Nice input., Dave. The Vintokryl is a good alternative, and it compares
quite nicely with the helicopter. The payload was 36,000 lbs and the
horsepower was about right (13,000 HP) so it lays on the line with a single
rotor helicopter, and far above a tilt rotor. Dr. Mikheyev gave a paper at
a conference that I was at and espoused that configuration. I will dig up
some details (maybe email Dr. Mikheyev) and post the comparison.

I think that payload was done with a rolling takeoff, as the gross weight
was eyewatering, and the hover performance was much poorer than a single
rotor helo (wing drag costs about 10% of total payload, but the wing adds
about 20 knots of cruise speed). The program was cancelled, reportedly
because of the aeroelastic problems between the rotors and wing. That is
also the reason why the early tilt rotors were not successful, and why the
V22 is a testament to the dynamic analysis technologies designers have
today.

Note that both the KA-22 and the CH-53E have the same horsepower as a V22,
but carry twice as much payload as the tilt rotor, even though the V22 has a
much more efficvient structural design, due to the fact that it was designed
40 years later. If a helo were designed with the same tools, the V22's
payload would look even worse.

Nick


"Dave Jackson" wrote in message
news:IbHZe.556210$s54.151893@pd7tw2no...
Nick,

Would it be fair to toss a third rotor configuration in to the
competition?

How about the Side-by-Side Kamov KA-22 "Vintokryl:

http://www.vstol.org/wheel/VSTOLWheel/KamovKa-22.htm

~ Speed of 192 knots [record]

~ Payload of 36,343 lbs [record]

~ Gross weight of 65,036 lbs

This is a 44-year-old helicopter. Just think of what could be done with
today's engines and composite materials.

I think that it's a slam-dunk for the Vintokryl.

Dave



"Nick Lappos" wrote in message
...
Just to keep the juices flowing, and get this newsgroup buzzing again,
try this:

http://webpages.charter.net/nlappos/...comparison.pdf