FAR 71.51 — Class C Airspace
FAR 71.51 designates Class C airspace areas around primary airports, subject to Part 91 operating and equipment rules. What pilots need to know.
In Plain English
FAR 71.51 is the rule that formally establishes Class C airspace in the United States. Rather than spelling out the boundaries of every Class C area in the regulation itself, the FAA lists them in subpart C of FAA Order JO 7400.11K, which is incorporated by reference into Part 71.
Key points to understand:
- Each Class C area is built around at least one primary airport — typically a moderately busy airport with an operating control tower and approach radar.
- Inside Class C airspace, all aircraft operators must comply with the operating rules and equipment requirements found in Part 91 (such as two-way radio communications, a Mode C transponder, and ADS-B Out).
- The specific dimensions, shelves, and outer limits of each Class C area are published in the FAA Order, and depicted on VFR sectional and terminal charts.
Operationally, this section matters because it tells you where Class C exists and that you must follow Part 91 rules to enter — establishing two-way radio contact with ATC before crossing the boundary is the most common student pilot trip-up.
Regulation Text
14 CFR § 71.51§ 71.51 Class C airspace.
The Class C airspace areas listed in subpart C of FAA Order JO 7400.11K (incorporated by reference, see § 71.1) consist of specified airspace within which all aircraft operators are subject to operating rules and equipment requirements specified in part 91 of this chapter. Each Class C airspace area designated for an airport in subpart C of FAA Order JO 7400.11K. (incorporated by reference, see § 71.1) contains at least one primary airport around which the airspace is designated.
Effective Date Note:
By Docket FAA-2025-1763, Amdt. 71-57, 90 FR 41890, Aug. 28, 2025, § 71.51 was amended by removing “FAA Order JO 7400.11J” wherever it appears and adding in its place “FAA Order JO 7400.11K”, effective Sept. 15, 2025, through Sept. 15, 2026.
[Docket 29334, 73 FR 54495, Sept. 22, 2008, as amended by Amdt. 71-40, 73 FR 60940, Oct. 15, 2008; Amdt. 71-41, 74 FR 46490, Sept. 10, 2009; Amdt. 71-42, 75 FR 55269, Sept. 10, 2010; Amdt. 71-43, 76 FR 53329, Aug. 26, 2011; Amdt. 71-44, 77 FR 50908, Aug. 23, 2012; Amdt. 71-45, 78 FR 52848, Aug. 27, 2013; Amdt. 71-46, 79 FR 51888, Sept. 2, 2014; Amdt. 71-47, 80 FR 51937, Aug. 27, 2015; Amdt. 71-48, 81 FR 55372, Aug. 19, 2016; Amdt. 71-49, 82 FR 40068, Aug. 24, 2017; Amdt. 71-50, 83 FR 43757, Aug. 28, 2018; Amdt. 71-51, 84 FR 45652, Aug. 30, 2019; Amdt. 71-52, 85 FR 50780, Aug. 18, 2020; Amdt. 71-53, 86 FR 46963, Aug. 23, 2021; Docket FAA-2022-1022, Amdt. 71-54, 87 FR 54878, Sept. 8, 2022; Docket FAA-2023-1785, Amdt. 71-55, 88 FR 58072, Aug. 25, 2023; Docket FAA-2024-2061, Amdt. 71-56, 89 FR 68339, Aug. 26, 2024; Docket FAA-2025-1763, Amdt. 71-57, 90 FR 41890, Aug. 28, 2025]
Oral Exam Questions a DPE Might Ask
Q1Where can you find the legal description and dimensions of a specific Class C airspace area?
Per FAR 71.51, Class C airspace areas are listed in subpart C of FAA Order JO 7400.11K, which is incorporated by reference into Part 71.
Q2What rules apply to aircraft operating inside Class C airspace?
FAR 71.51 states that all aircraft operators in Class C airspace are subject to the operating rules and equipment requirements specified in Part 91 of the regulations.
Q3Is every Class C airspace area associated with an airport?
Yes. FAR 71.51 requires that each designated Class C airspace area contain at least one primary airport around which the airspace is built.
Studying for a checkride?
Related Sections in Part 71