[Pmerems]

Fellow builders with Dynon AOA pitot tubes.

If you haven't installed your AOA pitot tube yet please inspect the tube. If it looks like the one pictured below, it is improperly manufactured.

I just received an RMA from Dynon because my pitot tube (pictured-left side) has the forward tube too far forward in the assembly. This condition makes it almost impossible to drill and tap the forward screw bosses without the possibility of damaging the forward tube. Some builders may have carefully drilled their pitot tubes to remedy this issue but these are improperly manufactured (per Dynon tech support). Contact Dynon tech support for a RMA if you have a improperly manufactured pitot tube like mine.

I have set up this pole to help determine what percentage of pitot tubes that are affected.

 

[kiwipete]

Interestingly when I installed mine I scraped out the RTV and moved the tubes back before putting new RTV in because I wasn't happy with the tube location.

Peter

 

[Dynon]

These are not "improperly manufactured." Due to the way they are built and assembled, the location of the tubes coming out of the top is not really well controlled. Sometimes they end up near the front, back, or middle.

There is nothing wrong with a pitot with the tubes near the front. They work fine.

We understand that this makes drilling and tapping a bit more difficult in some cases, but we've sold thousands of them this way with no problems. With a mark of tape on your drill bit and tap, you should be able to drill and tap these with no problem. Even if you nick the aluminum tube, it doesn't matter until you actually breach the wall. Even if you did this, the leak would probably be so small you'd never notice it.

If you are really concerned and feel like you can't do this, then please call us and we will swap it out. But please don't call and ask for a replacement just because this has been called "defective." The pitot still works fine.

If you do attempt to drill it and it gets messed up, we'll swap that out too.

 

[kentb]

Thanks, DynonSupport

These are not "improperly manufactured." Due to the way they are built and assembled, the location of the tubes coming out of the top is not really well controlled. Sometimes they end up near the front, back, or middle.

There is nothing wrong with a pitot with the tubes near the front. They work fine.

We understand that this makes drilling and tapping a bit more difficult in some cases, but we've sold thousands of them this way with no problems. With a mark of tape on your drill bit and tap, you should be able to drill and tap these with no problem. Even if you nick the aluminum tube, it doesn't matter until you actually breach the wall. Even if you did this, the leak would probably be so small you'd never notice it.

If you are really concerned and feel like you can't do this, then please call us and we will swap it out. But please don't call and ask for a replacement just because this has been called "defective." The pitot still works fine.

If you do attempt to drill it and it gets messed up, we'll swap that out too.

I'll need to check mine to see if I screwed it up, I don't think so.

Kent

 

[John Courte]

Mine's kinda like that,

But worse.. the tubes are a little off to the side as well. But it's not a showstopper, I don't think.

My biggest concerns are lining the drill up perpendicular to and centered on the screw bosses. I'm still puzzling that one out. And what type of screws? Not sure yet. I was thinking about drilling through the thin part and using countersunk blind rivets. There are plenty of places around the rim of the fixture there to put blind rivets in. Unless that's a no-no.

I can't remember if there was mounting hardware with the Pitot/AoA probe or not. I don't think so.

 

[craigvince]

Heated

On mine, the tubes are far enough back, but the wiring is right where the screws go. I don't think it will prevent me from being able to use it, though.

 

[Pmerems]

What Dynon tech support told me

These are not "improperly manufactured." Due to the way they are built and assembled, the location of the tubes coming out of the top is not really well controlled. Sometimes they end up near the front, back, or middle.

There is nothing wrong with a pitot with the tubes near the front. They work fine.

We understand that this makes drilling and tapping a bit more difficult in some cases, but we've sold thousands of them this way with no problems. With a mark of tape on your drill bit and tap, you should be able to drill and tap these with no problem. Even if you nick the aluminum tube, it doesn't matter until you actually breach the wall. Even if you did this, the leak would probably be so small you'd never notice it.

If you are really concerned and feel like you can't do this, then please call us and we will swap it out. But please don't call and ask for a replacement just because this has been called "defective." The pitot still works fine.

