CA.VIII.A.R1FAA-S-ACS-7B · Nov 2023Risk management
High altitude flight.
High altitude flight.
Bottom line
Hypoxia is a state of oxygen deficiency in the body sufficient to impair functions of the brain and other organs. The effects of hypoxia are usually quite difficult to recognize, especially when they occur gradually. 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
- AIM 8-1-2 (Effects of Altitude) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- 14 CFR 91.211 (Supplemental oxygen.) — eCFR current as of 2026-03-05
- AC 61-107, para. 2-7 — AC No: 61-107B
- AIM 8-1-3 (Hyperventilation in Flight) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- AC 61-107, para. 2-9 — AC No: 61-107B
- PHAK ch. 7 (p. 7-37) — FAA-H-8083-25C (2023)
- PHAK ch. 17 (p. 17-24) — FAA-H-8083-25C (2023)
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