Why a static port?

Seems like total crap, put it in english would ya
Wayne

It most certainly does!
since nR=(P1V1)/T1=(P2V2)/T2
Where P1, V1, T1 can be the exterior conditions, and
where P2, V2, T2 are the interior conditions
it shows the relationships between the variables
changing any one variable, alters the other five

It is pretty much crap. The law itself (PV=nRT) is certainly
not crap. That's the ideal gas law. P is the pressure, V
is the volume, n is the amount of gas (usually in moles),
R is the ideal gas constant, and T is the Temperature.

So if you change the temperature, pressure, or volume of a fixed
amount of gas by a known amount, holding one of those parameters
constant you can compute how much the other quantity changes.
Works very well at low pressures when the behavior of a gas
approximates the ideal gas model.

However what is the volume of the gas outside the airplane?
(Not to mention that the gas inside the airplane is not the
same gas as the stuff outside the airplane).
I think you can see that this equation doesn't help here.

~Paul

Yep, still seems like crap to me, but thanks to you both that answered
anyway. I mean I see that if you open the vents and give the air nowhere to
go, the pressure will increase, I can feel that with my ears. I also see
that with the vents closed, the shape and there the air escapes could make a
vacuum too. For those reasons, I see that the outside of the plane is a much
more stable place to get the static reference. But all that fancy eqation is
to me is crap. To me you make a system, test it to see if it is close to
what is actually going on, and forget about it. The engineers can worry
about all the details, not the airplane owners (this is the owners newsgroup
I hope).

I thought he had a typo and was trying to type pervert ;-)

Your original post included the text below. If you meant not to pipe the
static outside, then you would have the error introduced by each particular
aircraft, that would take calibration to get accuracy and would still change
when the cabin pressure changed for many reasons. Is that what you meant?

Wayne

Without the static ports, we could get rid of all that silly
tubing and just leave the static port connection to the instruments
open to the air. (Of course there is no getting around needing
a tube for the pitot port.)



It is pretty much crap. The law itself (PV=nRT) is certainly
snip
same gas as the stuff outside the airplane).
I think you can see that this equation doesn't help here.

~Paul