Two further helicopters on similar lines are also projected. The four rotors of this helicopter are mounted laterally on outriggers in two tandem pairs. The control mechanism is extremely simplified and obtained by differential change of thrust between the rotors. There is no cyclic control, but only collective control. In the experimental prototype the fuselage was of tubular steel, the booms supporting the rotors in aluminium alloy.
Power is provided by two engines connected to the rotor drive system by multiple vee belts.
Shafting and transmission cases ensure inter-connection between the four rotors, so that at need either engine can drive all of them. There is a tricycle undercarriage with two wheels in the rear section and a nose wheel which can swivel. The first flights took place in March 1956. The system was designed so that almost any combination of collective pitch changes could be introduced into the four rotors, thus varying the rotor thrust and yielding powerful control. For example, to roll the Quadrotor to one side, the pitch of both rotors on that side would be increased while the pitch of the two rotors on the other side was decreased.