Schleicher pneumatic tube plumbing question

I've dispatched this question to the dealer and factory, but need to
troule-shoot quick so trolling here. I have a 2008 Schleicher ASG29
with confused instruments following some repair work.

My question is, in its factory configuration, are the three lines from
the multi-probe free of joints, splices or connectors all the way to
the instrument panel? (I'm sure this is the case for the TE and Ptot
lines, it's the static I'm curious about.)

I'm a little unclear about the total Pstatic implementation, with both
an E-Systems multi-probe and what appear to be static ports on the
fuselage a meter north of the rudder. Are the two combined?

~ted/2NO

ps the symptoms a varios appear to operate without TE compensation
and the ASI is not correct, mostly floating around 40-50% of what it
should be reading. Altitude readings correct on altimeter, 302 and
LX7007. The LX's vario's average always read 0.0, even when climbing
it what felt like very strong wave.

Ted,

I haven't looked at an ASG29, but I'm pretty sure, as delivered, the
fuselage static ports go to the ASI and Altimeter only. The nose Pitot goes
to the ASI only.

The tail probe/s, pitot, static, TE, are direct the back of the panel.

bumper
zz
"Tuno" wrote in message
...
I've dispatched this question to the dealer and factory, but need to
troule-shoot quick so trolling here. I have a 2008 Schleicher ASG29
with confused instruments following some repair work.

My question is, in its factory configuration, are the three lines from
the multi-probe free of joints, splices or connectors all the way to
the instrument panel? (I'm sure this is the case for the TE and Ptot
lines, it's the static I'm curious about.)

I'm a little unclear about the total Pstatic implementation, with both
an E-Systems multi-probe and what appear to be static ports on the
fuselage a meter north of the rudder. Are the two combined?

~ted/2NO

ps the symptoms a varios appear to operate without TE compensation
and the ASI is not correct, mostly floating around 40-50% of what it
should be reading. Altitude readings correct on altimeter, 302 and
LX7007. The LX's vario's average always read 0.0, even when climbing
it what felt like very strong wave.

On Dec 6, 5:48�pm, Tuno wrote:
I've dispatched this question to the dealer and factory, but need to
troule-shoot quick so trolling here. I have a 2008 Schleicher ASG29
with confused instruments following some repair work.

My question is, in its factory configuration, are the three lines from
the multi-probe free of joints, splices or connectors all the way to
the instrument panel? (I'm sure this is the case for the TE and Ptot
lines, it's the static I'm curious about.)

I'm a little unclear about the total Pstatic implementation, with both
an E-Systems multi-probe and what appear to be static ports on the
fuselage a meter north of the rudder. Are the two combined?

~ted/2NO

ps the symptoms a varios appear to operate without TE compensation
and the ASI is not correct, mostly floating around 40-50% of what it
should be reading. Altitude readings correct on altimeter, 302 and
LX7007. The LX's vario's average always read 0.0, even when climbing
it what felt like very strong wave.

Have you looked at the owners Maintenance Manual? Page 2-36 will give
you your answers.

Thanks Tom! A little embarrassed about not checking that first. (Got
disappointed the last two times.)

Very nice hit on this one.

2NO

On Dec 6, 6:08�pm, Tuno wrote:
Thanks Tom! A little embarrassed about not checking that first. (Got
disappointed the last two times.)

Very nice hit on this one.

2NO

Trust me, I have been where your at before....

On Dec 6, 6:48*pm, Tuno wrote:
I've dispatched this question to the dealer and factory, but need to
troule-shoot quick so trolling here. I have a 2008 Schleicher ASG29
with confused instruments following some repair work.

My question is, in its factory configuration, are the three lines from
the multi-probe free of joints, splices or connectors all the way to
the instrument panel? (I'm sure this is the case for the TE and Ptot
lines, it's the static I'm curious about.)

I'm a little unclear about the total Pstatic implementation, with both
an E-Systems multi-probe and what appear to be static ports on the
fuselage a meter north of the rudder. Are the two combined?

