Static Port Location
Posted:
Thu Jun 16, 2016 5:20 pmby 8pointroll
Looking for some input on the best location for a static port on a tri gear Sonex. Thanks for your help. Stuart s/n 1106 most everything done but the wiring.
Re: Static Port Location
Posted:
Thu Jun 16, 2016 8:07 pmby fastj22
8pointroll wrote:Looking for some input on the best location for a static port on a tri gear Sonex. Thanks for your help. Stuart s/n 1106 most everything done but the wiring.
Mine is per the plans, right under the pitot tube.
Re: Static Port Location
Posted:
Thu Jun 16, 2016 8:34 pmby ScottM-Sonex1629
Same here, per the plans. Used he aircraft spruce supplied pitot static unit. Far as I can tell works great after 3 flights.
Re: Static Port Location
Posted:
Fri Jun 17, 2016 11:06 amby gammaxy
From my experience, it seems likely that someone could find a better location for the static port, but the plans location seems to work fine in the situations that most of us actually care about.
I'm unaware of anyone installing it somewhere other than the plans location.
It seems that locating it below the wing causes it to be influenced by the wing. The clearest way to demonstrate this is by pulling a couple G's from level flight while watching the altimeter--it's not hard to make the altimeter drop a hundred feet or so even though it is obvious you are accelerating upwards. If you have telemetry and you compare GPS altitude and the altimeter during the flare when landing, you'll see that the altimeter might drop 20 feet during the flare and then return to the correct altitude while slowing down on the runway. The other thing I've noticed is it seems the indicated airspeed of a stall is approximately the same in a 2G accelerated stall as a 1G stall (instead of ~40% more). I haven't really investigated all the details, but to me it seems that the airspeed indicator with the static port below the wing functions similarly to a lift reserve indicator.
The opposite of this is also true--unload a little on the stick in a climb and watch the vertical speed indicator increase by 100-200 fpm.
All of these examples are probably situations where you won't be paying much attention to the altimeter anyway. I've never noticed an error during cruise flight--at lower angles of attack the static port is less influenced by the wing.