Drain holes under Schleicher seatpans

I suppoose it depends on what you take as a baseline to measure
improvement from. *

What I believe Schleicher was trying to improve was the shrinkage
problem, by allowing the operator to remove the root rib panels
between long intervals of unballasted flight, as well as the ballast
capacity, needed to get the wing loading up in 18M configuration.

The only problems with the 28 are the rather long dump time even with
the improved double vents of the later models, and the fact that water
drains from the vents if the tips are low. *

The 28 has no shrinkage issues like the 27?

Does the 29 fix both those issues?

Nope. Still drains from the tip, and a dump of 28 gallons required
just under 3 minutes at 75 knots indicated. A full ballast dump would
require between 5 and 6.

I wonder if a one-way flap valve would work in those wingtip vents ...
allow air in but not water out?

I don't know why they didn't put a decent size vent at the root which
I think is what the LS-8 has.

Good question.

-ted

On Jan 12, 9:48*am, Tuno wrote:

The 28 has no shrinkage issues like the 27?

Yes it has the same problem but not as bad as the 27. I have never
been convinced it has anything to do with water ballast. It would be
nice to hear from someone that has never ballasted their 27 or 28.

Nope. Still drains from the tip, and a dump of 28 gallons required
just under 3 minutes at 75 knots indicated. A full ballast dump would
require between 5 and 6.

I timed mine at over 8 minutes for 9psf loading (about 30 gals) but
that was on fast final glide. I think it dumps a bit faster flying
slowly.

Andy

I have never been convinced it has anything to do with water ballast. *

Anecdotal evidence ... I've heard from Schleicher owners who do not
have shrinkage, but either don't use ballast or use bags instead of
tanks, and I've seen the shrinkage on several 27s that did use ballast
regularly.

I'd like to hear from an owner with shrinkage who didn't use ballast,
or an owner (in the southwest USA) who used wing tank ballast
regularly for more than a few years and has seen no shrinkage.

Reading the flight and maintenance manuals for my 29, the factory
seems to be rather adamant about keeping the wings dry inside. Who am
I to argue with the book ...

..02NO

On Jan 12, 11:03�am, Tuno wrote:
I have never been convinced it has anything to do with water ballast. �

Anecdotal evidence ... I've heard from Schleicher owners who do not
have shrinkage, but either don't use ballast or use bags instead of
tanks, and I've seen the shrinkage on several 27s that did use ballast
regularly.

I'd like to hear from an owner with shrinkage who didn't use ballast,
or an owner (in the southwest USA) who used wing tank ballast
regularly for more than a few years and has seen no shrinkage.

Reading the flight and maintenance manuals for my 29, the factory
seems to be rather adamant about keeping the wings dry inside. Who am
I to argue with the book ...

.02NO

Experienced 27/28 owners do the Nixon/Murray mod which lowers the dump
time to less than 4 minutes. I did it to my 27 and its an easy mod.,
takes a few hours and less than 200 bucks.

My 29 dumps from full tanks to empty in 3 1/2 minutes. Thats been
timed several times.
I don't have shrinkage and mine is the second oldest in the USA. I
will add I have a 2"wave gauge and do use it.

If you take a factory tour and become educated on how the wing is
constructed it would give you valueable insight. Worthless hearsay is
an avenue I wish not to pursue. I have been to the factory, watched
the construction methods and spent quite some time with AS trained
folks.

Trying to compare one model with another is like comparing apples to
oranges. A wise monkey will be happy with either the apple or orange,
so as I'll go climb my tree and enjoy eatting my banana.

On Jan 12, 12:21*pm, wrote:
Experienced 27/28 owners do the Nixon/Murray mod which lowers the dump
time to less than 4 minutes. I did it to my 27 and its an easy mod.,
takes a few hours and less than 200 bucks.

I had discussed the modified dump valves with LX, and seen how it was
done, but did not make the modification because because I do no ridge
flying.

If you take a factory tour and become educated on how the wing is
constructed *it would give you valueable insight. Worthless hearsay is
an avenue I wish not to pursue. I have been to the factory, watched
the construction methods and spent quite some time with AS trained
folks.

Given all that insight do you believe that the wing profile change
seen in the ASW 27, and to a lesser extent in the ASW 28, is caused
by residual moisture from ballast?


Andy

On Jan 12, 12:44�pm, Andy wrote:
On Jan 12, 12:21�pm, wrote:

Experienced 27/28 owners do the Nixon/Murray mod which lowers the dump
time to less than 4 minutes. I did it to my 27 and its an easy mod.,
takes a few hours and less than 200 bucks.

I had discussed the modified dump valves with LX, and seen how it was
done, but did not make the modification because because I do no ridge
flying.

If you take a factory tour and become educated on how the wing is
constructed �it would give you valueable insight. Worthless hearsay is
an avenue I wish not to pursue. I have been to the factory, watched
the construction methods and spent quite some time with AS trained
folks.

Given all that insight do you believe that the wing profile change
seen in the ASW 27, and to a lesser extent in the ASW 28, �is caused
by residual moisture from ballast?

Andy

Has nothing to due with carrying water ballast.

Simply basic answer...curing cycle. Whats used today, is much better
than what was used over years past. Other words, the goup, which is
used to glue it together, has gotten better. We humans are still
learning.

UV breaks down waxes/sealers which then allow moisture into the gel
coat pour. When moisture gets into the gel coat pour, expansion and
contraction occur due to temperature differences, then on a mirco
scale, "**** starts to happen". UV breaks down waxes/sealers alot
faster than most think. UV sun blockers we use have to be reapplied
quite frequently. Most waxes/sealers break down within 250 hrs of
direct tropical sunlight.

At this point, Ralph would say " And away we go".