Fueselage Static Port Routing / Pathing

[lakespookie]

I know a few of you have done the static port in the fueselage and i think i am going to do something similar i ordered a pair of bulkhead ports from spruce, I am not using the stock probe because i will be installing a gap 26 near that location and access panel. That being said I figured i would ask those of you that have done the fueselage static port how you routed the lines and what you used to secure the lines in said path.

For reference i am thinking of doing the dual ports one on each side of the fueselage with a T and routing that up and down the back side of the baggage compartment to prevent moisture from staying in the lines. No hurry on the answer as i have a bit before i get to that part of the kit but it would be nice to have a plan before hand.

[GordonTurner]

Without actually being helpful I will point out that the exact location of those ports on the sides of the fuselage is critical. Ideally the fuselage pressure needs to be mapped to find a neutral area.

That being said, I have done the exact same thing you are proposing, and just picked the spots for the static ports by TLAR. Once I start flying I will have to see how accurate the static readings (altitude) are at various airspeeds and possibly try other locations. To that end I am plumbing with plenty of extra.

From the static ports, the lines should go UP to the top of the fuselage where they will join and go forward. These lines need to drain any moisture.

Nice system this Garmin. Can’t wait to see it in action. As regards your IFR flying, build it for the mission you want. I’m including the heated 206. Then operate very very carefully and expand your operation as you feel fit. The plane doesn’t know it isn’t supposed to be in that cloud. It will do fine as long as you are careful and maintain your skills.

Best, Gordon

[peter anson]

Gordon's advice all sounds good. My own experience with the standard Sonex static port position is that it results in slightly inflated air speed figures, about 5% high is my recollection. I'd be interested to hear other's experience on this.

Peter

[Kai]

Agreed,

The fairly conventional pitot/static probe outlined in the plans is not very convincing. But- to be fair- the slower you go, the more accurate the ASI becomes.

I flew around with this setup for 10 years. When renewed testing after an engine change became a necessity, initial results were astonishing: the thing was now on steroids! So much, in fact, that I became suspicious.

Then I recalled a comment from Kerry: when testing the factory prototypes they often just terminated the static ports from the instruments between fueltank and panel.

I thought it might be worth a try- the subsequent comparison flight with a C172 at 100 kts IAS revealed near identical values. The same result when comparing with an overpowered RV4 and my Legacy at wot.

I have not come around to change this setup yet.

Thx

[Scott Todd]

I have consulted on lots of homebuilts, especially Kitfoxes. I always recommend venting the static port behind the panel. For slow, leaky cockpits, this is the closest to true static pressure you can get. There is very little air movement back there and its not affected by climb angle, slipping, etc. For a fast airplane or one where the cockpit is sealed pretty good such as in composite airplanes, its can start to show slight errors. I probably wouldn't recommend it for a 200 mph airplane but certainly for anything closer to 100 mph. For a modern Sonex with an EFIS, its pretty easy to verify its accuracy or even tweak the setting on the EFIS if necessary.

[builderflyer]

Gordon's advice all sounds good. My own experience with the standard Sonex static port position is that it results in slightly inflated air speed figures, about 5% high is my recollection. I'd be interested to hear other's experience on this.

Peter

Using the plans-built pitot-static system on my Sonex, the IAS were 10% high until I added a ring collar behind the static ports to raise the pressure a tad. The CAS, subsequently, are within 1 or 2 mph from 90 to 190 mph. Since my plane now has a Dynon Skyview setup with the ADAHRS located behind the baggage department, I'd like to move the static ports to the sides of the fuselage but I'm still waiting for one of you fellows with a camera installation to do some tuft testing to help find the optimum location for the ports. I'm too cheap to buy a camera just for that purpose. The one time I tried the "behind the panel" location for static pressure, the introduced error was too significant to be useful.

Art,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,Jabiru 3300 #261

[XenosN42]

For a modern Sonex with an EFIS, its pretty easy to verify its accuracy or even tweak the setting on the EFIS if necessary.

The Flight Data Viewer contains a tool to help with static port calibration. https://jasflyer.com/FAQ/AN4.aspx

[Bryan Cotton]

The one time I tried the "behind the panel" location for static pressure, the introduced error was too significant to be useful.
Art,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,Jabiru 3300 #261

Art, I went with behind the panel based on Kip's success with that location. Cessna released a service bulletin for the C120/140 that had you disconnect the wing mounted static port and vent it to the cabin instead - so it can be good. Of course your personal evidence says it can be bad as well. Static port locations are a black art.

[peter anson]

Using the plans-built pitot-static system on my Sonex, the IAS were 10% high until I added a ring collar behind the static ports to raise the pressure a tad.
Art,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,Jabiru 3300 #261"

Can you describe the "ring collar" Art? Is it just a small tight fitting O ring or something a bit fancier?

Peter

[gammaxy]

Ben's airspeed indicator was reading high in a stall and it seems he traced it back to a loose static line at the altimeter: viewtopic.php?f=21&t=6596#p50047

As it sounds others have had good experiences with venting behind the panel, it would be interesting if he comes back to confirm whether he solved the issue.

I installed mine as shown in the plans and haven't noticed any errors in level flight, but my static pressure does seem to be affected when I pull positive or negative G's. If I pull up into a loop, the altimeter will initially show a dive. Interestingly, it seems that the error works out that the ASI indicates essentially the same stall speed for level and accelerated stalls.