CA.I.E.K1FAA-S-ACS-7B · Nov 2023Knowledge
Airspace classes and associated requirements and limitations.
Airspace classes and associated requirements and limitations.
Bottom line
Uncontrolled airspace or Class G airspace is the portion of the airspace that has not been designated as Class A, B, C, D, or E. When overlapping airspace designations apply to the same airspace, the operating rules associated with the more restrictive airspace designation apply.
Key numbers
| Number | What it means |
|---|---|
| FL 600 | Class A top |
| 10,000 ft MSL | Class B top |
| 2,500 ft AGL | Class D top |
| 200 KIAS | Class C/D speed |
| 1,200 ft AGL | Class E base |
FAA references
- PHAK ch. 15 (pp. 15-2–15-3) — FAA-H-8083-25C (2023)
- AIM 3-1-3 (Hierarchy of Overlapping Airspace Designations) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- AIM 3-2-3 (Class B Airspace) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- 14 CFR 91.117 (Aircraft speed.) — eCFR current as of 2026-03-05
- AIM 3-1-1 (General) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- AIM 3-2-6 (Class E Airspace) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
- 14 CFR 91.135 (Operations in Class A airspace.) — eCFR current as of 2026-03-05
- AIM 3-2-2 (Class A Airspace) — AIM Basic 2/20/25 w/ Change 1 (8/7/25) & Change 2 (1/22/26)
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