On Wed, 11 Sep 2019 15:56:27 -0700, Justin Couch wrote:

On Thursday, 12 September 2019 06:02:17 UTC+10, Senna Van den Bosch
wrote:

Still very interesting to see that happen. Are there any other gliders
that have this effect at higher speeds?

Yes. Particularly prevalent in the open class ships of the 80s & 90s
vintage. Watch an ASH 25 come screaming across the line at close to VNe.
Looks like a giant McDonalds sign!

Not quite the same, but its also fun to watch an Ash 25 on finals. See
how it changes from an elegantly curved wing to anhedral near the tips
when the brakes are opened.

More to the point: at thermalling speeds the centre of lift is around 33%
of the wing chord - pretty close to the spar position, but flying faster
moves the centre of lift rearward away from the spar, so this can twist
flexible glass wings toward a lower AOA. This will cause an increase in
washout at the wingtip.

Do 201 Standard Libelles do this? I can't recall ever looking at the
wings when flying fast in mine.


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Martin | martin at
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