pitot/static location

[Ray Toews]

My Jodel has the pitot and static under the wing, it is built
according to plans and is just two pieces of aluminum tubing taped
together which gets bumped fairly regularly, enough so that the
previous owner built a little stick jig to adjust the bend.
The front of the pitot is in line with the leading edge and when it
rains it drips onto the pitot and with cold and wet it froze so
I have been flying all winter with out an airspeed indicator, which is
no problem but annoying,,,, Soooooo,,,,

Why not install the pitot on the top of the rudder, the Jodel has a
full flying rudder so it would always be pointing into the relative
wind. Would this be enough of an advantage to offset the possible
disadvantage of having the pitot in the prop wash?

Also why not terminate the static line inside the wing, seems to me
the air inside the wing would be relatively static.

Your comments will be appreciated

Thanks

Ray Toews

[Ernest Christley]

Ray wrote:
hy not install the pitot on the top of the rudder, the Jodel has a
> full flying rudder so it would always be pointing into the relative
> wind. Would this be enough of an advantage to offset the possible
> disadvantage of having the pitot in the prop wash?

Run a seperate tube from your proposed location to a spot where you can
Y the connection into your pitot system and have both lines exposed in
the cockpit. Take the bird up and clamp off each in turn. If the
airspeed changes dramatically, it may not be a good idea. Try the test
in different flight regimes.

>
> Also why not terminate the static line inside the wing, seems to me
> the air inside the wing would be relatively static.
>

It may be static but not at ambient pressure. The wing creates a slight
vacuum behind it that will throw off your altitude measurements.


--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

[Unusual Attitude]

Ray Toews wrote:

>Why not install the pitot on the top of the rudder, the Jodel has a
>full flying rudder so it would always be pointing into the relative
>wind.

Pitot tubes remain reasonably accurate within the alphas and betas
encountered in normal flight. It is the static port that typically
suffers accuracy in beta (with attendant ASI errors). Best to mount
your pitot tube on the fixed airframe, not your full-flying rudder.

>Also why not terminate the static line inside the wing, seems to me
>the air inside the wing would be relatively static.

Bad idea. The pressure inside your wing could vary widely with both
airspeed and lift depending on where the various air gaps in your wing
are. Use a well-placed static port or combo pitot-static head.

-- UA