The U.S. Aeronautical Information Manual, part 3−2−6, lists a variety of airspace areas which may be designated type E. From reading this section, I get the impression that "typical" class E airspace consists of regions near non-towered airports, plus everything from 14,500' MSL to 18,000' MSL.

The word on the street, however, is that this is not an accurate picture: In reality, class E airspace typically goes all the way from 1,200' AGL to 18,000' MSL, with dips down to 700' AGL around non-towered airports. I.e. apart from a thin layer of class G airspace near the ground, almost all airspace away from towered airports is class E. This is hard to notice on sectionals, since the only place it is mentioned is in the legend, where there is a footnote stating "Class E Airspace exists at 1,200' AGL unless otherwise designated as shown above." I gather this widespread sort of class E airspace falls under the provisions listed in AIM 3-2-6e4 and 3-2-6e5.

So I have two questions regarding this:

  1. Is there anywhere in the Coterminous U.S. where class G airspace extends up to 14,500' MSL? (Excluding the trivial case of mountainous terrain above 13,000' MSL; c.f. AIM 3-2-6d1b.)
  2. Since the existence of class E airspace from 1,200' MSL upwards is so ubiquitous, why is this not codified like the 14,500' rule is?
  • $\begingroup$ The second question is not answered there, we can edit this question to be not a duplicate $\endgroup$
    – Federico
    Sep 15, 2017 at 6:53
  • $\begingroup$ @Federico I tried making an edit as you suggest, but I couldn't make the second half stand alone as a question. Maybe the OP could clarify what doubts remain after reading the duplicate, and get the question reopened that way. $\endgroup$
    – Dan Hulme
    Sep 15, 2017 at 11:23
  • $\begingroup$ @DanHulme I'm afraid your edit got lost somehow $\endgroup$
    – Federico
    Sep 15, 2017 at 11:29
  • $\begingroup$ @Federico No, I threw away the edit because I couldn't make it work. $\endgroup$
    – Dan Hulme
    Sep 15, 2017 at 14:37

1 Answer 1


Historically there was much more uncontrolled airspace in CONUS. There is less but it exists. 14500 is the old continental control area, sometimes called the continental control shelf. It was designed with the highest natural obstruction in CONUS in mind.

In uncontrolled airspace IFR operations could be conducted without ATC involvement. I used to do this frequently.

The idea was that in the Continental Control Area, IFR ops were controlled.

For the second question, some Class G exists because there is inadequate service coverage and traffic density and the blanket classification to Class E is inappropriate.


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