Funny dual rotor setup :

http://www.kamanaero.com/helicopters/kmax.html  (interesting embedded videos in this link).

a lot to learn from this video (a) Sychronous contra rotating Rotor, in RC it will mean a lot, more power and better manoeuvres (b) No Hydraulics, Servo Operated flaps, No bullets to puncture hydralic tanks etc (In life i have had many Hydraulic failures and once lost both hydraulics on short finals, Tuch down and the stick froze , and i froze too, thinking that, would have happened if it did, couple of sceonds earlier) hydraulics is an Achilles heels, a necessary one at that. (c) non involvement of an on board pilot  in the support operations means troops will be better supported.

Anwar Bhai
Thanks for sharing