CA.VIII.A.R2FAA-S-ACS-7B · Nov 2023Risk management
Use of supplemental oxygen.
Use of supplemental oxygen.
Bottom line
Altitude hypoxia poses the greatest potential physiological hazard to a flightcrew member when at altitude. As altitude increases above 10,000 feet, the symptoms of hypoxia increase in severity, and the time of useful consciousness rapidly decreases. For optimum protection, pilots are encouraged to use supplemental oxygen above 10,000 feet during the day, and above 5,000 feet at night.
FAA references
- AC 61-107, para. 2-7 — AC No: 61-107B
- PHAK ch. 17 (p. 17-4) — FAA-H-8083-25C (2023)
- AC 61-107, para. 2-7, 2-9 — AC No: 61-107B
- 14 CFR 91.211 (Supplemental oxygen.) — eCFR current as of 2026-03-05
- PHAK ch. 7 (p. 7-37) — FAA-H-8083-25C (2023)
- AIM 8-1-2 (Effects of Altitude) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
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