Handling differences between the 15m vs 16.6 ASW-20CL?

On Jun 19, 2:33*pm, BruceGreeff wrote:
Indeed, the only extended 20 that I know of that really has a
performance increase is experimental. Owner / engineer took a big saw to
the wing and increased the span, while changing the airfoil and planform
and introducing polyhedral. Resulting weight distribution and control
responsiveness in 18m is conducive to performance that can / does match
things like JS1 in the hands of suitably skilled pilot. (Not over entire
flight envelope - which is where pilot skill counts)

Having less area outboard moved the wing centre of pressure inboard ,
substantially reducing the bending moment on the root - so it is
possible to increase the wingloading back to something sensible. Hence
it performs. Just increasing the span of the wrong airfoil by another
60cm or so is not going to improve anything.

This is particularly true with the ASW20 - because the wing is flexible,
and inclined to torsion. This results in the characteristic big vertical
tip displacement - not something you want to aggravate.

So - if yours is experimental, and you are brave, great things are
possible. Otherwise the standard 15m is a fine ship.

Bruce

On 2011/06/18 04:23 PM, JJ Sinclair wrote:





On Jun 16, 8:07 am, *wrote:
This past week I purchased an ASW-20CL. Wondered if anyone has any
thoughts on the handling qualities of the 2 configurations. The 15m
version is equiped with Nixon winglets. The previous owner never flew
with the extended tips so could not offer opinion or advice.

Thanks, Gary Adams

I have flown the 20b and the LS-3a with the 16.6 wing tip extensions
and IMHO neither did much to improve the glide and just made the roll
rate noticably slower. They may have just extended an airfoil that was
optimized for the 15 meter span which had been chosen to give a gentle
stall and didn't increase the performance when extended. I believe
only SH got it right when extending the wings with their Ventus and
Numbus. Schleicher figured it out and changed the last 10' in order to
get the desired results in both the 15 meter and 18 meter
configurations on the 29.
Just my observations& *opinions,
JJ

--
Bruce Greeff
T59D #1771 & Std Cirrus #57- Hide quoted text -

- Show quoted text -

Thanks JJ and Bruce,
The answer is "yes" it is experimental.....and "no", I'm not brave,
the 15m tips will do just fine with it's Nixon winglets!
Thanks,
Gary Adams
ASW-20CL #20791 GA2