ATPL: The atmosphere contains the following gases:
Domanda 338, Human Performance and Limitations - ATPL - Airline Transport Pilot license
| 78% helium, 21% oxygen, 1% carbon monoxide, rest: rare gases |
| 78% nitrogen, 21% oxygen, 1% carbon monoxide, rest: rare gases |
| 78% helium, 21% oxygen, 0,03% carbon dioxide, rest: rare gases |
| 78% nitrogen, 21% oxygen, 0,03% carbon dioxide, rest: rare gases |
