CRJ-200 Systems and Limitations Flashcards
(395 cards)
What is the APU exhaust danger area?
15 ft
What is the hazard area in front of the engine at IDLE thrust?
12 ft
What is the hazard area in front of the engine at FULL thrust?
25 ft (Leading edge of the wings)
What is the maximum weight and number of passengers allowed on the passenger door stairs?
4 passengers or 1000 lbs
Which areas of the CRJ-200 are pressurized?
The flight deck, passenger cabin, cargo area and avionics bay are all pressurized. The aft equipment bay and the forward nose compartment are NOT.
What is the difference between the APU starting on the ground vs in the air?
In the air you need to press the APU PWR/FUEL and START/STOP buttons quickly, one after the other.
What is the minimum voltage required to start the APU and where could you check this?
22 volts. You can check this on the DC Electric synoptic page.
How many batteries are required to start the APU?
Both the MAIN battery and the APU battery are required for APU start.
How could you start the APU if the MAIN or APU batteries were at less than 22 volts?
External AC or DC power.
What occurs when the APU PWR/FUEL Switchlight is selected?
- The APU performs a Bite Test
- RPM and EGT gauges appear on status page
- APU intake door opens
- APU shut-off valve opens
- APU/XFLOW fuel pump turns on
What happens when you press the START/STOP switchlight during an APU start?
- Energizes the starter motor
- Fuel and ignition introduced at 4% RPM
- ECU de-energizes the starter motor at 50% RPM
- Ignition is de-energized at 99% + 4 seconds
What happens when you select the START/STOP switchlight during an APU shut down?
- Fuel shut-off valve closes
- APU shuts down
- Intake door closes
- ECU initiates a 60 second Bite Test
How long should you wait after shutting down the APU before attempting a re-start? How would you know the waiting period is over?
You should wait 2 minutes. You know 2 minutes has passed when the EGT and RPM gauges disappear.
From where does the APU get its fuel?
From the left and right wing tanks
Which pump provides pressurized fuel to the APU?
The APU/XFLOW fuel pump
If the APU/XFLOW fuel pump failed, how would the APU be able to continue running?
APU Negative Gravity Release Valve.
It delivers fuel from the right main fuel manifold any time the pressure is greater than that of the pressure in the APU fuel manifold.
What does the green AVAIL light indicate on the APU START/STOP push button?
Bleed air is available for loading
After starting the APU, how long should you wait before applying bleed air loading?
To prolong APU life, you should wait 2 minutes prior to using the bleed air.
From where does the APU receive intake air, and where is it located?
From the APU Intake Door.
It’s located on top of the fuselage, forward of the tail.
How is the APU’s titanium compartment cooled?
It is ventilated by discharged air from the oil cooler which is then discharged into the atmosphere through an exhaust eductor.
Name four times the APU will shut down in the air?
1.) Fire Detected
2.) Overspeed (RPM >107%)
3.) ECU Failure
4.) DC Power loss
Which APU indication is ALWAYS shown on the Status page?
Intake door position
Which factors influence APU door position in flight?
- True Airspeed
- Altitude
- Weight on Wheels
What is the difference between how the APU fire detection system reacts in the AIR vs on the GROUND?
In the AIR the APU will shut down automatically, but the crew must manually deploy the fire bottle.
On the GROUND the APU will shut down and blow the fire bottle automatically after 5 seconds.