FlyingBulldog

Thanks, I think that's about the best answer there is to my question. Interpolation is the key... I guess just using FA, nearby ATIS info, and whatever else I can get my hands on will have to do. I was just curious if there were any rules like "use the weather of an ATIS within X miles", or anything like that, and I guess there isn't.

Singlecoil

You seem to be looking at this from the angle of how cam you prove that you were operating legally. In some scenarios like this it might be more helpful to look at this from the angle of how someone else could prove you were not operating legally.

FlyingBulldog

That's a good way to look at it.

Yoda2

The "Test" for many things, especially aviation related, is "What are they going to say at the hearing?" If you have a good answer, you're generally "Good to go..."

joepilot

There is one thing that I have not seen anybody mention: The day VFR minimums in Class G airspace are 1 mile and clear of clouds. It is fairly straight-forward to estimate visibility by knowing your runway length, and observing how far down the runway you can see. If you can see the end of a runway that is a mile or more in length, you are legal to go. It is somewhat harder with shorter runways, especially if there are trees off the end, but it is a yardstick to use.

Joe

JohnBurke

While legal, one mile visibility when IFR is no problem; when flying VFR it's foolish.

FlyingBulldog

Yes, one mile would be a little ridiculous. For VFR, I'd consider even 3 miles a little low.

joepilot

It depends on the speed of the aircraft. In a King Air or a Lear, no way. In an ultralight with a 20 knot stall speed, no problem.

Joe

JohnBurke

Either way you're dealing with the other bright sparks out there that are flying around in low visibility. Far better to go IFR.

TimetoClimb

You are missing the mark here on a few points. Let me try to clarify to the best of my understanding.

First off: TAF's are good to 5 miles radius I believe , FA are good for interpolation as the others mentioned.

BUT; It's Class G were talking about here, and the VFR minimums during the day are 1mile vis and clear of clouds.....without a specific ceiling requirement imposed.
91.155(c): "except under {special vfr}, 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 1000 feet."

The 1000' ceiling of basic VFR applies to CONTROLLED Airspace. Class G is, as you have said, is uncontrolled. Therefore, you can putt around in the pattern under VFR and maintain the 1 mile / CC and not worry about the ceiling or the weather reporting. Heck, you don't even need to talk to anyone while you're out there doing it! Idiotic, but legal.

Controlled Airspace and Weather reporting are interdependent.
Class G is the wild west.

91.155(b)(2) which you bring up refers to night operations in class G when near an airport. It is written like that so pilots can perform night training and currency flights when their is a low, but not hazardous overcast layer at night.

Also , note, that there are no specific minimum weather requirements for IFR in class G under part 91. Meaning, if you are instrument rated and current, you can legally launch into Zero-Zero in class G as long as you get a clearance before entering controlled airspace, or prove that you were VFR upon entering the overlying class E (aka 3 miles and 152's).

Flying around in zero zero below a C shelf is a horrible idea and they will get you for careless and reckless operation if anything were to go down. Also, you have to maintain minimum obstacle clearance requirements under IFR unless arriving or departing.This is in 91.177: 1000' in non-mountainous and 2000' in mountainous areas... so you can't legally stay in the pattern below a mile vis, or in clouds.

See AIM 3-3-3, my DPE specifically asked me about this on the Oral.

Does this clear anything up?