On Sun, 07 Feb 2016 07:52:54 +0000, Ommadawn wrote:

I enquired of the previous owner, who fitted the winglets mod about 5
years ago. He told me that although there didn't seem to be any tangible
performance gains, the handling was another issue. Apparently the
winglets improve very low speed handling, giving a noticeable
improvement in roll response just ahead of stall.

Fair comment. As far as I can tell winglets help at the low speed end of
the performance curve while undersurface turbulators and wing root
fairings improve the high speed performance.

The fairings would be nice because the airflow round the root of early
glass was often horrible and in some cases the wing planform made it even
worse. I thought about fitting fairings, but they are quite large and
would increase the root chord and/or the fuselage width (depending on how
you fit them and where you split them for wing removal), so it seemed
likely that using them would also mean a new trailer. Thats because mine
is a box trailer that was apparently designed on the principle of "pile
all the bits in as small an area as possible, draw a line around that
with a 50mm margin and that's the size of the trailer".


A link you may find interesting and that explains the above is:
http://www.betsybyars.com/guy/soarin.../72-modif.html

I was also looking for another Will Schueman article - the one about how
he diagnosed the low speed airflow problems on his modified ASW-12 and
how he fixed them, but I can't find a link to it. I have a local copy,
but wanted to quote the URL of an online copy. Frank, if nobody comes up
with a link but you'd like to see the article, e-mail me (address is at
end of this post and I'll send you a copy.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |