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Old November 1st 07, 08:02 PM posted to rec.aviation.soaring
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Default Duo Dive-brakes ( Polar with spoilers extended?)

On Nov 1, 6:56 am, John Smith wrote:
Karl Striedieck wrote:
Is the 20 meter DG-1000 authorized for acro?


With 20m it's authorized for "basic" acro, which means Loops, Turns and
erect Spins. No rolls and no negative g.

With 18m it's authorized for full aerobatics.

If it is I'm curious about the
reason. Both ships were designed to meet JAR standards regarding strength
and dive brake performance.


Because the dive brakes are *not* of equal strenght. I've never compared
side by side, but the DG1000 definitely allows for a much more sloppy
approach. (Not that I would advocate sloppy flying!) I've read that you
compared them and think both are the same, I definitely don't share your
opinion.


Karl's side by side measurement is fascinating, but not what I would
expect.

I've got about 40-50 hours each in DG-1000S and Duo Discus and the
DG-1000S seems much more tolerant to sloppy handling on approach,
seems to wash off energy much more effectively with spoilers than the
Duo Discus and have less run out in ground effect. So why is this,
more effective drag (not lift spoiling) vs. speed in the DG-1000S? I
can't explain it but I definitely believe it is true. Couple this with
a more forgiving undercarriage and landings in the DG-1000S seem much
more tolerant of sloppiness than the Duo. This is not a slam against
the Duo, I like both gliders. I'll give the Duo the benefit in
handling, lighter aileron forces and very nice slow speed behavior as
it floats around a thermal (you can hear that inner wing rumble and
she just floats around).

BTW out of date now with the Duo-X but Karl did write up a comparison
of the Duo and DG-1000S in the June 2003 SSA Soaring magazine.

Since this topic is already all over the place - one thing I see in
the Duo-X collateral is Schemp Hirth still promote the light tail
weight and therefore easier ground handling (I'm sure aimed at the
DG-1000S). I wish they'd actually make the tail a little heavier to
help reduce those little tail raising surprises under brake - not that
I've ever done this but I've seen others do it :-) I suspect that is
a major change in moving the U/C more forward, but with adding the U/C
springs, and later stretched cockpit this is one thing I'd hoped they
would have tweaked as well. Anybody with Duo-X experience - is the
tail at least a little heavier?

Regards


Darryl