~ted/2NO

ps the symptoms a varios appear to operate without TE compensation
and the ASI is not correct, mostly floating around 40-50% of what it
should be reading. Altitude readings correct on altimeter, 302 and
LX7007. The LX's vario's average always read 0.0, even when climbing
it what felt like very strong wave.

The front-hinged canopy on your ASG-29 is probably the same as on my
ASW-28. When the canopy opens, the tubing has to follow it. When the
canopy closes, there is a loop of tubing that can kink. I had
problems with my varios such as yours where they did not appear to TE
compensated. While looking at the tubing carefully with the canopy
closed I found a loop of tubing that would kink closed with a crimp.
I cut out that segment and spliced it together with a connector and
then protected it from bending with an external splint/stiffener such
as might be used to keep wires together in a loom obtained at the
hardware store. That fixed the problem. It was impossible to see
with the canopy open!

Tom Nau

On Dec 6, 9:21*pm, Tom Nau wrote:
On Dec 6, 6:48*pm, Tuno wrote:
I've dispatched this question to the dealer and factory, but need to
troule-shoot quick so trolling here. I have a 2008 Schleicher ASG29
with confused instruments following some repair work.

My question is, in its factory configuration, are the three lines from
the multi-probe free of joints, splices or connectors all the way to
the instrument panel? (I'm sure this is the case for the TE and Ptot
lines, it's the static I'm curious about.)

I'm a little unclear about the total Pstatic implementation, with both
an E-Systems multi-probe and what appear to be static ports on the
fuselage a meter north of the rudder. Are the two combined?

~ted/2NO

ps the symptoms a varios appear to operate without TE compensation
and the ASI is not correct, mostly floating around 40-50% of what it
should be reading. Altitude readings correct on altimeter, 302 and
LX7007. The LX's vario's average always read 0.0, even when climbing
it what felt like very strong wave.

The front-hinged canopy on your ASG-29 is probably the same as on my
ASW-28. *When the canopy opens, the tubing has to follow it. *When the
canopy closes, there is a loop of tubing that can kink. *I had
problems with my varios such as yours where they did not appear to TE
compensated. *While looking at the tubing carefully with the canopy
closed I found a loop of tubing that would kink closed with a crimp.
I cut out that segment and spliced it together with a connector and
then protected it from bending with an external splint/stiffener such
as might be used to keep wires together in a loom obtained at the
hardware store. *That fixed the problem. *It was impossible to see
with the canopy open!

Tom Nau

Right, I've had a number of calls where it turned out the pitot
tube was getting kinked closing the canopy, causing some
bizarre behavior including reduced ASI reading and sometimes
non-zero ASI after roll-out...

After you sort that, do a really good leak check !

Hope that helps,
Best Regards, Dave "YO electric"

A small fly in the ointment ... the repair manual indicates
transparent lines from both static sources. My glider has a blue and a
clear.

I'm fairly certain the blue comes from the fuse ports (which will be
easy enough to test) because it goes to the ASI and ALT, but when I
added the B40 and 302 after delivery I connected their static inlets
to that line. The LX alone has the line that (I assume) goes to the
multi-probe. If nothing else, to match the diagram in the manual, I
need to connect the varios to the multi-probe source, and the ASI and
ALT to the fuse source.

2NO

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

On Dec 6, 7:21*pm, Tom Nau wrote:
On Dec 6, 6:48*pm, Tuno wrote:

The front-hinged canopy on your ASG-29 is probably the same as on my
ASW-28. *When the canopy opens, the tubing has to follow it. *When the
canopy closes, there is a loop of tubing that can kink.

I had exactly the same problem with my 28. The first clue was that
the vario reading changed as the canopy was lowered. I was able to
fix the problem without cutting the lines by splinting them with
another section of tube cut along its length and fixed to the outside
of the kinked tube with cable ties.

Andy