Pitot hose transition

[Rick6a]

It is generally accepted that it is best to keep bends as gradual as possible when routing hose from the pitot tube to the back of the instruments. Still, it would certainly ease installation if I terminated the soft aluminum tubing from the pitot tube into a right angle bulkhead fitting (installed in the fuselage) then continue the run to the back of the instruments with plastic or nylon tubing. Is this an acceptable plan, or is that right angle bend in the bulkhead fitting just too severe for this application?

[plehrke]

There is no air flow in the pitot (or static) system and therefore you do not get losses due to sharp turns. It is pressure only.

[pvalovich]

I have run 1/4 inch aluminum tubing from the heated pitot to the wing root, where it attaches to the type fitting shown in the picture. However, I cannot get the supplied plastic tubing to fit on to the fitting . I'm thinking of using 3/8 tubing as a transition sleeve.What did you guys do?

[Captain_John]

I have been noodling over this "transition fitting" from the flare fitting on the pitot tube to the nylon tubing that will run through the wing.

This is what I am thinking:



My buddy Rich is a machine guy and it is in his lap right now. If he were to whip up some of these, would anyone be interested?

Maybe a "BULK OFFER" could be done? Not a "GROUP BUY"!



Hahahaha... I crack myself up!

CJ

[gasman]

Originally Posted by pvalovich

I have run 1/4 inch aluminum tubing from the heated pitot to the wing root, where it attaches to the type fitting shown in the picture. However, I cannot get the supplied plastic tubing to fit on to the fitting . I'm thinking of using 3/8 tubing as a transition sleeve.What did you guys do?

JUST FLAIR the plastic tubing..................... it does work

[Bob Axsom]

I used a bulkhead elbow with the right angle end outside the fuselage. This orientation made all of the fittings easily accessible for disconnect at the wing root. Inside the fuselage I used aluminum tubing that smoothly curves back to the lower left corner of the fuselage then forward to the firewall and up to the instrument. The only place I recall using plastic tubing was in the static system. As has been stated before there are no inacuracies resulting from the "L" fitting.

Bob Axsom

[az_gila]

Anyone see anything wrong with using a flexible Polyurethane tubing. The tubing is rated from -50F to 175F or so....

Doesn't SafeAir use something similar in their pitot/static/AOA kit?

Note.. not PVC (vinyl) tubing which will "creep" and become loose at not so high temperatures...

One example here...

http://www.usplastic.com/catalog/pro...duct%5Fid=8115

...also colored as a more expen$ive option....

gil A

Merry Chrismas to all...

[jmartinez443]

Originally Posted by pvalovich

I have run 1/4 inch aluminum tubing from the heated pitot to the wing root, where it attaches to the type fitting shown in the picture. However, I cannot get the supplied plastic tubing to fit on to the fitting . I'm thinking of using 3/8 tubing as a transition sleeve.What did you guys do?

Here's what I did:

And lastly, here is the plastic tubing that will attach to the hardline and penetrate the fuselage on it's way up to the panel.
I used an AN 807 (adapter hose to universal) fitting. Here's the link to spuce's page: http://www.aircraftspruce.com/catalog/hapages/an807.php.

Here's the trick I used to get the hose on the fitting:

- first I cut off the bead at the tip of the fitting since it would be a challenge to get a piece of tubing with the same dimension as the fitting to slide over said bead.

- I then cut a thread on the fitting to give it some bite.

- Then I heated the hose as I threaded the fitting. Be very conservative with the heatgun as you don't want to melt the hose. Heat then thread a couple of turns, then repeat. That hose ain't coming off.

[Finley Atherton]

Originally Posted by pvalovich

I have run 1/4 inch aluminum tubing from the heated pitot to the wing root, where it attaches to the type fitting shown in the picture. However, I cannot get the supplied plastic tubing to fit on to the fitting . I'm thinking of using 3/8 tubing as a transition sleeve.What did you guys do?

I used the softer and more flexible 3/8” O.D X ¼” I.D. tygon tube (available from ACS). I simply pushed the tygon tube a couple of inches or so over the aluminium tube, ran the tygon all the way up to the ASI and used a Polyethylene barbed hose fitting (from ACS) to hook up to the ASI. I had the pitot system pressure tested for certification with no leaks. I did not use any hose clamps, however a hose clamp at the aluminium tube to tygon tube join might be a good idea. One word of caution. The tygon is softer than the nylon tube so avoid sharp bends or the tygon may kink. Also a tightly pulled up cable tie around the tygon could close up the tube.

Fin 9A
Australia