It seems like I have a concept error here. I don't understand why "the VFR min is 1000/3" when I think I would need to check in which airspace I am to then check for its respective weather min corresponding to that airspace, so why bother saying 1000/3? (I am new in the community and trying to learn, apologize for entry level question)

Also, for example for class C airspace, the VFR weather mins are visibility 3sm and clouds 500 below, 1000 above, 2000 horizontal. "Above" means that clouds should be at least a distance away 1000' above the aircraft, is that what it means?

Finally, I read several websites but couldn't find if these weather minimums for each airspace are talking about only SCT and BKN ceilings or do they apply to OVC too? is it legal then to fly VFR and overcast?

  • $\begingroup$ When you read the "above/below" clearances, start them off with "I need to be...", for example in 2000/500 below/1000 above, you read that as "I need to be 2000 feet from (laterally), 500 feet below, and 1000 feet above clouds"... $\endgroup$
    – Ron Beyer
    Jul 20, 2021 at 2:03
  • $\begingroup$ got it that is useful, could you please help me out with the 1st and second paragraph of my question. $\endgroup$ Jul 20, 2021 at 2:09
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    $\begingroup$ I'm not sure what the 1000/3 refers to, are you talking about cloud clearances and visibility? Where do you see that written? $\endgroup$
    – Ron Beyer
    Jul 20, 2021 at 2:10
  • $\begingroup$ FAR 91.155 explains the different visibility and cloud clearance requirements for VFR operations in U.S. airspace. It also explains the applicability of "1000/3" (see FAR 91.155 (c) and (d). $\endgroup$
    – 757toga
    Jul 20, 2021 at 2:57
  • $\begingroup$ Related; and this question may help too $\endgroup$
    – Pondlife
    Jul 20, 2021 at 4:30

2 Answers 2


91.155(a) sets the VFR minima for the various classes of airspace in general. Note that “1000ft above” means the plane must be 1000ft above the cloud, not vice versa as you wrote. Also, the visibility here is flight visibility.

91.155(c) adds the additional requirement of a 1000ft ceiling within the lateral boundaries of controlled airspace designated to the surface for an airport.

91.155(d) adds the additional requirement of 3 miles ground visibility within the lateral boundaries of the surface areas of Class B, Class C, Class D, or Class E airspace designated for an airport.

91.155(c) seems moot at first glance, since 91.155(a) requires you to stay at least 500ft below the ceiling in class C, D and E airspace and 91.119(c) requires flying at least 500ft above the ground, but 91.155(c) prevents you from using the “Except when necessary for takeoff or landing” clause of 91.119 or the “open water or sparsely populated areas” clause of 91.119(c) as a loophole. It also prevents you from using the “clear of clouds” requirement in class B from flying VFR with a ceiling of 500-999ft.

The regulations don’t give an official reason why they are written the way they are, but there is a reason we say “the rules are written in blood.” For any given regulation, think about how you are likely to die if you break it, and you will probably find at least one matching accident in the NTSB archives.

Finally, for ceiling, we find in 1.1:

Ceiling means the height above the earth's surface of the lowest layer of clouds or obscuring phenomena that is reported as “broken”, “overcast”, or “obscuration”, and not classified as “thin” or “partial”.

  • $\begingroup$ Ok Im getting it more now. However, the fact that there is (I supposing) one ceiling only, shouldn't be necessary only to talk about 500' below ( I need to be 500 below the ceiling) how does it make sense to add another condition of "I need to be 1000' above clouds when there is supposed to be no clouds under the ceiling altitude right? thats is why is the ceiling, I am guessing. $\endgroup$ Jul 20, 2021 at 4:10
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    $\begingroup$ @YamchaAviator 91.155(a) refers to any cloud, not just the ceiling layer (if there even is one). It’s legal to fly VFR above or between cloud layers, and you can fly up or down through holes as long as you can maintain the proper clearance in all directions, which is unlikely if the layer is BKN or OVC. $\endgroup$
    – StephenS
    Jul 20, 2021 at 4:22
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    $\begingroup$ 91.155(d) might be considered moot in some circumstances, but if you want to operate VFR you must have 3 miles reported "ground" vis" (unless ground vis is not reported- usually, but not always, not the case for an airport in controlled airspace). Even if you have, in your judgment, 3 mi "flight" vis, but the official wx for the airport being reported is 2 1/2 mi ground vis then you cannot operate there VFR because the airport would be officially below VFR minimums. $\endgroup$
    – 757toga
    Jul 20, 2021 at 15:49

I don't understand why "the VFR min is 1000/3"

If someone is telling you that "the VFR min is 1000/3", then your confusion is warranted. For example, in the daytime in sparsely populated areas in Class G airspace there's no requirement that the ceiling (if present) be 1000' or higher, and you only need 1 mile visibility.


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