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Airspeed fittings?

Y

yankee-flyer

Well Known Member
This one peculiar to the -12-- I just purchased a UMA 21/4" airspeed indicator as a backup and it came with with two red plastic caps covering threaded holes for the pitot/static lines, but no fittings. What kind of fittings do I need to hook this up? Also, there's no indication of which should go the the pitot line and which to the static line-- or maybe it doesn't make a difference?? I'm hoping my ignorance can be cured. Thankes!

Wayne 120241/143WM
 
It makes a huge difference. If you look close you will see a P and an S. You need to T fittings. Vans has both. you also need the 1/4 line. I bought the 9' length Remove the straight fittings from the Dynon and move them to your ASI. Fit the T,s into the Dynon And cut lengts of the new tubing and run to your ASI. I just did this on my 12
 
Hi Mark, I recently fitted both ASI and altimeter in my -12, on the RH panel. I also purchased the nylon tubes and fittings from Vans. But the T fittings on their own would not do the job because of space requirements to curve the very stiff nylon tube. I solved the problem by buying two aluminium machined fittings from ACS that I bolted to the back of the firewall.

MANIFOLD AL FITTING FAB-1-0-2 04-00102 $9.40
 
I'm interested in this too, as I have already bought the ASI and Alt.
Rod, how much extra tubing do you need for both instruments?
 
Alton is right on the slip on fittings. It's the best way to go. By the way they are also sold at Mc Master-Carr. Don't know if there is any diff. in price.
Dick Seiders
 
Tubing required

Hi Robert,
I did not have to buy extra tubing. There were a couple of feet left over as well as a T fitting , a right angle fitting and a couple of straights. All I had to buy were a more straight fittings that were very inexpensive.
I reused some of the existing fittings. I cut the tube 1/4 in behind the collar and pushed the short tube through. They tested ok on reuse, but its not really worth it.
I could get some pics if you want. The front turtledeck is coming off this week for painting
The hardest part of planning the installation of the 3 inch gauges was minimising the cutout required in the aft flange of the fwd turtledeck

Rod
 
Rod

Thanks for the info. A photo would be useful, although my gauges are 2 1/4 and will go in the centre panel above the radio (Skyview panel layout). Shouldn't be too hard to work out, although I've still got a lot of building to do before I get to that point.
Cheers
R.
 
Thanks guys, but the original question was: What screws into the two threaded holes in the back of the ASI? Are those available from Steinair too?

Thanks

Wayne 120241
 
The 2 holes have 1/8 pipe threads. You screw the exact same type fitting into these that you are used to connect the pitot tube and static line to the Dynon. In the Vans catalog it is F N4MC-2 Nylon straight fitting. The T's I used are F-271-N-04X02 Nylon T (1/4 tube 1/4 tube 1/8 pipe). I'l try posting picture when I get back today.

In my case I remade the right hand instrument panel. I added a 3 1/8" Uma ASI , a 3 1/8" altimeter, a 2 1/4" fuel pressure and a 2 1/4 oil pressure ,and a Monroy ATD 300 traffic alert. I moved the map box to the right.

To install the ASI, I replaced the 2 straight fittings on the back of the Dynon with the 2 T's. There is plenty of room. Reinstall the existing pitot and static lines on the T fittings. Install the 2 straight fittings you took out of the Dynon on your ASI. Then you run 1/4" tubing from these fittings behind the radio stack and connect them to the appropriate T fitting. I pressure tested using the procedures in the construction manual and everything tested fine.
 
A couple of pictures of our dual SkyView installation (in the process of ground runs, not yet flown).

My 3 analogue instruments are a requirement for the UK:

UMA 2-1/4" ASI (40-160 kts)
Airpath C2300 Compass
FALCON ALTN10MBF-2 altimeter (single sweep 0-10,000ft....!)

ASI is plumbed with the pitot on the right and static on the left (gauge in the panel and viewed from the pilot's seat). Static T-piece also feeds the altimeter.

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003oap.jpg
 
Don't feel bad about the UK requirements, I am putting in the same analog instruments in with my Skyview. I like the way you have mounted them, looks very nice.
 
Be VERY careful screwing the fitting into the instrument. I once broke a UMA ASI by over tightening the fitting. The Stenair/Mcmaster fittings are GREAT. Don't bother with the cutter though, a sharp knife or scissors work fine, the tubing/fitting connections isn't really THAT sensitive to the cut.
 
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