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Old June 17th 07, 11:36 PM posted to rec.aviation.soaring
BlueCumulus[_2_]
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Posts: 37
Default Diana-2 - master-piece or flop?

Maciek wrote: If one of your ailerons pins out, or your flaps aren't
locked at their position - they will all deploy up. It is impossible that
the flaps are balanced that much ....


I do not agree with that.
It depends on the aerodynamic and kinematics design of the flap system.

The ASW27 does not show any tendency to change flap settings between
+2 and -1 which covers a speed range of 80-180km/h. The same I was
told to be the case for the ASW26. You can have the flaps in any inter-
mediate position and it will stay there. you can move the flaps to any
setting with two fingers (except -2 and Landing position).

As said before the prototypes of the Diana-2 have the wing position about
5cm (2") more tailward than this first "Serial Machine". Why the wing-
position was moved forward is not clear but confirmed. After such a
significant change I would rather call it a prototype as well. The handbook
as well did not show the new drawings and figures for the CG calculations.
The glider was month too late in production and delivered in a hurry after
just one test flight. This Diana-2 with production number 3 seems to be a
different plane in regards of flying behavior than the prototypes.
That's why I was wondering if anyone might have flown number 4.
__________________________________________________ ______

"Maciek" wrote in message
...

wrote:

Yeah, I'm curious too. I have an old Speed Astir, and had some trouble
with the flap lock becoming disengaged. It usually happened turning
base to final, and went from full positive to full negative in blink
of an eye. There is considerable force at all airspeeds and conditions
(except a negative "G" push) exerted on the flap control toward the
negative flap setting.


finally someone imaginative... There is a pressure difference betweene the
upper and the bottom surface of the wing, thanks to whitch our gliders can
fly (if there is enyone who doesn't know that...). If one of your ailerons
pins out, or your flaps aren't locked at their position - they will all
deploy up. It is impossible that the flaps are balanced that much, to
overcome the pressure difference and deploy to positive - especially in a
glider weighting 185 kg.

Mat