The EASA recommendation for supplemental-oxygen use on non-pressurised flights under Part-NCO:
NCO.OP.190 — "Use of supplemental oxygen"
| Cabin altitude | Requirement / recommendation |
|---|---|
| Up to 10 000 ft | No supplemental oxygen required |
| 10 000–13 000 ft for more than 30 minutes | Crew supplemental oxygen recommended |
| Above 13 000 ft at all times | Crew supplemental oxygen recommended |
| Above 14 000 ft | Passengers should also receive oxygen (national / operator-specific) |
Important: For NCO operations these are currently recommendations (not strict limits as for commercial operations). Always check the current rule text (Easy Access Rules for Part-NCO, Nov 2025).
Comparison with FAA rules (useful for international flight)
FAR 91.211 is stricter than EASA-NCO:
| Altitude | FAR 91.211 rule |
|---|---|
| 12 500–14 000 ft cabin altitude | Crew must use O₂ after 30 min |
| > 14 000 ft | Crew continuously on O₂ |
| > 15 000 ft | O₂ available for every occupant |
Equipment
- Continuous-flow system — simple, common in GA. O₂ mask + flow meter.
- On-demand / diluter-demand — more sophisticated, common in business aviation. Delivers O₂ only on inhalation.
- Cockpit pulse oximeter as saturation monitor recommended.
Safe storage
- No oil, grease, or solvent in the oxygen system (explosion / fire risk under pressure).
- Regular pressure tests of bottles per applicable rules.
- No smoking with oxygen flowing.