Duo Dive-brakes ( Polar with spoilers extended?)

John,

The Duo Tom Knauff was flying when we did our full boards dive off was a
turbo version and thus heavier than a non-motorized ship. The DG-1000 I was
flying had heavier pilots, so the payload was about the same. We agreed to
this test before task opening on a day we had some extra time, because this
notion that the Duo had inferior speed brakes had been floating around for
some time and I wanted to see if it held any water. I joined up on Tom's
right wing, less than a span away, and he pushed over, deploying full brakes
and pushing the speed up to 80 knots. In this stabilized condition I had
full brakes deployed in the 1000 and did not fall back as one might expect
of a ship with better braking.

As to the matter of tail weights, wheel brakes and gear configuration there
are compromises with both approaches (long and short main gear). The old
Duo's short gear was simpler, lighter and farther aft. This makes for easier
ground handling but requires a nose wheel to handle max braking. The longer
gear of the Duo X and DG 1000 keeps the gear doors cleaner, but is more
likely to go on the nose if the brake is good.

Speaking of wheel brake effectiveness, I've spent more time adjusting,
bleeding, modifying and cursing the Duo brake than all other maintenance
matters combined. Maybe my expectations are too high after years of flawless
performance from Schleicher's Cleveland disc brake systems.

Karl Striedieck


"John Smith" wrote in message
...
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.