Oxygen

Question 2

What does a cyan oxygen indication on the EICAS mean?

Answer 2

GREEN - 3 man crew

CYAN - 2 man crew

Question 3

What does an amber oxygen indication mean?

Answer 3

Operating int he cautionary range. NO GO

Question 4

What are the crew oxygen masks modes?

Answer 4

• EMERG
• 100%
• NORM

Normal mode for dispatch is 100%

Question 5

Explain NORM mode on cabin chewy oxygen mask

Answer 5

With the mask regulator set to “NORM”, the oxygen supply is diluted (mixed with ambient air). At lower cabin altitudes, ambient air is mixed with the oxygen supply. As the cabin altitude increases, the amount of ambient air mixture is reduced until at a preset point where the user inhales 100% oxygen. In event of a cabin decompression when the ambient pressure is below the set point, the mask automatically provides non-diluted oxygen (100%) to the crew.

Question 6

Explain the 100% mode on oxygen crew mask

Answer 6

With the mask regulator set to “100%”, the mask provides pure oxygen to the pilot upon demand. This 100% supply is provided regardless of cabin altitude. Use of the “100%” mode ensures the pilot is protected from inhaling smoke or toxic fumes. Ensure the mask is selected to 100% prior to dispatch.

Question 7

Explain the EMERG mode on oxygen crew mask

Answer 7

With the mask regulator set to “EMER”, pure oxygen is delivered (forced) under positive pressure. This positive pressure forms a seal and purges smoke and toxic fumes that can get into the mask. Use of this mode can make it difficult to communicate until the pilot adjusts to the sensation of forced oxygen flow to the lungs.

Question 8

How do you reset the oxygen mask?

Answer 8

Oxygen flow can be terminated by closing the stowage box doors and pressing the TEST/RESET button.

Question 9

How is the passenger oxygen supply?

Answer 9

Individual chemical oxygen generators supply the passenger oxygen during an emergency descent in the event of cabin depressurization. Each generator can supply oxygen for about 12 minutes ( standard), 14 minutes(optional), or 22 minutes (optional)

Question 10

When do the masks automatically fall?

Answer 10

When cabin ALT reaches 14,500 ft. However due to system tolerances, it may occur between 14,000ft and 14,750ft.

Question 11

Up to what altitude is the PBE operational?

Answer 11

25,000 ft and up to 15 minutes