When flying VFR, pilots are to stay free of clouds, which includes a minimum of 3 miles visibility, and 2,000 feet laterally.

Yet, I've seen some youtube videos where it appears the pilot gets too close to a "cotton ball" (a small, isolated cloud) simply because it is along his flight path.

If it is a very small, very isolated cloud, and you can see all the way around it, and have had good visibility on it for awhile as you approach, you know its not a "threat", right?

I suppose the FAA could violate you if you approach a cotton ball, but other than that, is there any reason to deviate and go slaloming around the sky just to keep distance from FEW clouds?

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    $\begingroup$ Related: How can I tell how far I am from a cloud? $\endgroup$
    – voretaq7
    Commented Apr 18, 2014 at 19:49
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    $\begingroup$ If you can't see through it, then yes. You need to avoid it because you don't actually know that there isn't a threat on the other side of it, headed towards you. $\endgroup$
    – Lnafziger
    Commented Apr 18, 2014 at 21:33
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    $\begingroup$ Your cotton balls are called "Cumulus humilis" a.k.a. fair weather cumulus. $\endgroup$
    – casey
    Commented Apr 19, 2014 at 2:06
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    $\begingroup$ "I suppose the FAA could violate you" - No. FAA staff are not allowed to violate(2) pilots. There are laws against that sort of thing. $\endgroup$ Commented Apr 19, 2014 at 7:30
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    $\begingroup$ @RedGrittyBrick "Sometimes it just feels that way." $\endgroup$
    – voretaq7
    Commented Apr 20, 2014 at 4:14

2 Answers 2


I suppose the FAA could violate you if you approach a cotton ball, but other than that, is there any reason to deviate and go slaloming around the sky just to keep distance from FEW clouds?

Aside from the legal reasons, keeping a healthy distance away from clouds is a Good Thing because other aircraft, birds, or alien spacecraft may pop out of them. Mid-Air collisions are no fun for anyone.

As far as going "slaloming around the sky", there's generally no reason to do that to avoid clouds:
If you're respecting the cloud clearance requirements (or at least the intent behind them) you shouldn't be getting close enough to clouds that you have to aggressively maneuver to avoid them - you've got plenty of distance to decide what you want to do.

Remember too that you've got 3 dimensions to work with: If we're only talking about a "puffy cotton-ball" or two you can always climb above or descend below them and stay on-course, or if they're all lined up inconveniently right along your flight path just offset your track a little bit (no reason to keep zig-zagging if a mile left or right of course keeps you clear).

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    $\begingroup$ That's not a good thing. I was planning to look for the giant's castle to get some gold coins. $\endgroup$
    – Farhan
    Commented Apr 18, 2014 at 20:17
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    $\begingroup$ I was wanting to get to Laputa! $\endgroup$
    – Jeff B
    Commented Apr 18, 2014 at 20:20
  • $\begingroup$ Glider pilots call rows of cumulus clouds "cloud streets". We fly directly underneath them to take advantage of the lift they generate; we can go long distances this way without needing to turn and without losing any altitude. If you see these along your path, consider staying beneath them rather than alongside them to fly a little faster and maybe save some fuel. soaringacademy.org/mtsafety/data/images/cloud-street.jpg $\endgroup$
    – KJP
    Commented Sep 1, 2016 at 20:23

The rules are there for a reason, and yet they are broken regularly. Here in Europe, on a nice day for cross-country glider flying, every pilot climbs up until he/she almost touches the cloud. Thermals go up into big cumulus clouds (your puffy little ones are baby cumulus - just wait, and some of them will become really big), and the center is normally higher than the fringes (the updraft is below the center and continues into the cloud, the fringes show downdraft - the rising air has to come down somewhere).

Updrafts get stronger the higher they are, so the last meters below the cloud give you the best energy increase, and the pilots use the last circle not for climbing, but for speeding up. Then they fly straight out from the thermal, through the puffy fringes and out into the open sky at high speed (for a glider, that is).

It just happens. A friend once told me that he was below a cloud, and right next to him a turboprop airliner descended from the cloud. However, that must have been a bad airliner pilot, because flying through a cumulus like this incurs a lot of avoidable turbulence.

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    $\begingroup$ I doubt most airliners would deviate for mere Cu. And not all thermals are maximal right under the cloud base- although extra height is just about always welcome. $\endgroup$
    – yankeekilo
    Commented Apr 21, 2014 at 20:51
  • $\begingroup$ @yankeekilo: Most airliners operate under IFR, so the issue doesn't come up in the first place. $\endgroup$
    – Vikki
    Commented Jan 24, 2020 at 0:06
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    $\begingroup$ @Sean especially for mixed IFR/VFR traffic this is relevant, as the IFR traffic can drop out of the ceiling. $\endgroup$
    – yankeekilo
    Commented Jan 29, 2020 at 22:23

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