Systems Questions (Oral and Test) Flashcards
Is there a speed limit for ADG deployment?
Yes, Vmo (335 Kts)/Mmo (0.85 Mach)
What is on the accessory gearbox?
- fuel pump (engine driven high pressure)
- integrated drive generators
- starter (air turbine)
- hydraulic pumps (engine driven) - EDP’s
- Oil Pump
- FADEC Alternator (+)
When does APR automatically arm?
When N1 RPM of both engines are within 8% of takeoff power, (normal or reduced)
What type of takeoff thrust setting is automatically calculated by FADEC?
Normal Takeoff thrust
What conditions are you looking for to move the thrust lever to idle position after engine start?
- N2 greater than 20%
AND
- ITT is 120 degrees or less
What doors are NOT on the Synoptics page?
- AFT equipment bay
- Crew Escape Hatch
How much core air thrust is produced by the CF34-8C5 (CRJ 900) engine?
20%
How much bypass air thrust is produced by the CF34-8C5 (CRJ 900) engine?
80%
How much engine thrust is produced by APR?
14,750 lbs
When will FADEC automatically increase thrust to the operating engine?
When an engine fails and N1 mismatch of 15% or more is detected
When is continuous ignition required?
- Takeoffs/Landings on contaminated runways
- Flight through moderate or heavy rain
- Flight through moderate or greater turbulence
- Flight in vicinity of thunderstorms
When does the air turbine starter disengage on the starter system?
N2 reaches 50%, of the STOP Switch light is pressed
When do we want to introduce fuel on an engine start (moving the thrust lever to idle position)?
- N2 is 20% or greater AND ITT is less than 120 degrees C
If NOT followed (HOT START will occur and FADEC will not allow engine to start)
FADEC will automatically abort a start for…
- Hung Start
- Hot Start
- L(R) START ABORT (caution message will be displayed)
Where is the Oil Replenishment Tank located?
AFT Equipment Bay
Reference Slide #73 - Powerplant
What stage of compression is bleed air extracted from?
6th and 10th stage
What are the thrust lever Detents located?
- Climb
- TOGA
- Max Power
What hydraulic system powers the left thrust reverser? Right thrust reverser?
- Left thrust reverser powered by hydraulic system # 1
- Right thrust reverser powered by hydraulic system # 2
Where is the APU located?
Located in the aircraft tail one
What causes the APU to automatically shutdown on the ground?
High Oil Temperature, Loss of Oil Pressure (“HOTLOP”)
In flight, what happens when there is a loss of oil pressure or high oil temperature in the APU?
Caution Message will appear on EICAS display but APU will continue to operate
Where does the APU receive fuel from?
Left collector tank via the APU fuel pump
What voltage on the batteries are we looking for prior to starting the APU?
Minimum of 22 volts on main battery and APU battery
Why do we need a minimum voltage on the main battery and APU battery prior to starting the APU?
Main battery powers the ECU, APU battery provides power to crank the starter
When we press PWR/FUEL switch light, what are we looking for on the EICAS display?
Look for “DIGS”
- DOOR OPEN
- IN BITE status message
- GAUGES (RPM and EGT) are displayed
- SOV OPEN status message
When can we press the START/STOP Switch light on the APU?
APU IN BITE status message disappears
When we press the START/STOP switch light on the APU what are we checking for?
- START switch light illuminates
- APU START status message is displayed
- APU Starts
When does the APU START switch light extinguish?
When starter cutouts, occurs between 46-60% RPM
When does the APU START status message disappear?
When starter cutouts, occurs between 46-60% RPM
When does the APU AVAIL light illuminate?
99% plus 2 seconds
What does the APU AVAIL light mean?
The APU is available for electrical loading
What is the Primary Purpose of the APU?
Electrical, to operate the gearbox mounted (40 KVA) generator
What is the Secondary purpose of the APU?
- Supply Bleed Air for Air Conditioning
- Supply Bleed Air for Pressurization
- Main Engine Starting
How long do you have to wait after the APU AVAIL light comes on for using the APU for bleed air?
Pneumatic loading will be available 99% plus 2 seconds
When does the APU automatically shut down?
On the ground after 5 seconds
What PSI does the APU LCV (load control valve) modulates to?
Regulates manifold pressure of 45 PSI
What is the purpose of the APU LCV (Load Control Valve)?
Protects the APU from over temperature condition
Why is gravity refueling fuel limits less than the pressure refueling limits?
Because of dihedral of the wing
Why is the NACA scoop designed in that shape?
To prevent ice buildup
How many motive flow ejector pumps are there? What are their names?
8 Ejectors
- 2 Transfer Ejectors
- 4 Scavenge Ejectors
- 2 Main Ejectors
Explain the use of the Transfer Ejectors…
Transfer ejectors are controlled by motive flow created by main ejectors
Transfer ejectors sends fuel from the center tank (when in use) to the Main Tank.
They automatically are activated when the main tank drops to 94% of fuel capacity (on the respective side).
The FSC (Fuel System Computer) will open the respective transfer valve, then close the respective transfer valve when the tank is full
This process continues until the center tank is empty
Explain the use of the scavenge ejectors…
Scavenge ejectors takes fuel from the main tanks to the collector tanks
2 per main tank (Synoptics page only shows one)
Gravity line connects the main tanks to the collector tanks to act as redundancy in case the scavenge ejectors fail
Explain the use of main ejectors…
Two main ejectors are operated by motive flow created by the the engine driven fuel pumps
Main ejectors takes fuel from the collector tank and delivers fuel to the engine
Reference Systems Manual Pg. 410, Ch. 11-8
Explain what will happen if the Engine driven fuel pump (EDP) stops working…
Nothing, the associated engine will quit
What is the purpose of the Fuel Boost pumps?
Acts as a back up to the main ejectors, when low pressure is detected
Moves fuel from the collector tanks to engines during engine start
How are the fuel boost pumps powered?
Electricity (electric boost pumps) DC powered
How will the Boost Pumps turn on?
- They need to be “ARMED” (pushed in)
- They need to sense a lower pressure from the main ejector on that side (by the Fuel System Computer)
- When one boost pump turns ON they BOTH TURN ON!
(If the left and right boost pump are pushed in “ARMED” and the left engine is running, but the right engine is NOT running, the right boost pump is sensing a LOW PRESSURE on that side, meaning it will TURN ON, this will make the LEFT fuel boost pump turn on as well… Being able to send fuel under low pressure to start the #2 (right) engine)
When will the INOP light on the Fuel Boost Pump turn on?
- Any time the fuel pump switch is not “ARMED” (pushed in)
- When the fuel boost pump has failed