FAR 71.33 — Class A Airspace
FAR 71.33 defines Class A airspace from 18,000 feet MSL to FL600 over the U.S., including coastal waters and offshore areas. Key facts for pilot students.
In Plain English
FAR 71.33 defines where Class A airspace exists in the United States. Class A is the high-altitude IFR-only airspace where every flight must be on an IFR flight plan, in contact with ATC, and operating under instrument flight rules — regardless of weather.
The rule breaks Class A into three pieces:
- Contiguous 48 states: From 18,000 feet MSL up to and including FL600, including airspace over the ocean within 12 nautical miles of the coast. Alaska and Hawaii are excluded from this paragraph.
- Alaska: Same vertical limits (18,000 MSL to FL600) and 12 NM coastal extension, but excludes airspace less than 1,500 feet AGL and the Alaska Peninsula west of 160°00′00″ W.
- Offshore areas: Designated offshore airspace listed in FAA Order JO 7400.11K where the U.S. provides radar/navigation coverage in international airspace and applies domestic ATC procedures.
Why it matters: knowing the floor (18,000 MSL) and ceiling (FL600) tells you exactly when you must be IFR-rated, IFR-current, and on a clearance — a frequent checkride topic.
Regulation Text
14 CFR § 71.33§ 71.33 Class A airspace areas.
(a) That airspace of the United States, including that airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous States, from 18,000 feet MSL to and including FL600 excluding the states of Alaska and Hawaii.
(b) That airspace of the State of Alaska, including that airspace overlying the waters within 12 nautical miles of the coast, from 18,000 feet MSL to and including FL600 but not including the airspace less than 1,500 feet above the surface of the earth and the Alaska Peninsula west of longitude 160°00′00″ West.
(c) The airspace areas listed as offshore airspace areas in subpart A of FAA Order JO 7400.11K (incorporated by reference, see § 71.1) that are designated in international airspace within areas of domestic radio navigational signal or ATC radar coverage, and within which domestic ATC procedures are applied.
Effective Date Note:
By Docket FAA-2025-1763, Amdt. 71-57, 90 FR 41890, Aug. 28, 2025, § 71.33(c) was amended by removing “FAA Order JO 7400.11J” and adding in its place “FAA Order JO 7400.11K”, effective Sept. 15, 2025, through Sept. 15, 2026.
Editorial Note:
www.govinfo.gov.
Forcitations affecting § 71.33, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at
Federal Register
[Amdt. 71-14, 56 FR 65654, Dec. 17, 1991]
Oral Exam Questions a DPE Might Ask
Q1What are the vertical limits of Class A airspace in the contiguous United States?
Per FAR 71.33, Class A airspace extends from 18,000 feet MSL up to and including FL600 over the 48 contiguous states and the waters within 12 NM of the coast.
Q2How does Class A airspace differ over Alaska compared to the lower 48?
FAR 71.33(b) keeps the same 18,000 MSL to FL600 limits but excludes airspace less than 1,500 feet above the surface and the Alaska Peninsula west of longitude 160°00′00″ W.
Q3Does Class A airspace extend over the ocean, and if so how far?
Yes. FAR 71.33(a) and (b) extend Class A over waters within 12 nautical miles of the coast, and FAR 71.33(c) further designates certain offshore international airspace areas listed in FAA Order JO 7400.11K.
Studying for a checkride?
Related Sections in Part 71