Steve wrote; "Abolishing the tail rotor? On a single rotor helicopter,
that'll be an interesting exercise"

Me writes; Agreed. Laterally located twin main rotors will be required.
Interestingly, Sikorsky proposed the following single rotor concept 2 years
ago, but its feasibility is questionable. ref.
http://www.UniCopter.com/1281.html
__________________

Steve wrote; "There are the multi rotor machines with counterrotating rotor
systems (tandem and coaxial) but if that were such a "big" advantage over
the conventional single main rotor / tail rotor configuration, I'd have
thought there'd be a LOT more of them out there by now."

Me writes; The tandem still lives, in fact, Boeing has proposed a
side-by-side for future heavy lift craft.
Unquestionably, the two best and most promising rotorcraft configurations at
the dawn of helicopter flight were the Side-by-side and the Intermeshing.
Then Germany lost the war. Additional reasons can be found at;
http://www.synchrolite.com/B280.html
________________

Steve wrote; "Active Twist rotor blades? That's an interesting concept. It's
not one I've heard of before. I've love to see the engineering specs on
them! :-)"

Me humbly submits; http://www.UniCopter.com/1101.html
________________

Steve wrote; "Larger, slower rotors? It's been done. It works Ok but you run
into the
problem of needing room to swing the blades."

Me apologizes. Should have said; ' significantly larger chord'.
________________

The tilt-rotor may shoulder its way into a market located between that of
the helicopter and that of the airplane. But, I strongly believe that a
potentially much larger market exists for helicopters, if the conceptual
focus can be redirected toward laterally located twin main rotor
configurations.

IMHO, Igor took helicopters in the wrong direction.


Dave J.





"Steve R." wrote in message
...

"Dave Jackson" wrote in message
news:ZxJXc.229824$J06.58978@pd7tw2no...
Me writes ~ When they brake away from the 60 year Western rotorcraft
mindset
and improve the L/D ratio, by;
- Abolishing the wasteful tail rotor,
- Providing Active Twist Blades, which can optimize the L/D ratio at
all
locations within the disk,
- Providing larger, slower rotors, plus a horizontal thruster.

Dave J


Abolishing the tail rotor? On a single rotor helicopter, that'll be an
interesting exercise. MD does have the Notar but it's still putting a
fair
amoung of power into pressurizing that tail boom. There is no free lunch.

There are the multi rotor machines with counterrotating rotor systems
(tandom and coaxial) but if that were such a "big" advantage over the
conventional single main rotor / tail rotor configuration, I'd have
thought
there'd be a LOT more of them out there by now.

Active Twist rotor bades? That's an interesting concept. It's not one
I've
heard of before. I've love to see the engineering specs on them! :-)

Larger, slower rotors? It's been done. It works Ok but you run into the
problem of needing room to swing the blades.

Horizontal pusher system? It's also been done. Now we're talking a
compound aircraft, or at least the beginnings of one, and an aircraft
that's
a LOT more complicated and expensive.

I think that the modern helicopter designs that are flying today, are
flying
because they've proven themselves to be amoung the best compromises that
can
be made between utility, cost, and function. They offer relatively good
speed, point to point, for short to medium distances (I'm thinking 500
miles), and can take of and land virtually any place there's enough room
to
swing the rotors in.

If you need faster, or greater distances, it's time to go fixed wing.

JMO!
Fly Safe,
Steve R.