If you do attempt to drill it and it gets messed up, we'll swap that out too.

Since I started this thread I want to make sure everyone understands exactly what Dynon support told me over the phone when they saw the image of my pitot tube.

"This is wrong, I typing in your RMA right now, send it back and we will send you a new one". Eric at Dynon was looking at the picture of my pitot tube on the forum and I thought he acturally replied to the posting at that time. This was the day earlier in the week that this site had some maintenance performed and the forums were acting up. I don't know if Eric tried to post or not. He was very helpful and we discussed how hard it would be to drill and tap the tube and the consequences of possibly damaging it. He handled this issue very professionally.

I want to make it clear that I never said these were defective just improperly manufactured. As some builders mentioned they were able to drill/tap and make it work. Some cut out the RTV and moved the tube. However when I purchase a quality product I don't expect to have to rework it to make it right. After talking with Eric at Dynon's tech support I believe this is Dynon's position as well.

Dynon makes really great products. If I see something that isn't right I want to help make it right. Since Dynon support told me it was incorrectly manufactured I passed the word out to you all.

 

[az_gila]

Drill in a drill press

But worse.. the tubes are a little off to the side as well. But it's not a showstopper, I don't think.

My biggest concerns are lining the drill up perpendicular to and centered on the screw bosses. I'm still puzzling that one out. And what type of screws? Not sure yet. I was thinking about drilling through the thin part and using countersunk blind rivets. There are plenty of places around the rim of the fixture there to put blind rivets in. Unless that's a no-no.

I can't remember if there was mounting hardware with the Pitot/AoA probe or not. I don't think so.

Short 6-32 pan head screws are recommended. I was able to put both the mast and the pitot in my cheap HF drill press vise and hold them at the correct angle to keep the drill bit square to the spot being drilled. Made making the holes easy.

It was no big deal, and I even did a second one for the local RV-8 guy who got my extra Dynon pitot - don't ask...

BTW, the tubes were away from the drilling locations in both pitots.

gil A

PS ...since I did 2 pitots, there should be an extra vote for "Unheated tube- Correctly Manufactured", But DR won't let me vote twice...

 

[John Courte]

Short 6-32 pan head screws are recommended. I was able to put both the mast and the pitot in my cheap HF drill press vise and hold them at the correct angle to keep the drill bit square to the spot being drilled. Made making the holes easy.

It was no big deal, and I even did a second one for the local RV-8 guy who got my extra Dynon pitot - don't ask...

BTW, the tubes were away from the drilling locations in both pitots.

gil A

Thanks, Gil!

I think i've got that hardware handy, and my drill press does all sorts of
contortions, so I should be able to do it that way, but I'll probably wind up
digging out the RTV.

As to the 'improperly manufactured' question, maybe it's not improperly
manufactured, but it sure doesn't help to have to work around it,
or send it back for one that isn't problematic.
Call it a quality control issue. Seems to me a little rubber form that
holds the tubes in the right place before all the RTV gets squirted in
there wouldn't add more than about a buck to the manufacturing
process, in time and materials.

 

[cytoxin]

mine is off a bit

the heater wires are touching the boss's, but i'll try to work it out...at worst i'llpull the potting (looks like silicone to me) out bend them back and go again...i am a little concerned about damage to it but if DYNON says they'll fix it i m good with that. really shouldnt be a problem though.

 

[GAHco]

Screws

Most certified aircraft use 6-40 screws

I don't know why but that is the way it is.

IMHO either would work as long as you are gentle and not a wobbly hadner person while tapping.

Do not over tigheten.

 

[lostpilot28]

Doh! So I sent in my Dynon AOA pitot probe to get it replaced because the tube in the front was pretty much making contact with the screw boss on the left. The one they sent me as a replacement was EXACTLY the same!

I think I'll try to make it work as is, and if I screw it up (pun intended) then I'll send it back again.

 

[Bill Dicus]

Dynon pitot

The heated pitot they sent me is closer to the "good" pic than the "bad." It appears that it can be drilled/tapped safely. Haven't done it yet. Bill