Airfield Tetrahedron Design Information Request

ProfromDover · **Posted:** Thu Dec 12, 2013 4:15 pm

All,

Wondering if some of you fine folks have any design data for building an airfield tetrahedron. All of our research in the FAA side of the world has got us zip. Tets are referenced in FAA documents but the FAA only currently gives guidance for windsocks. The FAA apparently doesn't consider tets current technology. I checked with TxDOT and they came up with goose egg also. Hmmm.

Does anyone have any USAAC, NAVAIR, SeaBee's, MilSpec, etc. info on building a tet? Every military field had one in the 40's. There's got to be something out there.

We can build one off of pictures but we thought it would be nice to accurately replicate a proper WWII tet. We had a homebrew tet but it finally rotted and we need to build a new one. Any help will be appreciated.

Thanks!

cco23i · **Posted:** Thu Dec 12, 2013 5:52 pm

Have you checked with the research area of the Air Force Museum?

Scott

ProfromDover · **Posted:** Thu Dec 12, 2013 5:59 pm

Not yet. Haven't gotten that deep. Up until now I thought it would be easier!

The Inspector · **Posted:** Thu Dec 12, 2013 7:15 pm

A pretty easy item to make, either an accute or isosceles trangle from two 4 X8 sheets of 3/4 inch exterior plywood and a box of exterior wood screws and some pipe.
An airfield in the GWN in the NWT uses an ex RCAF C-47 as a wind sock :lol:

dinghao · **Joined:** Wed Feb 20, 2013 7:40 pm **Posts:** 47

There is one in a private junkyard just NE of the runway at the former Kelly AFB. Might be Alamo A/craft supply Co. Shows up on Google maps too.

RareBear · **Posted:** Thu Dec 12, 2013 9:51 pm

Check out this summary of patents for airfield tetrahedrons, with links to other patent info.

Walt

http://www.google.com/patents/US5323649

walkerarmyairfield · **Joined:** Wed Feb 13, 2008 12:10 pm **Posts:** 58

Bill,
There are two of the original WW2 B-29 training airfield tetrahedrons still in use near me. One is on the Pratt Industrial Airport (Pratt Army Airfield) (PTT)also one on the Great Bend (GBD) Kansas municipal airport. They are both in the original WW2 locations. Great Bend's was removed at the request of the great FAA for a short period of time until the locals raised cain and put it back with volunteer labor on its original mounting. The Great Bend guys had to have a new brass shaft machined for theirs and the original came up missing during the short time the tetrahedron was removed.

I have photos of the ID Plates on both of them, will look for them. These are the big ones. Made by a company in Chicago during the war. Singer is the mfg name that comes to mind but I want to find out for sure.There is a smaller one on the Herington Kansas airport. Herington's appears to have been moved from its original location.

I will be going to Great Bend in the next few days and will take a photo of the ID plate on the tetrahedron if I don't find the photos in my records.

These show up for miles and are great to have on an airport due to their large size.

Phillip

Rauhbatz · **Posted:** Fri Dec 13, 2013 6:15 am

Hi Bill...if you look at Google Earth for the Zanesville Ohio airport where we are restoring the F 105, there is a very laarge tet that the center of the field. While doing the F105 painting i went over and looked at it. It appears to be built many years ago when this airport was used for a short while to fly injured into local hospitals during WW2.

Next trip out there I will see about any plates/details...would be interested in a post here on what you find out.

BTW when I fly into ZZV i use the tet all the time to pick a runway....

walkerarmyairfield · **Joined:** Wed Feb 13, 2008 12:10 pm **Posts:** 58

Took a few photos of the Great Bend (GBD) Kansas airport tetrahedron this afternoon. The former B-29 training Army Airfield.

The Data Plate is still on the mounting under the tetrahedron, has the following data on it.

MFG by Garden City Plating & MFG Co. Chicago, Ill
Spec AN-1-1
Order number 42-15741
Property of the United States Government

Will try to post some photos of the Data Plate and the Tetrahedron.

Phillip

Matt Gunsch · **Posted:** Fri Dec 13, 2013 8:13 pm

Rauhbatz wrote:

BTW when I fly into ZZV i use the tet all the time to pick a runway....

Isn't that what you are supposed to do ?

ProfromDover · **Posted:** Fri Dec 13, 2013 9:37 pm

Ding ao,

Do you know if Alamo Surplus in SA will let you roam their yard? Looks like lots of stuff out there...

ProfromDover · **Posted:** Fri Dec 13, 2013 9:50 pm

Scott, Received your PM. Thanks much for the help and pix!

All,

I checked out some of the referenced aerial shots of tets and they all seem to be about a 3 to 1 ratio length to width (and huge!). Mount seems to be at about the 40%(ish) position from the front. I have some preliminary sketches made and will keep you abreast of in process pictures of fab. I have a preliminary materials list developed and will refine as we progress.

We're laying out about a 16' length tet with a 6' width at aft end. A nice size for our 3000' local field.

Thanks!

bdk · **Joined:** Sun May 02, 2004 1:16 am **Posts:** 11324

Couldn't find any MIL-SPECs for one...

Chris Brame · **Posted:** Sat Dec 14, 2013 4:01 am

dinghao wrote:

There is one in a private junkyard just NE of the runway at the former Kelly AFB. Might be Alamo Aircraft supply Co. Shows up on Google maps too.

Aha! Gotcha, ya lil' devil:

Rauhbatz · **Posted:** Sat Dec 14, 2013 6:11 am

Hi Matt....in respect to the ZZV tet I'm conditioned to look for wind socks which are found at just about all airports....first time I flew into ZZV I was pleasantly surprised to find that big friendly triangle staring up at me....

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