Pitot tube routing

RVNewsletter · Post by **RVNewsletter** » Mon May 17, 2010 7:48 pm

So, I've got this aluminum tubing coming to the wing root rib and I've got this SafeAir green pitot tube.

Questions abound:

1) What's a good way of connecting the aluminum tube to the plastic tube?
2) Where should it come into the fuselage?
3) How should it be routed once in the fuselage. I've got no passthroughs available through -- one is filled with manual trim cable. The other is filled with wires.

RVNewsletter · Post by **RVNewsletter** » Tue May 18, 2010 10:05 am

Seriously? No response? Nobody's ever built an RV-7A before?

Post by **Spike** » Tue May 18, 2010 1:40 pm

Actually Ill move this over to the general questions area since its not specific. We might get more eyes. I want to see it answered too.

Spike

BSwayze · Post by **BSwayze** » Tue May 18, 2010 2:28 pm

Me, too. My aluminum pitot tube terminates at the wing root using one of these blue AN fittings. I'm not there yet, but I'm wondering the same thing.

cjensen · Post by **cjensen** » Tue May 18, 2010 9:43 pm

Maybe it's an "A" thing, but why is there an AL tube? Can't run the green tubing all the way to the panel? That's how mine is routed...

RVNewsletter · Post by **RVNewsletter** » Wed May 19, 2010 7:26 am

The AL tube is what the plans call for. The problem is that Van's does not address the pitot run at all in its plans. Most folks build the wing and run the aluminum tube and leave a bunch sticking out of the wing root, assuming that there'll be guidance later on. There isn't.

What I did last year was cut the aluminum tube and put a bulkhead fitting on the wing root, figuring I'd make some connection later on. It's later. And when I mated the wing the other day, I realized that bulkhead fitting isn't going to work. It's too long, doesn't allow for a graceful "S" into the fuselage and, besides, it's a -4 fitting.

I bought this SafeAir kit (the green tubing) primarily for the static ports but the pitot stuff came with it.

The problem is the aluminum tube requires -4 fittings and the SafeAir connection is a -3 fitting. So in addition to trying to figure out the routing, I'm also trying to figure out how the hell to make this connection with the aluminum tube (which i'd like now to get rid of, except for maybe a foot of it).

Anyway, on the routing front, I have manual trim, which has pretty much used up the whole in the main spar near the center and the hole on the left side is full because I ran some RG-400 through there for the transponder antenna, which is under my seat.

I SHOULD have stuck the transponder antenna up by the firewall, but it's too late now.

I also considered running it right up the sidewall by the pilot (and covering it with upholstery) but there's the rudder cable in the way.

RVNewsletter · Post by **RVNewsletter** » Wed May 19, 2010 9:58 am

The connection problem was easy to fix, just swap out a -3 nipple for a -4 nipple. For some stupid reason, I figured the end that screws into the pipe fitting would be a different size.

Would that the routing now to the instrument panel were as easy a fix.

Bob Barrett · Post by **Bob Barrett** » Wed May 19, 2010 7:42 pm

On my pitot tube I just used some rubber tubing and safety wired it over the aluminum tubing were the tubing entered the fuselage from the left wing. I used the blue plastic tubing that came with my angle of attack from Safe Air and/or Dynon. The couplings were provided.

RVNewsletter · Post by **RVNewsletter** » Tue May 25, 2010 7:23 am

I know you're breathlessly awaiting the results but I ended up just pulling the old aluminum tube out and throwing it away. Also made a 7/16" hole in the wing spar to route it forward. Now I'm realizing I should've made it bigger because I think I want to put in an AOA.

I'm at the stage of the build -- the end -- where I want to remake stuff I made 9 years ago to make it better.