Oxygen System Flashcards
How is crew oxygen flow indicated?
A bright yellow star when visible indicates that oxygen is flowing. (812 14-14-05 Pg 1)
On the oxygen pressure indicator, what is indicated when the pointer is coloured green, cyan or amber?
GREEN: Normal operating range (minimum for three crew members in the cockpit)
CYAN: advisory operating range (minimum for two crew members in the cockpit). (81214-14-05 Pg 4)
AMBER: Cautionary operating range (no dispatch)
How do passengers initiate oxygen flow and how long does it last?
Oxygen flows throughout all masks in the dispensing unit whenever any yellow mask hanging from the dispensing unit is pulled downward. (812 14-14-15 Pg 2)
Each Passenger Service Unit (PSU) contains either two or three masks that supply oxygen only for approximately 12 min (standard) -optional 14/22 min. (81214-14-15 Pg 1)
What does the green disk next to the crew oxygen refill point indicate?
Green disk indicates normal operating range. The green oxygen cylinder pressure relief disc blows out in the event of an overpressure. (812 14-14-05 Pg 7)
At what altitude do the passenger oxygen masks deploy automatically?
What action is required if they do not?
The masks are automatically deployed when the cabin altitude is between 14000 ft to 14750 ft. (812 14-14-15 Pg 2)
Selecting OVRD on Masks Deploy Selector Knob on the PASSENGER OXYGEN overhead panel in the flight deck deploys the passenger oxygen masks regardless of cabin altitude. (81214-14 05 Pg 3)
How do you shut off the oxygen flow to the crew masks after use?
Pressing the TEST /RESET button on the crew MASK STOWAGE BOX with the mask not stowed and the mask box door closed shuts off the oxygen flow, turns off mask’s microphone and returns the communication from the cockpit speakers to the headsets. (B12 14-14- 05 Pg 2)
If the discharge indicator disc is green what does this mean? What happens if this disc blows out?
GREEN: Normal operating range
Blows out if overpressure occurs
What is the oxygen cylinder pressurised up to?
1850psi
After loss of cabin pressure, sufficient oxygen is provided for all cockpit members to permit emergency descent from 41000ft to 10000ft in ____ min with mask regulator on ___ mode and continuing cruise at 10000ft for ___ min with mask regulator on ____ mode
41,000ft - 10,000ft - 22 mins in 100% mode
10,000ft for 98 mins in NORMAL mode
Difference between Normal, 100% and Emergency modes on the oxygen mask?
Normal: Mix of oxygen with cabin air
100%: Provides non diluted oxygen to the crew regardless of cabin altitude
Emergency: Non diluted oxygen with slight positive pressure
How long does the Protective Breathing Equipment (PBE) provide oxygen for?
15 minutes up to 25000ft
How many masks does each Passenger service unit contain? How long do they provide O2 for?
2-3 masks
12 min (standard)
14/22 min (optional)
What cabin altitude do the passenger masks deploy?
automatically between 14,000 - 14,750ft
What pressure are portable oxygen cylinders pressurised to? (Used to assist passengers in case of sudden cabin decompression or first aid)
1800 psi
When are passenger oxygen masks automatically deployed?
Between 14,000ft and 14,750ft
