Dave,

Just wanted to say that I have visited your site for the first time in
several years and I did want to express admiration for the amount of
work that you have put in and the amount of research that you have
gathered and placed online. There seem to be some papers on the
Flettner there? If my hasty assessment is correct, I look forward to
reading them. I don't know enough about the Flettner (or the Doblhoff
either).

I see many conclusions with which I disagree, and even some stated
facts that strike me as mistaken, but it has been a prodigious effort
on your part and deserves a salute on that basis.

An example of the thing that gets to me... Hiller couldn't compete
effectively? He beat some of the big guys. He sold a great number of
H-23s to the US military after beating competition including Bell for
the contracts, over a period of 15+ years. I bet the sales guys from
Bell and Hughes felt pretty lousy when those contracts were awarded. On
top of that, Hiller sold several hundred civilian 360s. Plus a couple
hundred 1100s. (The H-23 is a great machine, and still well supported,
unlike its contemporary the Bell 47).

Incidentally, Stanley Hiller started with coaxials (I know, not the
same thing as intermeshing rotors at all). But it's interesting that a
guy who pioneered that design abandoned it and went to his own version
of the penny-farthing design. Do you know why? (I'm not being
facetious, I don't know and thought you might).

I would suggest that building and selling rotorcraft is a business, and
that designs and companies succeed and fail more frequently for
business that technical reasons, IMHO. The Beta/VHS or Mac/PC model, as
it were.

--
cheers

-=K=-

Rule #1: Don't hit anything big.