Pressurization & Oxygen Flashcards
If cabin pressurization is lost, the aircraft will enter the emergency descent mode (EDM) if:
Autopilot ON
Red CABIN PRESS LOW CAS
Aircraft above 40,000 ft
If the airplane enters the emergency descent mode it will automatically level off at 15,000 ft. If this altitude is too low, what must be done to change the level-off altitude?
Disengage the autopilot and select the appropriate altitude in the flight guidance panel
On the ground, when does the FLIGHT / LANDING switch automatically switch to FLIGHT?
At taxi speeds above 9 kts, PLA > 15 degrees, or manually selected by crew
On the ground with the FLIGHT / LANDING switch selected to FLIGHT, how will the cabin pressurize?
Cabin will descend to 500’ below field elevation
How do you select between the 2 cabin pressure controller channels?
They automatically swap every flight (by opening & closing the main cabin door after landing), or by selecting the AUTO/MANUAL switch to MANUAL, then back to AUTO
What are the outflow valve motor power sources?
2 AC - ESS AC & R MAIN AC - Auto Mode
1 DC - L ESS DC - Manual Mode
When will the CABIN PRESS LOW CAS illuminate?
LFE < 7,500’ - 8,000 ft
LFE 7,500-9,500’ - 10,000 ft
LFE > 9,500’ - 14,500 ft
Manual Mode - 10,000 ft
What is the power source of the AUTO/SEMI pressure selection switch?
Channel 1 - ESS AC
Channel 2 - R MAIN AC
When does the dual channel pressurization controller switch channels?
By selecting then deselecting MANUAL on the pressurization controller, or by cycling the main door open and closed after landing
Is there a way to determine which channel of the pressurization controller is active?
By viewing the ECS / PRESS synoptic page - lower right corner, or SUMMARY page
Where does the pressurization system obtain altitude information?
Captain’s side selected ADM (Air Data Module)
Where does the pressurization system obtain its landing field elevation information?
The FMS or pressurization selector panel
When does the FLIGHT / LANDING switch change to landing?
During descent, change of altitude of more than 1000 ft, or selecting LANDING on the cabin pressure control panel
What happens to the FLIGHT / LANDING mode if the aircraft levels off after descent begins?
The pressurization system will continue to pressurize the aircraft to a normal pressure for that altitude. However, the FLIGHT / LANDING switch will still indicate LANDING (for 3 minutes >FL250, then switches back to FLIGHT)
What is the maximum cabin altitude in the AUTO operation?
8,000 ft
How do you control aircraft pressurization in the SEMI mode?
By pre-setting all the information in the CABIN PRESSURE SELECTOR PANEL located on the center console
How long does it take to open the PRV after landing in the SEMI / AUTO mode of operation?
1 minute after the outflow valve has fully opened
How is aircraft pressurization controlled in the MANUAL mode?
By manipulating the manual hold rate knob that controls the DC motor to open and close the TROV
If you are planning a flight from a low altitude airport to a high altitude airport (such as above 8000 MSL), how will the cabin pressurization system function?
The cabin pressurization (in AUTO) will climb the cabin to the correct cruise altitude differential until a descent is begun, at which time the cabin will climb to the landing field elevation.
What are the cabin differential pressure limits?
9.94 psi max differential
0.3 psi for taxi takeoff and landing
When will the pressure relief valve open?
If the TROV has failed, the PRV will begin to open at 9.74 PSID or -0.25PSID. However during normal operations, the PRV will open 1 minute after the TROV has fully opened on the ground after landing
How many power sources are there for the TROV?
3 Total: 2 AC, 1 DC
Channel 1 - ESS AC
Channel 2 - R MAIN AC
Manual - L ESS DC
At what cabin altitude will the passenger oxygen masks deploy, if in AUTO?
Either 13,000’ or 14,500’ depending on serial number an/or ASC installation
At what pressure and/or temperature will the oxygen blow-out disc discharge?
- Regulator oxygen pressure exceeding 90psi
- Oxygen cylinder pressure exceeding 2600psi
- Oxygen temperature exceeding 225F
If the small knob on the front of the oxygen mask is rotated to emergency, what will happen?
The recipient will be provided with oxygen under positive pressure
What will the normal position on the flight crew oxygen mask provide?
Diluted oxygen in a decreasing ratio up to approximately 35,000 feet
