OXYGEN REQUIREMENTS

Question 1

When is “First Aid Oxygen” required to be onboard for the passengers?

Answer 1

When a flight is planned above 35000 ft

Question 2

What are the oxygen requirements on board for a flight above FL 250?

Answer 2

Pax:
* 100% of Pax above 15’000 ft, minimum 10 min
* 30% of Pax between 12’000 - 15’000 ft
* 10% of Pax between 10’000 - 12’000 ft

Flight Crew:
For the duration the the cabin exceeds 10’000 ft, minimum 2h

Cabin Crew:
For the duration the cabin exceeds 10’000 ft + an individual portable supply for 15 min

Question 3

When shall Flight Crew use oxygen masks?

Answer 3

At all times cabin altitude exceeds 10’000 ft

Question 4

What is the time of useful consciousness at:
- 35000 ft
- 30000 ft
- 25000 ft?

Answer 4

35000 ft = 20 sec
30000 ft = 35 sec
25000 ft = 2 min

Question 5

What is considered a “safe cabin altitude” for passengers?

Answer 5

Below 14’000 ft oxygen masks are not required to be worn

Question 6

What are the 3 modes on the Flight Crew oxygen masks and what are the differences?

Answer 6

1. Normal
2. 100%
3. Emergency

Question 7

When would you use the “Emergency” mode on an oxygen mask?

Answer 7

Emergency mode is used to provide 100-percent oxygen under constant pressure. This limits inhalation of any cockpit smoke or noxious fumes.

Question 8

What is the difference between the “Normal” and “100%” modes on an oxygen mask?

Answer 8

“100%” puts in 100% oxygen
“Normal” mode preserves oxygen supply by regulating the percentage (flow) of oxygen depending on cabin altitude. Typically, above about 32,000 feet the two modes are identical, as there is no dilution—but at lower altitudes, oxygen savings may be considerable.

Question 9

What rules apply when replenishing oxygen?

Answer 9

• No pax onboard
• No traffic within 15m
  from the filling
  connection
• Refueling
• Radio communication

Question 10

How are the flight crew oxygen masks tested?

Answer 10

1. Press and hold the
   Reset/Test pb in the
   direction of the arrow
   *Check blinker goes
   out
2. Hold Reset/Test pb,
   and press the
   emergency pressure
   selector.
   *Check blinker stays
   yellow
3. Check set to 100%
4. Press emergency
   pressure selector
   again, and check that
   the blinker does not
   turn on

Question 11

When will the green oxygen overpressure disc rupture?

Answer 11

2500 - 2775 psi