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Old August 18th 11, 11:05 AM posted to rec.aviation.soaring
GC[_2_]
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Default Flaps VS Airbrakes/Spoilers

On 18/08/2011 08:40, Eric Greenwell wrote:
On 8/17/2011 2:50 PM, GC wrote:
On 18/08/2011 00:44, Eric Greenwell wrote:

Not only do they look like it, they are, in fact, bent down a bit. I saw
that on my ASW 20 C, and I see it on my ASH 26 E.


But that's not really due to the flaps. The clever Schleicher mixer
design raises the ailerons as the flaps move to landing. ASH-25s show it
best of all.


My inner engineer must quibble with this, though I agree it is a clever
mixer system. On my 26 E, it even puts a little washout (ailerons up
slightly) in the thermalling flap position to improve control at low
circling speeds.

For the landing, it's the difference in control surface deflection that
does it: the high lift coefficient flap section requires a very low
angle of attack to produce the proper lift, so low that the low lift
coefficient aileron section is producing negative lift.


My inner engineer will pay that.

GC