Oxygen System
Oxygen Systems in aircraft provide supplemental breathing oxygen when cabin altitude exceeds safe levels, either during normal high-altitude operations or during cabin depressurization emergencies.
- Flight crew oxygen: Gaseous oxygen in high-pressure cylinders, delivered via diluter-demand or pressure-demand masks — available for entire flight duration
- Passenger chemical generators: Sodium chlorate 'candles' that generate oxygen when activated — provide 12–22 minutes of oxygen (enough for emergency descent)
- Portable oxygen bottles: For cabin crew use, first aid, and walk-around
- Activation: Passenger masks deploy automatically when cabin altitude exceeds 14,000 ft
- Crew must don oxygen masks within seconds at cabin altitudes above 10,000 ft
- Above FL410, one crew member must wear an oxygen mask at all times