Static port requirements and criteria questions

Discussion in 'Instruments / Avionics / Electrical System' started by Captain_John, Dec 3, 2007.

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  1. Dec 3, 2007 #1

    Captain_John

    Captain_John

    Captain_John

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    Hey All,

    I am getting ready to install my static ports and the plans call for a pulled rivet through the skin, punch out the mandrel and install a plastic tube onto the shop head of the rivet. That is a bit ghetto fab for me, so I obtained two 8/32 panhead stainless screws that have been drilled through the center and the head has been ground smooth.

    Here is my question. How high should the lip be around the port? Should there even BE a lip?

    Some people have told me that they have had errors. The setups have been various and some are raised, others are flush while others have leading edge spoilers on them.

    What is the mystery in these little devils?

    What should I do to make them as accurate as possible?

    :ermm: CJ
     
  2. Dec 3, 2007 #2

    Jman

    Jman

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    Great Question. I hope someone with some insight answers this post.


    -----------------Side Bar-----------------------------------
    BTW CJ, got my practice kit today. Preview plans should be here in the next couple of days....My wife sent them together but the mail over here is spotty. Still loving the vids too. Thanks!
    -----------------End Side Bar-------------------------------
     
  3. Dec 3, 2007 #3
  4. Dec 3, 2007 #4

    wally

    wally

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    Well on all the static ports I have seen, they are flush with the skin. This is on Cessna/Piper and big planes. The big planes usually have a painted area and a notation to keep the holes clean and smooth. Sometimes they have to add a little bump or ramp just behind the opening depending on the local pressure in order to correct it. This is determined during flight testing.

    The big planes also have one on each side plumbed together to minimize errors.
    Wally
     
  5. Dec 3, 2007 #5

    Dana

    Dana

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    Gee, I like the rivet idea! Simple, light, and cheap.

    On my plane, I elected to make a pitot/static tube instead. I installed a larger concentric tube around my pitot tube, drilled four .040" holes equally spaced around it, and plumbed it to the static system.

    -Dana

    Roses are red,
    Violets are blue,
    I'm wasting much too much time on the internet,
    and probably, so are you.
     
  6. Dec 4, 2007 #6

    wally

    wally

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    I did kinda what Dana did only I made both the pitot and the static concentric tubes. I installed it in the lower left wing of my Pitts and seems to work pretty good at the few speeds I have checked w/ my GPS. If I were to make it again, I would rethink how the concentric tubes fit in the base block. I would probably have made them threaded instead slip fit with O-rings to seal. Anyway it works and only cost whatever a couple of short pieces of stainless tube costs. A friend at the machine shop had a spare chunk of aluminum and made the base block and the "pointy end thingy" (TM) to go on the forward end of it to match my sketch - for free.
    Wally
     
    Last edited: Dec 4, 2007
  7. Dec 4, 2007 #7

    Captain_John

    Captain_John

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    Hmmmm, well I suppose this is another one of those things where there is nuttin' to it but ta do it!

    I have read all the replies and googled up some information and now feel thoroughly competent so that I can over engineer my static system!

    :roll:

    I just realized that I want an ALTERNATE source from within the cabin as well! Several of the planes I fly have them and seeing that I will not have a VSI to smash, I am going to install a valve that I can open somewhere under the instrument panel to provide a secondary source.

    One site that was particularly helpful was this one:

    http://www.allstar.fiu.edu/aero/PSSI.htm

    I think that any of these static port methods are worthy of an attempt. I bet that they would probably be fairly accurate at providing a good "ambient" static source.

    I am going to use my drilled out stainless 8/32's and give it a try. If they show an unacceptable error, I will go to plan "B", whatever that may be.

    I do like the concentric tube idea! I would never have thought of it on my own. Good work guys!

    I now know more about static pressure than I did before this thread. Sometimes you just need to get your head inside the subject!

    :grin: CJ

    P.S. Jake, I am glad you are enjoying the Orndoff videos! You must be having trouble sleeping!

    :gig:
     

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