"ET" wrote in message
...
wrote in
ups.com:

Actually, the CAFE numbers come out a little better than what Van
states as the performance figures for the RV-6. And the stall speeds
that Van posts are pretty much what J. Roncz predicts in his
spreadsheets, even though Van's are a bit better. But then again
Van's planes may be operating at a slightly higher CL than what Roncz
uses. Which leads me to believe that the spreadsheets are quite
accurate.

This is why I'm having a hard time believing that the Sonex aircraft
meet the LSA rules as written. Even at the lightest version of their
aircraft ( Jabiru 2200 power and flown solo and no fuel ) the plane
would have a hard time meeting the stall requirements of LSA which
require max gross wt. figures with a 51 mph stall speed.

And my intention is to fully understand the LSA rules, not "down" the
Sonex aircraft or the people behind it. I believe the Sonex and its
people to be top notch, as do many others, evidenced by how many are
flying and continue to be built. They are reasonally priced,
economical to operate and good "all around" performers for their
power. And from what I have seen, several of the other "popular"
LSA's would have a hard time meeting the LSA specs. as I see them
written.

Neal



Which part of my post that indicated the fuselage of the Sonex is a
lifting body confused you??? Steve Wittman is said to have won a bet or
two with the same issue on the Tailwind. I have not done it, but plug
the same numbers in for the Tailwind and see what pops out.

--
-- ET :-)

"A common mistake people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools."---- Douglas Adams

Quite true. Lifting bodies can generate a lot of lift, and airfoils vary
wildly in their maximum coeficient. Also, there is nothing in the LSA
rules, or any others that I can think of, to require that an aircraft be
able to maintain level flight at stall speed--so drag coefficient is not a
factor.

Peter