On Dec 6, 9:39*pm, Tuno wrote:
To answer my original question more accurately ... the manual
indicates the routing of the pressures, but does not describe the
implementation. As it happens, my 29 has small (maybe 2.5 or 3mm OD)
tubing from behind the instrument panel to under the seatpan, where
they step up to the larger size using the same kind of insert adapter
found on my O2 system controller.

The tubes going aft from there do not hold a vacuum (with the multi-
probe thoroughly sealed and inserted). I'm wondering (after talking to
CH) if the O-rings in the multi-probe's receiver were damaged ...

2NO

Thank goodness it's December Ted. If the multi-probe got tweaked in
the accident then it's possible that the fittings are AFU, but I'd be
surprised if it actually happened. You might try just plugging the
entire fitting with the probe removed to at least eliminate the
possibility of a tubing leak inside the fin/tailboom. You'll need to
clamp the other lines too. I am curious about the procedure for
replacing the O-rings as it seems nearly impossible from casual
inspection. Any experts out there on how to do it?

I too have had the infamous Schliecher canopy hinge tubing kink
problem on a hot day in Arizona. The symptom was a zero indication on
climb and a wildly inaccurate airspeed. I think that means a kinked
static line. I used GY's cure - a 4" piece of 1" OD tubing split down
the side and wrapped around all the pneumatic tubes where they bend as
the canopy closes. I secured the tube with tie-wraps. It's still there
and working today. Turns out the desert temperatures make the tubes
just enough softer that they fold under the pressure when you shut the
hatch. Fixing it in 112 degrees and full sun may have been the
sweatiest experience of my life. I am perplexed but the change in
tubing size you describe Ted. Do you have to up-gauge the tubes at the
panel to fit the barb connectors on your instruments?

Best of luck - glad 2NO's back home.

9B