pitot-static

[jacksel]

Thinking about the pitot and static requirements for my RV-7. I wanted my RV-6 to be IFR so I installed a heated pitot tube and the Van's static ports. I'm not unhappy with it but was wondering if there is a good combined pitot-static probe available for builders.

 

[Ironflight]

If you use something other than the Van's static ports, expect a LOT of flight testing to figure out how accurate they will be. Many flight test hours go into fine tuning static ports (pitot is really simple and hard to screw up, by comparison) - and many builders have flown many hours trying to get alternatives to work properly. Some succeed, and many more go back to the Van's design.

Off-hand, I don't recall hearing of any static port icing cases here on the forums in past years - I don't think it is very common to freeze up a port on the side of the fuselage.

 

[Walt]

Paul is absolutely correct, and while we're on the subject of static systems....

Please DO NOT push Nylo-Seal tubing over a 'T' fitting (like tying the static ports to the static line going forward), I have replaced so many of these in RV's I've lost count (the nylo tube will eventually split). Nylo-seal tubing is not made to be expanded and should only to be used with Nylo fittings or you can insert it into a 1/4" rubber line for a transition.

 

[Rupester]

Gretz heated Pitot and Vans static kit ...

... Work flawlessly in my 9A. I would do the same again.

 

[Daniel S.]

Walt.
Are the safeair1 static kits a problematic static kit?

 

[AirbusPilot]

Walt.
Are the safeair1 static kits a problematic static kit?

I have them installed on my 8, works flawlessly

 

[Walt]

Walt.
Are the safeair1 static kits a problematic static kit?

Not generally, use care when installing, cut the tubing square using a tube cutter made for static lines and use a tiny bit of silicone or dielectric grease on the tube. The metal fingers that retain the line can scratch the tubing so use care and try not to remove the lines unecessarily, if you see/feel any scratches on the end of the tubing cut it off to get a fresh surface.

 

[Noah]

I bought a project that already had a VERY expensive pitot-static tube as part of its inventory, so I used it, along with aft-fuse static ports from one popular vendor. I installed an alternate static toggle switch in the panel to be able to go back and forth between either static source. But the static source from the pitot-static tube always indicated different ALT/AS than the aft-fuse ports and, like Paul says, it did take HOURS of flight testing and data crunching to prove which of the two sources was more correct. Both had significant error, particularly at higher airspeeds. I tried putting rubber washers in front of the static ports on the pitot-static tube, but this did not help. I taped metal washers around the aft-fuse static ports, which helped but was ugly.

If I had the ability to move the pitot-static tube fore and aft there is a CHANCE that I might have found a location with acceptable static position error, but in looking at plots of the pressure distibution around the RV-7 airfoil (provided by Kevin Horton), even that is probably questionable.

In the end, I removed the toggle switch and disconnected the pitot-static tube static source, and replicated the Vans aft-fuse static port which yielded the best results I saw.

Take it from me, don't waste your time or money, the Vans static ports are DEFINITELY the way to go. As others have indicated in this forum, there is no known case of the stock static ports (both) having frozen over!

 

[Daniel S.]

Okay. Let me read between the lines here as an owner of a Gretz Heated Pitot tube & a safe air AOA plumbing kit with the intention of flying IFR and obviously having and alt static. I have no problem naming names & products What are they going to do refuse to take my money & take longer to ship my stuff? If it's ****, let's call it such

What I'm hearing is don't bother with the static ports or static line in the SA1 plumbing kit... Toss that in the trash & use the $19.00 van's static port kit & lines. If $20 bucks saves me a ton of head aches down the road, I'm all about spendiong it.

Now watch me get attacked. Before you attack me for running an AOA line... It's simply for options that may arrise during the build and for options down the road. I'm all about options.

 

[Roy Thoma]

I think jasksel was asking if there is an INTEGRATED pitot/static. There is a discussion (started by Paul) about using a Piper pitot/static blade at http://www.vansairforce.com/community/showthread.php?t=15219. Sounds like accurate slow airspeeds are not likely using the static port in the Piper blade.

One elegant solution using Van's pop rivet static port and supporting standard threaded 1/8 NPT fittings can be found on page 2 of the April 2005 CH105 newsletter at http://old.eaa105.org/Newsletter/Archives/2005/nl-200504.pdf More discussion about this solution included at http://forums.matronics.com/viewtopic.php?t=53008&highlight=static+rivet (Note that the link to the CH105 newsletter in the Matronics thread is not valid.)

The article shows making an adapter from a short piece of 1/2" aluminum round bar, drilling one end for the 1/8" rivet from Van's, drill and tap the other end for 1/8 NPT tube fitting. Pop rivet on the outside skin through the adapter on the inside of the skin, seal the adapter with proseal or ???. (Maybe someone can figure out how to copy the article and graphic from the newsletter.)

Daniel S -- I'm using components similar to those supplied in the SafeAir1 static kit with Van's pop rivet and adapters. Pitot/static, IFR checks have been painless so far. I used the Van's static kit in my Zodiac and it took some extra effort to get the system sealed.

Regards,

 

[jacksel]

Thank You for all the replies. I suppose since I've gotten 7 years of safe IFR flying out of my RV-6 (including a few inadvertent brushes with icing) , I should take that as a measure of proof-of-value for the basic Van's static system.

Jacksel