----------------------much snipping-------------

If I'm not mistaken, Hughes once built some kinda
giant tip-thrust powered test-freak that had a rotor speed of about 16
rpm. I've seen the videos, but I can't recall the name.


Fairchild-Hiller once built something like that, supposedly with ram jets in
the tips, and Hughes may have as well; although I am fairly sure that the
rotor speed was within the normal range for helicopters.

There was also a propane fueled pulse jet powered single blade helicopter of
the strap-onto-the-pilot variety several years ago. ( I even had a "blurb"
about it--and a related APU for gliders--which may still be buried among
other books and catalogs.) Although I don't know if it ever flew out of
tether...

Peter

P.S.: As to the original post: the pilot shops at most airports have
passable texts to introduce the theory of helicopters, and a lot of
accomplished helicopter pilots and mechanics used to hang around on
"rec.aviation.rotorcraft: so that lurking over there could pay dividends...