Static port

[GT280flyer]

I am working on my instruments, air speed, altimeter and vertical speed indicator and I am not sure how the static port should be plumbed. Should it be inside or should it be plumed to the outside of the aircraft? Any pointers?

[Mnflyer]

Hi, originally on the 1 2 3 and early 4's it was just inside the plane mine was a piece of clear tubing with small holes in it connect between the AS and Alt. this works but isn't the most accurate later on I think the factory offered a relocation static port kit, I did my own and it works good.

[Dorsal]

Mine is just open behind the IP (plug with a small hole), works well.

[DanB]

Many of us have the same set-up behind the panel with that fuel filter on the end of the tube. The Kitfox is not air tight so no need to toy with where slip stream is or isn't.

[GT280flyer]

Thanks guys, sounds like a simple solution to just vent them behind the panel. I should have thought of this Saturday at the fly in at Greene, there was a lot of kitfox knowledge there and some very nice kitfoxes.

[Slyfox]

I'm not trying to burst anybody's buble here, but I did a test on my static system. I have mine set up in the rear fuse where the factory says to put it. I took a valve and installed it so I can switch between inside and the rear fuse. Guess what? when I went to the inside, my indication went up almost 15mph. take that anyway you want, but I elected to put mine to the rear fuse because it reflected my ground speed on the gps more accurately.

[Dorsal]

Interesting, might have to try that. I suspect my IAS is high but not by more than a couple mph (based on ground speed and relative wind indication).

[Slyfox]

I used a three way ball valve, I think I got it from lockwood. I put it straight through and had the valve just under the panel. with the third way vented under the panel. there was a difference.

[DanB]

Interesting, might have to try that. I suspect my IAS is high but not by more than a couple mph (based on ground speed and relative wind indication).

That's what we have noticed...perhaps off by 1 or 2 MPH, but not much more. Frequently I would bring my GPS along on flights with others that have the port terminated behind the panel. our GPS speeds (as well as the round speed indicator) all matched within a couple mph. One of the things that we have done is watch the SI when we pop a door open. It certainly fluxuates the needle for a second but always comes back to rest in almost the same place.

Skyfox, that was an interesting experiment you set up being able to switch from inside to outside...even more interesting that it brought speeds into harmony with your GPS. My first thought would be that the port outside the plane would generate more of a varient. I built mine terminated behind the panel and look forward to getting into the air soon and do some testing as well. Good thread...any others do any similar tests?

[szicree]

I'm not trying to burst anybody's buble here, but I did a test on my static system. I have mine set up in the rear fuse where the factory says to put it. I took a valve and installed it so I can switch between inside and the rear fuse. Guess what? when I went to the inside, my indication went up almost 15mph.

If your static source is so out of whack as to cause a 15 mph error on a 100 mph airplane, then your altimeter is also off by something on the order of 7000 feet! (EDIT: Bad math; more like a few hundred feet)