So one thing that always struck me as kind of odd was when you depart a class D tower (VFR) and you get your departure instructions, that's kind of ... it. You just go on your merry way and switch off frequency whenever you want to.

Do people just stay on the tower frequency listening until they're outside of the airspace? Or do you give the tower a courtesy call (N123 leaving the class D) when you get to the boundary, and then switch off?

Or, is it legal to switch immediately to another frequency as soon as the tower says 'left turnout approved, resume own navigation'? It always seemed a bit of a hole to me. But, are controllers bothered by a extra "check out" on leaving the class D?

  • $\begingroup$ I have added the faa-regulations tag. I assume you are not interested in an ICAO/EASA based answer? $\endgroup$ Commented Apr 16, 2015 at 10:32

2 Answers 2


The AIM covers this from an operations / legal standpoint:

3-2-5. Class D Airspace

4. Departures from:

(a) A primary or satellite airport with an operating control tower. Two‐way radio communications must be established and maintained with the control tower, and thereafter as instructed by ATC while operating in the Class D airspace. [emphasis mine]

While operating in Class D airspace, you must maintain two-way radio contact with the tower – monitor the frequency and be prepared to respond.

You may leave the frequency once you are either clear of the airspace, or receive instructions to that end from ATC ("N1234, frequency change approved").

Whether or not controllers are bothered by you letting them know that you've left, I can't say, but it would probably qualify as frequency congestion. If they want to get in touch with you, they'll try ("N1234, are you still with me?"), but once you're outside the Class D airspace they're generally only providing advisory information.

  • 1
    $\begingroup$ Good answer; just wanted to add that the actual reg covering this is 91.129, paragraph c. The AIM in and of itself is not a regulatory document, but it does serve as the official guide to a good many items of interest, including how to abide by the regulations laid out in 14 CFR as exemplified by the section quoted above. $\endgroup$
    – habu
    Commented Apr 15, 2015 at 19:42

You are responsible for staying on frequency as long as you are in the class D space, UNLESS you are granted an early frequency change.

Once you leave Class D, you are free to change frequencies without notice.
If its a busy area, many controllers will still give you traffic advisories as long as you're nearby, and its reasonable to stay on frequency until you're considerably outside their space.

If its a very quiet area, it might be friendly to tell the controller to have a nice day as you're leaving.

One reason you may want an early frequency change is if you want to talk to another authority ASAP.

For example, Boeing Field (KBFI) and Renton Municiple (KRNT) are very close together, with adjoining Class-D spaces. Its common for practice flights to go between them. (Example map).

The conversation may go like:

You: "Boeing Tower; N513WF: Holding short, Rwy 13L, ready to go; Request early Frequency Change to Renton"

Tower: "3WF: Cleared for Takeoff, Rwy 13L. Frequency Change approved above 400 feet. No turns until instructed."

You get to 400+ feet, then call up Renton:

You: "Renton Tower: N513WF, out of Boeing's 13L, request touch-n-gos"

Renton: "3WF: Enter Right-traffic, following a Warrior, you're #2"

Congrats: You're talking to Renton, while still inside Boeing's Delta-space.

  • 6
    $\begingroup$ If its a busy area, many controllers will still give you traffic advisories as long as you're nearby, and its reasonable to stay on frequency until you're considerably outside their space. <-- That's an important point. Generally I think it's a good idea to continue monitoring tower (or CTAF/UNICOM) until you're well outside the range where inbound aircraft may be calling up, as an aid to situational awareness. (Or until you're talking to some other ATC facility, which generally serves the same purpose.) $\endgroup$
    – voretaq7
    Commented Jan 3, 2014 at 21:27

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