If the official weather report for an airport for which Class D airspace is designated is showing IMC, is that controlling for a Class E surface extension (designated for that airport)?

For example, if I determine that I have 3 miles flight visibility and at least a 1000 ft. ceiling, can I fly through that Class E surface extension without receiving an SVFR clearance?


The ATC Orders 7-5-1(a)(4) say:

a. SVFR operations in weather conditions less than basic VFR minima are authorized:


  1. Only within the lateral boundaries of Class B, Class C, Class D, or Class E surface areas, below 10,000 feet MSL.
  2. Only when requested by the pilot.
  3. On the basis of weather conditions reported at the airport of intended landing/departure.

That means, ATC will issue SVFR clearances - or not - in the class E surface area according to the official airport weather.

The 'twist' here is that ATC can't issue an SVFR clearance anyway unless the pilot requests it. The AIM 4-4-6 simply says that an SVFR clearance is required "when the weather is less than that required for VFR flight". So as far as I can see, if you're in VMC in a class E surface area and you expect to remain in VMC then you aren't required to request SVFR, whatever the reported airport conditions are.

I'm actually not sure what your exact scenario is here (in contact with ATC or not, within 4NM or not, etc.) but in reality I suspect that ATC would say "N12345, the field is IFR, say intentions". If you tell them you're in VMC then they have no way to challenge that but they might hint strongly that you should request SVFR - "N12345, is there anything special you'd like to request?" - because it would clarify the situation for everyone and help keep you safe and legal.

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  • $\begingroup$ @pondlife- the question is whether or not 91.155 (c)- " Except as provided in §91.157, no person may operate an aircraft beneath the ceiling under VFR within the lateral boundaries of controlled airspace designated to the surface for an airport when the ceiling is less than 1,000 feet." applies to the Class E surface area, which has been established for (appended to) the Class D airspace, when the official wx report for that Class D's primary airport shows less than a 1000 ceiling. Operating in the Class D portion would require SVFR, but what about the Class E surface extension? $\endgroup$ – 757toga Mar 2 '18 at 0:13
  • $\begingroup$ @pondlife- in the early 1970's as a CFI I worked from a non-tower airport in the sfc extension of a control zone (predecessor of Class D). The extension was similarly established and appended to the control zone for the primary airport. When the official wx for the primary airport was less than 1000 ceiling and or 3 mi vis the entire control zone (including the extension) was declared IMC. I would be required to obtain a SVFR clearance to fly in and out of my non-towered airport. Principle is the same, but less procedural info on this is available since the change-over to airspace classes. $\endgroup$ – 757toga Mar 2 '18 at 0:28
  • $\begingroup$ @757toga According to the AIM 3-2-6: "Surface area arrival extensions become part of the surface area and are in effect during the same times as the surface area." I read that to mean that whatever applies in the surface area also applies to the extensions. This might be a case where a picture is worth a thousand words: is there a specific airport that you could use to illustrate the question? The mix of class D, class E, class E extensions and SVFR is making this question confusing, at least for me :-) $\endgroup$ – Pondlife Mar 4 '18 at 19:15
  • $\begingroup$ @Pondlife- My first comment above applies to my question. Suppose I am in Class G at 600 feet just below the overcast. I'm approaching a class E sfc extension appended to a class D area. The weather being reported at the class D airport is 700 overcast, 5 mi vis. Do I have to obtain a SVFR clearance to fly underneath the overcast thru the appended class E sfc extension (remaining clear of the class D space)? In other words, does the wx report from the primary airport for which the class D is established apply to the Class E extension? If it does, then I would have to get the SVFR clearance. $\endgroup$ – 757toga Mar 4 '18 at 19:31

No, the IMC designation is for the airport itself, not for the surrounding Class E airspace.

You are going to be flying at 500' AGL, assuming no buildings or people around, in a possibly active instrument approach corridor?

A 1000' ceiling = you must maintain yourself 500' below it in Class E airspace. The Class E extension is there for approach/departure protection for IFR operations.

If you must do it, call the tower please.

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    $\begingroup$ the question is whether or not the Class E surface extension is officially IMC since the Class D airspace, for which the Class E surface extension was created, is officially IMC. $\endgroup$ – 757toga Mar 1 '18 at 14:09
  • $\begingroup$ "officially IMC" is quite a label! "Officially", declared IMC is at an airport (and area) with on station weather reporting. The Class E extensions are not included in this area. That still puts you at 500' AGL to be legally clear of clouds as a VFR flight. $\endgroup$ – Mike Brass Mar 1 '18 at 18:51
  • $\begingroup$ Officially IMC means, in the context of my question, that the "official" weather report (nws, twr, awos, etc.) for the airport for which the Class D was established is showing vis below 3 miles and/or the ceiling below 1000 ft. Pretty straight forward. $\endgroup$ – 757toga Mar 1 '18 at 19:55
  • $\begingroup$ edited my answer, I was OK on explanation but I didn't answer your question before the edit. $\endgroup$ – Mike Brass Mar 1 '18 at 20:11

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