Help me solve this DIY AOA dilemma

I'm running the plastic tubing from the Dynon D100 to use the AOA, and using the DIY AOA idea from Mel. I like the idea of "marrying" the AOA tube to the pitot.

But I didn't want to just run aluminum straight up into the bay, especially with the aileron bellcrank assembly possibly in the way, so I side stepped a bit and installed a bulkhead fitting into the inspection panel with the idea that I'd run a short piece of aluminum tubing from there into the neighboring bay where it would be connected to the plastic tubing with a quick connect/disconnect, making it relatively easy to remove the inspection panel.

For aesthetics and security, I wanted a nipple on the inspection panel, like so.



Unfortunately, I've been unable to come up with a way to do this without it interferring with the aileron bellcrank or the aileron tube. I even thought about just making a short 90 degree bend, turning it outboard, snake the plastic tubing along my conduit for wiring and then turn the tube back and into the quick connect, but the darned bulkhead fitting is just too high and you can't make a sharp enough bend in the aluminum tubing to keep from hitting the bellcrank or tube.



I'd rather not add a separate tube/probe further outboard, but I could, and maybe put a doubler on the inspection panel, but I'm wondering if there's a simpler, less weighty solution. I couldn't find a shorter AN bulkhead fitting so I'm kind of stuck and am looking for inspiration here.

I made a new inspection cover using .063" material. My plane is a 6A so I'm not sure of the bellcrank interference differences. I would turn your bulkhead fittings around for clearance, see mine in the photo. I took a couple of short pieces of copper tubing and drilled a hole in the fitting and JB Welded the tubes in. I used Tygon tubing for my pitot - static lines which fit on the copper tubing good. I copied the probe Mel made also and it works beautifully.

I have since removed the Piper blade probe.

I think the 6A is different because the bellcrank will interfere . Not sure what you mean by turning the bulkhead fitting around. It's a straight fitting. It's that it's too long so even if I turn the 90 degree bend in the AL tubing, it's still going to hit the bellcrank or tube. The pitot fitting fits through the main spar web and isn't moveable.

I suppose I could relocate the probe by moving it over one bay, but then I can't mate the pitot and AOA tubing as you have done and -- unfortunately -- I have done. Of course, easy enough just to make a new pitot and forget the AOA but I'd like to see if there's a solution here before I go that route.

Substitute the bulk head fitting with a 90 degree bulk head fitting, should solve the problem.

Hmm. I'm looking at a picture of a 90 degree fitting and from what I can tell, that puts the nipple at 90.degrees on the exterior bit maintains a straight fitting in the problematic area. I could turn it aroing and have the longer part of the bulkhead fitting on the outside but, man, that would look ugly.

Bob,

This is a photo of my version of Mel's AOA pitot (faired with fiberglass). It consists of two Al tubes that go through a piece of 1/2-inch Aluminum that is shaped aerodynamically (see top of photo) and screwed to the inspection plate from above. The Al tubes are well behind the bellcrank because of the attachment angle and I simply put plastic tubing over the ends and routed to the instrument panel from there. Difficult to see the AOA probe in this photo, but its directly below the curved pitot and cut at about 45 degrees.

Cheers,
Greg

Bob,
If you have access to a lathe it is easy to cut down a straight bulkhead fitting and remachine the taper. The 90 degree fitting is a little harder to do, but not by much. I can do this for you ----let me know.

Stewart Willoughby
6, finishing.

Can I send one to you?

Just bumping up the thread for one last try. Stuart's going to cut down a bulkhead fitting, but if that doesn't work, looks like I'll just pull it all out. But wanted to give it one last try.

I'd like to quickly give a shoutout to Stewart who sent me a modified bulkhead fitting. He donated his own. And if it doesn't provide enough clearance, he's going to make one for me with a barbed tip for attaching the plastic hose directly.

Flying was fun, but this is the kind of stuff I'm going to miss by not being in the RV community.

If you read this RV12 thread, you will find that the Dynon AOA works fine using one-eighth inch tubing. (And even no special pitot!!!) A quick disconnect barbed fitting works. The parts list from McMaster Carr includes these. Many have installed it this way. The one-eighth tubing bends in a short radius. http://www.vansairforce.com/community/showthread.php?t=34040

Stewart sent me this cut-down bulkhead fitting that he machined.



We'll see if I can get the nut and the B Nut on. If not, one other thought is to JB Weld (it's a verb, right?) it onto the inspection plate.

I think it'll clear. If not, I'll go the barbed fitting route.

Yahtzee! It fit.



Now I've got to find someone to babysit me me while I fly to the test area to calibrate it.