Hi everyone.

My family owns a 40 acres field in the French Alps, and I've always dreamed of building a small airfield on it.

I'd like to do a low budget survey to learn more about prevailing winds and general weather conditions. I was thinking about buying one of these cheap weather station off Amazon with a built-in memory and interpolate the data after a year or so.

Do you guys have any experience with this, or recommendations?

Thanks!

I've found the cheap ones to be pretty unreliable. I'd be looking at weather history for the area instead.

rw2 wrote:I've found the cheap ones to be pretty unreliable. I'd be looking at weather history for the area instead.

Maybe this particular spot has some quirks, maybe caused by terrain or whatever.

I think if you can find something that will upload data to a reliable network storage, it would be good. I don't think I'd leave a recording device in the field for months at a time.

If your area is windy enough to be a concern on building a runway look at mature trees or hydro poles they will have a slight lean from the prevailing winds.

I expect you have considered any slope of runway difference, any border without obstacles, down drainage egress, and length of surface. Wind management is a major consideration but neither the only consideration nor sometimes the most important consideration.

Back in the pre-GPS days, when the only precision instrument approach available was an ILS, there was a desire of some of the regular users of the Laramie airport for us to seek funding for an ILS. The only approaches were a VOR approach to 12 and a VOR/DME step-down approach to 30. I was chairing the Airport Board at that time, so I started looking at the requirements. The first thing that the FAA required to participate was a wind study, because the two major criteria for an ILS were prevailing winds and runway length. At that time, 21 was 7700' long; 30 was 6600' long. Both qualified, depending on which one had the prevailing winds.

We ran on a very lean budget, and so the Board elected not to go ahead with a wind study, which was going to cost around $16,000 in 1980 dollars (about $50,000 today). The Director of one of the major users, the University of Wyoming Department of Atmospheric Research, was adamant that 21 was "the" runway of choice, and it was hard to convince him that being adamant wasn't going to cut it with the FAA--we needed formal wind study, and we couldn't afford to pay for it. He then offered that if the University conducted the study to FAA standards and proved that 21 was the runway of choice as he believed, we could pay the University back in payments over a 10 year period. If 30 turned out to be the runway of choice, then the University would eat the entire cost of the study.

I don't recall that the study took a year--I'm thinking 6 months. But whatever length it was, it turned out that 30 actually was appropriate runway, not 21. As many of us thought, the real prevailing wind at Laramie tends to split the runways, but also tends to favor 30.

We still couldn't afford an ILS. The FAA would install it bearing the lion's share, 90 or 95%, but they required a larger percentage contribution each year to the maintenance of it, and that was the sticking point. So there never was an ILS at Laramie. Now, because they cost so little by comparison, both to create and to maintain, it has GPS LPV approaches to all of the runways; and it still has a VOR/DME approach to 30, and the VOR to 12 has been improved to being a VOR/DME.

I tend to think David's idea of which way the trees bend has merit--unfortunately, there are very few trees around the Laramie airport!

Cary

I was searching for something else, and this doc came up. While not specific to Prevailing Winds - its on HOW TO BUILD YOUR OWN AIRSTRIP commissioned by the Dept of Transportation for state of Texas. Anywho... thought it might be of some use to you.
https://www.mdt.mt.gov/aviation/docs/sample-texas-design-guide.pdf

When setting up my rwy, I looked at all the public use airports within 50nm. All had 17/35 as the sole or main rwy. I used that, and it works fine.