Has anyone placed their static ports on the sides of the boot cowl? I looked for a reference in AC 43-13 but couldn't find anything specific. Advantages-mounting on a firm surface and shorter tube runs. Thoughts?
Has anyone placed their static ports on the sides of the boot cowl? I looked for a reference in AC 43-13 but couldn't find anything specific. Advantages-mounting on a firm surface and shorter tube runs. Thoughts?
I plan to vent static behind the panel. These are not sealed up cabins, so why bother with an external port?
I too placed the static ports behind the panel.
Ackselle
Kitfox IV 1200 Classic C-GIKV
29" Airstreaks, 11" Matco Tailwheel
ROTAX 912, Hoffman HO-V352F CS Prop
I also opted for the behind the panel porting. Works very well and is very simple. I put a tee back there with a short stub of tubing with a little auto fuel filter over it to keep dirt and what ever out of the static system.
When I bought my first Kitfox, a model 3, I did the same thing to it after the static port came unglued from the side of the fuselage. This was easier than trying to reattach in the original location and worked better.
DesertFox4
Admin.
7 Super Sport912 ULS Tri-gear
Not me, I put the static in the back of the fuse.
And after some stories in this very forum about Side-slips and loosing altitude indication, I put another one on the other side of the fuse.
Never gave me problems since then (7 hours :-))
I am planning on experimenting with this as mine are behind the panel but my airspeed is also off by 3-5 mph (to high). Have the kit to do as HansLab did, won't get to it till spring though.
Dorsal ~~^~~
Series 7 - Tri-Gear
912 ULS Warp Drive
I think the boot cowl would be the best place of any, but my Highlander has one there and it too was off just like the one on the rear fuselage side of my Kitfox.
Maybe if you used two static ports on the boot cowl, one on either side of the fuselage and teed them together it would be better?
But honestly, under the panel is easiest in my opinion. And unless your Kitfox has an airtight cabin (is that even possible?), I can't imagine finding an area that is more pressure neutral than under the panel.
From an engineering standpoint the boot cowl in general is a terrible place to locate static ports. You might be able to find a specific location there on your bird that is acceptable, but being close to the propeller & in it's slipstream is bad. Because of the swirling or rotating/disturbed air, the boundary layer can be compromised. If air is impinging on the port, pressurization or de-pressurization can occur. What you want is static ambient pressure - no suckin' or blowin'. It's the same issue in the cockpit... air rushing past openings on the fuselage can cause increased or decreased cabin pressure. I know that location works fine for some, but it can be a crap-shoot. If you're going to put it on the fuselage, the rear sides are usually the best, as proven by multiple factory built designs for many decades. One on both sides, teed together will help eliminate the issue of inaccurate pressure due to slips.
So, engineering aside, whatever works for you on your particular airplane is all that matters, I guess, so... never mind.
John Evens
Arvada, CO
Kitfox SS7 N27JE
EAA Lifetime
Chap. 43 honorary Lifetime
Putting it on the side of the cowling would mean it would need to be disconnected every time you removed the cowl to service the engine.
So that was disappointing, I spent a couple of hours and moved the Static port to the recommended location along the side of the fuselage. My airspeed went from indicating 3-5 mph too high to 7-8 too low
On the bright side it turns out adding an inspection port after the fact (in a location I can not reach from inside the plane) was fairly easy.
Dorsal ~~^~~
Series 7 - Tri-Gear
912 ULS Warp Drive