AI.II.I.K2FAA-S-ACS-25 · Nov 2023Knowledge
Altitude selection accounting for terrain and obstacles, glide distance of airplane, vi...
Altitude selection accounting for terrain and obstacles, glide distance of airplane, visual flight rules (VFR) cruising altitudes, and effect of wind.
Bottom line
To avoid terrain and obstacles, especially at night or in low visibility, determine safe altitudes in advance by using the altitudes shown on VFR and IFR charts during preflight planning.
Key numbers
| Number | What it means |
|---|---|
| more than 3,000 feet AGL, level cruising VFR flight | Rule floor |
| holding pattern of 2 minutes or less, or turning | Holding exception |
| altitudes may approach airplane performance limits | High terrain |
FAA references
- AIH ch. 1 (p. 1-6) — FAA-H-8083-9B
- AFH ch. 3 (p. 3-23) — FAA-H-8083-3C
- 14 CFR 91.159 (VFR cruising altitude or flight level.) — eCFR current as of 2026-03-05
- RMH ch. 3 (p. 3-15) — FAA-H-8083-2A
- AFH ch. 18 (p. 18-4) — FAA-H-8083-3C
- AIM 3-1-5 (VFR Cruising Altitudes and Flight Levels) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- RMH ch. 3 (p. 3-6) — FAA-H-8083-2A
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