OXYGEN

Question 1

How can the oxygen quantity be determined?

Answer 1

On the oxygen pressure display on the MFD status display

Question 2

How many oxygen cylinders are used for the flight deck?

Answer 2

1

Question 3

When is the oxygen mask microphone enabled?

Answer 3

Automatically when the left stowage box opens

Question 4

How is the oxygen harness inflated?

Answer 4

By squeezing the red flaps

Question 5

What is the difference between the Normal and 100% positions on the mask?

Answer 5

• NORMAL. This gives the pilot diluted oxygen on demand. Percentage oxygen flow is regulated depending on altitude.
• 100%. This gives un-diluted oxygen to quickly remedy hypoxia. The mask should be stored in this mode. Above about 32’000 ft the NORMAL and 100% modes are identical, as there are no dilution, but setting it back to NORMAL at lower altitudes may save a considerable amount of oxygen.

Question 6

How is oxygen shut off to the mask after usage?

Answer 6

Press the “Press to test/reset switch”

Question 7

How is oxygen turned on if mask is out of the box and the stowage doors are closed?

Answer 7

Open the left stowage box door

Question 8

Is the pax oxygen gaseous or chemically supplied?

Answer 8

Gaseous

Question 9

When do the passenger masks deploy automatically and what things happens automatically at the same time?

Answer 9

At 13’500 ft cabin altitude and above 80 kts airspeed or plane is in the air :

• Passenger masks deploy automatically
• An automatic PA announcement plays at maximum volume
• Passenger compartment lights come on bright
• No smoking -and fasten seat belt signs comes on automatically

Question 10

When can the “CREW OXYGEN LOW” EICAS message be displayed?

Answer 10

“CREW OXYGEN LOW” alerts the flight crew of a low oxygen pressure condition. A bleed valve opens for 15 seconds when the first engine starts. If the shutoff valve is not open, oxygen does not pressurize the supply line and the EICAS message will come up.

Question 11

What is the normal PSI level of the crew oxygen bottles?

Answer 11

1850 PSI

Question 12

What is the PSI level that reaches the crew oxygen masks?

Answer 12

60-85 PSI via two pressure regulators

Question 13

At what pressure will the green oxygen pressure disc break?

Answer 13

The green disc on the left side of the fwd fuselage breaks if cylinder pressure goes over 2’500-2’750 psi.

Question 14

How do you enable the normal boom mike after oxygen use?

Answer 14

By closing the left door

Question 15

What is the purpose of the EMERGENCY mode on the crew oxygen masks?

Answer 15

• EMERGENCY. This mode provides 100% oxygen under pressure and is used to protect the pilot against smoke and harmful vapors. Can also remove condensation or fogging from the interior of the mask lens. Communication may be difficult in this mode.

Question 16

How do you test the oxygen masks microphone?

Answer 16

• Select the FLT interphone transmitter and set desired speaker volume
• Push and hold a MIC switch on either the ACP or the glareshield
• Push both the oxygen mask RESET/TEST switch and EMERGENCY/TEST selector. The sound of oxygen flowing should be heard through the speaker, verifying mic operation.

Question 17

Where are the oxygen cylinders for the passengers located, how many are there and what is the pressure?

Answer 17

The gas cylinders are located on the right side of the aft cargo compartment. There can be up to 25 cylinders depending on how the airlines want to configure it. A pressure regulator keeps the pressure to between 600 – 700 psi.

Question 18

How many portable oxygen bottles are onboard a B777-300ER?

Answer 18

The B777-300ER have 18 bottles on board. There is at least one at each door.