Question applies to operating an Airplane.

The part 91 regulation regarding Basic VFR weather minimums in Class G airspace states (in the FAR 91.155 chart):

For aircraft other than helicopters:

Day, except as provided in 91.155(b): 1 statute mile and clear of clouds.

When I refer to 91.155 (b) I don't see any exceptions pertaining to airplanes operating in Class G airspace during the day. The exception noted for airplanes only pertains to night time.

Is there some reason this regulation indicates that an exception does exist for daytime operations?


1 Answer 1


CFR 91.155(b)(2) has the exception:

(2)Airplane, powered parachute, or weight-shift-control aircraft. If the visibility is less than 3 statute miles but not less than 1 statute mile during night hours and you are operating in an airport traffic pattern within 1/2 mile of the runway, you may operate an airplane, powered parachute, or weight-shift-control aircraft clear of clouds.

So if the visibility is less than 3 statute miles (not less than one statute mile at night), you can operate in Class G as long as you are clear of the clouds and within 1/2 mile of the runway. It does not mean that the entire exception applies at night, only that at night, you need to have at least 1 mile of visibility, otherwise during the day you can operate down to nothing as long as you are clear of the clouds.

  • $\begingroup$ Thanks, but I'm not certain what you mean by "... otherwise during the day you can operate down to nothing as long as you are clear of clouds." Also, the regulation seems unambiguous that during the day you only need 1 mile visibility and you do not have to remain within 1/2 mile of the runway. $\endgroup$
    – user22445
    Jun 16, 2017 at 13:57
  • $\begingroup$ No, it is "not less than 1 statute mile at night", during the day if you are within 1/2 mile of the runway, you can operate at less than 1 mile of visibility. The regulation is hard to read, but it allows you to operate less than 1200 AGL and any visibility less than 3 miles during the day. At night, you need at least 1 mile. $\endgroup$
    – Ron Beyer
    Jun 16, 2017 at 13:58
  • $\begingroup$ So, you are saying that during the day, an airplane can operate (class G, below 1200 ft agl) with "...any visibility less than 3 miles?" This would mean that if there were, for example, only 1/16th of a mile visibility I could fly during the day (class G, below 1200' agl)? I can't see that the regulation is saying this. $\endgroup$
    – user22445
    Jun 16, 2017 at 14:09
  • $\begingroup$ The implication is that you need to have visual contact with the runway to maintain the 1/2 mile distance, but yes, you could operate within 1/4 or 1/8 mile of the runway if you are capable of making a pattern that small. That means the slower aircraft (a 150 for example) can run really tight patterns at low visibility in Class G, not that it would be a great idea, but the regulation allows it. $\endgroup$
    – Ron Beyer
    Jun 16, 2017 at 14:11
  • $\begingroup$ Ron, I appreciate the effort you have made to answer my question. The unidentified "exception" could be a remnant from an earlier change not removed. Perhaps there is another explanation. However, I strongly encourage you to do some additional research prior to ever operating an airplane, under VFR in any class airspace (G included) day or night, with less than 1 mile visibility. The FARs prohibit this in spite of your proximity to the runway. Not only would flying a VFR pattern with 1/8 mile visibility be incredibly hazardous but you would find yourself in violation of the FARs. $\endgroup$
    – user22445
    Jun 17, 2017 at 17:53

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