The airspace over the United States is classified into various areas of "alphabet" airspace (A, B, C, D, E, G). This is known as "regulatory" or "rulemaking" airspace because the airspace classifications are established by rule and only after a public comment period. The regulations defining this areas of airspace are at 14 CFR 71, which "incorporates by reference" the airspace definitions published in FAA JO 7400.11 "Airspace Designations and Reporting Points".

There is also "non-regulatory" or "non-rulemaking" airspace, which is established without a comment period. TRSAs are one example of non-regulatory airspace. By definition, the definitions for these airspace areas are not published in the Federal Register or Code of Federal Regulations.

FAA JO 7400.2 "Procedures for Handling Airspace Matters" says that "Nonrulemaking actions must be published in the National Flight Data Digest (NFDD) on or before the applicable charting cutoff date." The NFDD is a stream of changes to many aspects of the NAS, without any clear historical organization.

Both regulatory (prohibited and restricted) and non-regulatory (military operations, alert, warning, and national security) special-use airspace areas are listed in FAA JO 7400.10 "Special Use Airspace". The actual definitions are published in the Federal Register (for regulatory SUA only) and the NFDD. TRSA airspace is not SUA and is not listed in the 7400.10.

Is there a published document which compiles the definitions of any or all TRSA airspace?


1 Answer 1


Since they are non-Part 71 airspace there would likely not be a regulatory-based list that compiles all of remaining TRSA's. As for the TRSA dimensions they would be defined as published on sectional charts (solid black lines).

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    $\begingroup$ I don't think the TRSA would be defined on the sectional, because the sectional is an inexact document. I would expect something like "That airspace within a fifteen-mile radius of MXF TACAN"—some textual description of the airspace. Obviously not a regulatory-based list but at least a definitive record somewhere. Perhaps they're in the individual facility SOPs... $\endgroup$
    – randomhead
    Sep 2, 2021 at 4:04
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    $\begingroup$ Maps are drawn from numerical data. The question is were are the numerical data provided to the map publisher? $\endgroup$
    – mins
    Sep 2, 2021 at 15:20
  • $\begingroup$ @randomhead Not sure I agree that a sectional chart is an "inexact" document. As far as I am aware every element on a sectional is defined precisely somewhere. The underlying map data is derived from various sources (local government, federal government, historical research, etc.). Since TRSA is non-part 71 airspace its dimensions do not go thru the rulemaking process. It may be that the TRSA dimensions are compiled by the controlling ATC Procedures Office, approved and then sent to the agency that produces the chart. The Procedures Office would then possibly have the TRSA dimension data. $\endgroup$
    – user22445
    Oct 2, 2021 at 20:11
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    $\begingroup$ @757 the sectional is "inexact" in that you cannot (necessarily) determine the exact geographical location of a feature or tower just by looking at it, nor the exact dimensions of the airspace depicted, etc. The underlying data is of course accurate to whatever degree deemed appropriate, but it's a one-way function—towers, roads, airspace boundaries, etc are by necessity much larger on the sectional than they are in real life (to aid visibility), which makes exact measurement difficult. $\endgroup$
    – randomhead
    Oct 2, 2021 at 21:26

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