In article ,
(The Enlightenment) writes:
(WaltBJ) wrote in message . com...
For one, I can see that the cyclic pitch control system is not a
simple setup. In essence you need two sets of them, one for each
rotor, and with modern helicopters you need a double set of hydraulic
actuators, and some way to get the controls to the top rotor
actuators. So - $$$$$.
Walt BJ

Personaly, from an aestheic point of view, I prefer intermeshing
rotors. You avoid the complexities of a tail rotor and a coazial
linkage in a coaxial rotor.

They used to be quite common: Pieseki I think, Kaman and I think the
Germans had a little intermeshing Focker anti submarine unit in
service in WW2 circa 1943/44. What happened?

Flettner in Germany, Kellet adn Kaman in the U.S. Flettner lost the
War, The Kellets had problems with the blades hitting each other, but
a lot of Kamen K-225s (Navy HTK trainers) and K-600s Navy HUK-1s,
Marine HOK-1s, and AIr FOrce H-43s) wer made. With theeir low disk
loading, they could lift like anything, setting a bunch of altitude
records, and they were, from what I hear, almost too easy to fly. But
the bik killer was drag. While they could climb lije anything,
forward fligh has been described to me as "Pushing your Grandmother's
Turkey Platter sideways through a hurricane". They weren't fast, but
they sure were slow.

Kaman has had a bit of a resurgence with the K-Max, a dedicated crane
based on the K-600, and a few K-600s are used in the Pacific
Northwerst for logging. Just don't try to make one go faster than 100
mph.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster