Peter Seddon wrote:
This website gives quite an interesting history of Kamov who have been
making co-axials for many years
http://avia.russian.ee/vertigo/peopl...v/index_2.html and are the makers
of this latest one.

On this latest single place the lower swashplate is visible in some photos
and it looks like the pitch arms for the upper rotor go down the center of
the main shaft.

Regards Peter


"Stuart & Kathryn Fields" wrote in message
...

Very interesting. I can't see any pitch control linkage to the blades.
Don't read Russian, but do they say anything about autorotation?


I don't see any evidence of pitch links at all, unless they are
hydraulic, with rotating hydraulic joints, hydraulic tubes inside
the shafts, and very small actuators.

For autorotation, it could use engine torque actuated linkages to
adjust collective for autorotation. If engine torque goes to zero,
pitch goes to negative, pilot alarm is momentary negative gees and
imposed descent - forced autorotation on power loss. I suggested
such an idea several years ago on this forum. You don't think they
stole my idea? Or maybe they adjust pitch by moving the relative
position of three concentric rotating shafts up and down a half inch
or so? There might not be any cyclic control at all.

Why not?

Yaw control by differential rotor torque and tailfin in downwash /
slipstream?

Now, if it was only quiet enough to tolerate in your back yard,
everyone would want one. The tranny design is a doddle kept secret
by commercial mil / ind complex, its an automotive differential,
with one half turned inside out.

Terry K