for APU start. it comes off the electrical grid to start the APU thru the APU START BUS
What are the ratings of the BATTERIES (BATT 1 and 2)?
22.8 Volts, 27 amps
When will electrical and pneumatic power be available with APU as the source?
95% plus 3 seconds
What is the APU rated at?
115 Volts, 40 KVA, 400 hz
When will the APU automatically shut down in-flight vs. on ground?
“UFO SHELF”
In-air/ground:
- APU underspeed
- FADEC critical Fault
- APU Overspeed
On-Ground:
S - Sensor Fail H - High Oil Temperature E - EGT over temperature L - Low Oil Pressure F - APU Fire
If Batteries are the only power on the aircraft how long do we have?
10 Minutes of power for aircraft essential systems (if RAT failed)
When does the BATT 1(2) OVERTEMP come on?
When batteries reach a temperature above 70 degrees C for at least 2 seconds.
What is the minimum battery temp for starting the APU?
-20 degrees C
What equipment/components are on the HOT BATT BUS 1?
- Fuel
- Hydraulics
- Pneumatics
- 1A/2A
- Fire Handle (extinguishing)
- Engine Servicing
- Cabin service lights
What equipment/components are on the HOT BATT BUS 2?
- Fuel
- Hydraulics
- Pneumatics
- 1B/2B
- Fire Handle (extinguishing)
- Engine servicing
- Fueling panel (refuel/refuel)
- Potable water servicing
How many TRUs do we have?
3 TRUs (TRU 1, TRU 2, TRU ESS)
What is the purpose of the TRU?
To convert 115 Volts of AC to 28 Volts of DC
What are the TRUs rated at?
300 amps
What does TRU 1 power?
DC BUS 1 DC ESS Bus 1 DC Ground service bus HOT BATT BUS 1 Battery 1 Charging
What does TRU 2 power?
- DC BUS 2
- HOT BATT BUS 2
- DC ESS 2 bus
- Battery 2 charging
What does TRU ESS power?
DC ESS bus 3
When would we need to use the DC GPU?
When BATT 2 is no longer available or when battery temperature is below -20 degrees C
How much power does the DC GPU provide?
24-29 volts of DC power
What is the purpose of the Inverter?
To convert 28 volts of DC power to 115 volts of AC power, when there is no other AC source of power.
What is the rating of the inverter?
Rated at 300 Amps, 250 volts
What does the inverter power?
AC standby bus (which has igniters 1 and 2 on the bus)
When does the RAT deploy?
Automatically: when both AC bus 1 and bus 2 have failed, (NOT ENGINE FAILURE, just generators).
Manually: by pulling the handle
What is the RAT rated at, what kind of power does it produce?
15 KVA, 115 Volts of AC, 400 HZ, 3 phase
What limitations are associated with the RAT?
- 8 second limitation to get the RAT online, (adjust blade angles to high speed flight)
- 130 knots, the RAT will load shed to get the power down (40 KVA down limit)
- galley, window heating right side - No more than flaps 3 Landing, the RAT could quit earlier due to speed to spin the RAT
How many ICCs (integrated Control centers) do we have?
4, LICC, RICC, EICC, AICC
- Left ICC
- Right ICC
- Emergency ICC
- Auxiliary ICC
What is the purpose of the ICC (integrated control center)?
To protect the power coming onboard the aircraft and distribution
How many SPDAs (secondary power distributing assembly) do we have?
2
What is the purpose of the SPDA (secondary power distributing assembly)?
It provides power distribution from the ICCs to specific aircraft systems
What does the RAT power?
“Hydraulic Pump 3A, slats/flaps, igniters/exciters”
AC ESS BUS
- this powers the AC STANDBY BUS, IGNITERS/EXCITERS is on that
- SF-ACE 1 FLAP CH 1 AC FEED
- SF-ACE 2 SLAT CH 2 AC FEED
- AC FUEL PUMP 2A
- TRU ESS BUS
What is the Generator Control Unit, and what does it do?
Located in the ICCs it provides protection of the primary AC/DC electrical system.
(Overvoltage, Undercurrent)
When would we get a fuel low level caution?
1,320 lbs (in respective tank)
When would we get a fuel low level warning?
660 lbs (in respective tank) Can come on at 3,970 lbs (if scavenge pumps are plugged)
Where is the fuel temperature taken from?
Left wing tank, green above -37 degrees C
What is the high pressure relief valve used for in the fuel system?
To relieve pressure from the fuel tank from being overpressurized
How many fuel pumps does the aircraft have?
11 pumps
- Ejector fuel pumps (x 2, each wing)
- AC electric fuel pumps (x 2, each wing)
- Scavenge Ejectors (x 3 per wing)
- DC electric fuel pump (right wing only)
When does the FUEL IMBALANCE EICAS message appear? Disappear?
Comes on at 800 lbs imbalance, disappears when the imbalance is reduced to 100 lbs
What tank does the APU get its fuel from?
normally, right collector tank. BUT XFEED operations allows the APU to get it’s fuel from either tank
Explain XFEED operations with LOW 1 tank?
Fuel quantity is lower in tank 1 then tank 2, so turn the XFEED switch to low 1
- AC FUEL pump 2 comes on to feed fuel to tank 1
Explain APU FUEL XFEED?
