"Phillip" wrote in
:

Also, I've seen some photos of early kit helicopters that
appear to have just a tilting head (no way to auto-rotate
?). Isn't this a bit of a death wish? Does a helicopter
need to have collective pitch for anything other than
auto-rotaion?

Helicopters depend on collective pitch for control of power -
they have no other way to fly. Without collective pitch, you
can't get off the ground, or change power, or get back on the
ground in one piece.

--
Regards,

Stan