AI.II.N.K3cFAA-S-ACS-25 · Nov 2023Knowledge
c. Precautions when using supplemental oxygen systems
Operational factors, including: c. Precautions when using supplemental oxygen systems
Bottom line
Pilots should be aware of the increased danger of fire when using oxygen. Pilot masks sometimes allow greater oxygen flow than passengers' masks, so it is important that pilots use the masks indicated for them. A drop in indicated pressure on a supplemental oxygen cylinder can be an indication that the oxygen supply has merely compacted (not necessarily a leak).
Key numbers
| Number | What it means |
|---|---|
| 1,800 to 2,200 psi | Cylinder psi |
| very careful attention above 25,000 ft MSL | Continuous flow |
| safe up to 40,000 ft MSL | Demand mask |
| safe above 40,000 ft MSL | Pressure demand |
FAA references
- AC 61-107, para. 2-9 — AC No: 61-107B
- AFH ch. 18 (p. 18-10) — FAA-H-8083-3C
- 14 CFR 91.211 (Supplemental oxygen.) — eCFR current as of 2026-03-05
- AC 61-107, para. 2-12 — AC No: 61-107B
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