To feed APU go LOW 2 and left side fuel AC PUMP 1 will feed fuel to the APU or left ejector pump to the APU if it’s available
What pump runs fuel to the APU?
DC fuel pump, installed in the right wing collector tank supplies fuel to the APU, normally.
What will happen if the APU is inoperative and no AC power is available for fuel purposes?
DC fuel pump will be used for initial fuel supply
What happens when you pull the red FIRE HANDLE?
Shuts down the engine and closes
- engine bleed valve
- Hydraulic and Fuel SOV
Explain the AFT CARGO SMOKE button illumination?
2 independent smoke detector channels are installed in AFT cargo compartment
- both must detect a smoke condition to send an alarm
Explain the FWD CARGO SMOKE button illumination? How does it illuminate? What happens?
3 smoke detectors are installed in the FWD cargo compartment
- 1 smoke detector detects smoke it goes into ALARM mode, shutting down the air circulation fan, and closing the ventilation valve
- The other smoke detectors are in ALARM mode for 45 seconds
- Air circulation fan is shut down for 60 seconds
- the system is doing a self test (BIT)
- If absence of an alarm it will treat it as a fault
- if another detector goes off within the 45 seconds a “CRG FWD SMOKE” is annunciated
What happens with inflight and the CARGO SMOKE button illuminates and you press it?
1 Push
First push: high rate bottle fires and low rate bottle arms then fires after 60 seconds (manually if you hit it again)
What happens while inflight and there is no indication of the CARGO SMOKE button illuminated and you hit it?
First push: High rate bottle arms
Second push: high rate bottle fires and low rate bottle arms, then fires after 60 seconds
Third push: low rate bottle fires immediately rather than 60 seconds
What happens while on ground and the CARGO SMOKE button illuminates and you hit it?
First push: high rate bottle fires, low rate bottle arms
Second push: low rate bottle fires
What happens while on the ground and the CARGO SMOKE button is not illuminated and you hit it?
First push: high rate bottle arms
Second push: high rate bottle fires, low rate bottle arms
Third push: low rate bottle fires
How does the APU detect fire?
The APU has 2 pneumatic fire detectors to detect a fire or overheat condition
- Located in the APU compartment
The fire detectors are connected to the MAU 1 and MAU 3 thru the DC ESS bus 1 and 2 which sends signals to the cockpit if both loops detect a fire OR (if one loop is inoperative the remaining loop)
What does the APU EMER STOP button red portion mean?
It illuminates red in the event of a APU FIRE has been detected
What happens when you press in the APU FIRE EMER button?
The APU will shut down immediately (by closing the APU Fuel SOV), without a cool down period
The white striped portion will illuminate signaling the APU EMER Button has been pressed in
What does the white stripe illumination on the APU EMER Button mean?
That the APU EMER button has been pushed in
When does the APU FIRE button illuminate?
When the APU detects a fire
What happens when you press in the APU FIRE EXTINGUISHER button?
Discharges the APU fire extinguisher
Shuts down the APU via the APU FADEC
Closes the APU Fuel SOV
EICAS displays an APU FIREX BTL DISCH advisory message
What happens if there is an APU fire on the GROUND?
APU will shutdown automatically in 10 seconds
- If there was no APU commanded off by the APU EMER STOP button
After 60 seconds APU EMER STOP button turns white and APU FIRE push button turns red
What happens during a FIRE TEST when you push the button?
“6,2,7” - 6 lights on overhead panel illuminate ENG 1(2) FIRE HANDLE CARGO FWD/AFT Smoke extinguisher buttons APU FIRE extinguisher button APU EMER STOP red portion (top half red) - 2 glareshield lights illuminate Warning LEFT/RIGHT - 2 Aural warnings sound (bells) - 7 EICAS Messages ENG 1(2) FIRE APU FIRE CRG FWD/AFT SMOKE ENG 1(2) ITT - FIRE displayed
Also:
- FWD cargo compartment fan stops running
- The ventilation outflow valve closes if bleed air is supplied by the engines or APU
Why is it important to NOT FIRE TEST with the APU running?
- To test the FIRE DETECTION system on the Batteries (DC source) not AC source with AC power supplying the aircraft
- In case of cargo loading the ventilation outflow valve (Cargo compartment SOV) will not close, in case of bags being loaded and live animals
What is the timer position on the WINDSHIELD WIPERS?
Allows the wipers to be on a timer, 8 seconds for 2 sweeps
Are there any limitations pertaining to the WINDSHIELD WIPERS?
Cannot be used on dry winshield, can get stuck and then bottle of water needs to be added to get them to move. To reset the wipers move the switch to OFF
Aircraft on ground, faulty smoke detector is realized, What happens?
“CRG FIRE PROT FAULT” appears on EICAS
On ground, if all the smoke detectors fail what happens?
“CRG FWD FIRE SYS FAIL” appears on EICAS
How does the LAVATORY FIRE PROTECTION/EXTINGUISHING work?
Smoke detector in Lavatory detects smoke then:
- Alarm will sound - Light will illuminate on detector rainbow stripe lights near FA station (visual cue for FIRE) - “LAV SMOKE” warning EICAS will be illuminated on cockpit screen
Lavatory Fire extinguisher
- has tips that will melt at 78 degrees C, releasing the fighting agent into the waste disposal