Another map question; what is this triangle outside of Phoenix AZ

I was going through the a web site called MapOfStrange and found this:

great big triangle NW of Phoenix

The comments say that it’s an abandoned airfield, but that’s a really weird shape for an airfield. Anyone know about this?

It’s Luke Auxiliary Army Airfield #4. See the bottom section of this website: Abandoned & Little-Known Airfields: Northwest Phoenix area

(And in case you’re wondering, the racetracky thing to the west is the Toyota proving grounds)

The field is described in the previous link in references to Luke #4. (Frank Luke was an ace during WWI, noted as the leading balloon buster and a seemingly reckless fighter, for which the major Army Air Force field in the area was named.) There were multiple auxiliary fields scattered around for use as alternative or emergency landings. The odd shape was simply a convenient way to build them so that the pavers could simply turn and continue working until the field was completed without backtracking. (It also made it easier to spot from the air.)

As an auxiliary field, it had no buildings because it was not intended for maintenance or storage.

During the early years of aviation, it was considered necessary for airfields to have runways in multiple directions to avoid crosswind landings. Probably the majority of Army Air Force–era airfields have a vaguely triangular arrangement.

Here’s a not quite as perfect abandoned triangular airfield within the expansive grounds of Eglin Air Force Base in Florida. Presumably dates to World War II as well, the Doolittle Raiders trained at Eglin…

Another very common WWII aux airfield pattern looks like a wide A overlaid with a |.

i.e 3 runways forming about a 60-degree fan, with a single cross runway perpendicular to the center runway of the 3. The cross runway is usually about 2/3rds or 3/4ths of the way down to the open end of the 3-runway fan.

There are dozens, if not a hundred, of these things (3-legged As or plain triangles) left out in the rural areas of the mid-southern US from CA to KS & TX to GA. They’re just cement and graded dirt slowly merging back into the arid natural landscape. I see them all the time while flying, but can’t now locate a good example of an A-frame; they’re common enough that I don’t recall where any specific one is located on the ground. And it’s impractical to just scroll Google maps across Kansas scanning for one.

Pretty much every WWII flying training base had between 3 and 10 of these things scattered withing 20-30 miles of the main field.

Here Google Maps is another example which is also an aux field from Luke AFB. This one is still in use as an emergency landing field for the nearby Luke bombing range. In 1985 a friend of mine bailed out of a damaged jet there. One runway has been extended to be long enough for modern aircraft. And because modern aircraft are much more crosswind-tolerant than the taildraggers of WWII; the other runways were abandoned. They’ve deteriorated past the point of usability now.

My dad was a Flight Service Specialist at Barstow-Daggett Airport. It has two paved runways, but you can clearly see the abandoned dirt strip that forms the eastern side of the triangle. DAG was built in 1933, and was used by the USAAF in WWII.

Alas, it looks like the pool is no longer used. But the fishing lake is still there.

I think you meant to link to here. Did you copy the URL from your browser after following LSLGuy’s link?

If you go south east from this field, you will find the remains of another field and just to the SE of that is the former Volvo (now Ford) Arizona Proving Grounds

Apparently my link doesn’t work either, but that’s Google’s problem. If you click, then click “Search Map” it works for me.

I hadn’t looked at the site in GreasyJack’s most excellent post #2. My mistake.

Starting here Abandoned & Little-Known Airfields: Northwest Phoenix area there are a bunch of pix of both triangle and A-frame aux airfields.

As I said above, Luke is/was hardly unique in having a bunch of these. If I can remember, I’ll post a Google maps link here next time I encounter some not in the greater Phoenix area.

Here is the correct link.

Here’s another one, still active for general aviation. Three 4500-foot runways, built by the US Navy in 1944 to train army pilots. Only the 3/21 and 15/33 runways are maintained, with the 9/27 r/w having had a residential subdivision built on its eastern approach zone, and having had its surface degrade so it was too expensive to resurface it. BTW, in case you’ve ever wondered how they number runways, add a zero after the numerals and you get the compass heading. I never knew that until I managed such an airport for several years. The one near Phoenix appears to havehad three 4,000 foot runways.

I notice 9/27 has none of the big “X” markings you usually see down the centerline of a closed runway. Airnav lists 9/27 as an active runway in “fair” condition, albeit the markings are noted as “poor.”