ATPL: Dry air is a mixture of gases. Their volume percentage is about:
Domanda 442, Human Performance and Limitations - ATPL - Airline Transport Pilot license
| 18% oxygen, 80% nitrogen, 2% other gases |
| 21% oxygen,78% nitrogen, 1% other gases |
| 25% oxygen, 74% nitrogen, 1% other gases |
| 19% oxygen, 80% nitrogen, 1% other gases |
