Yes.I'm probably being a bit dim but, in the absence of a tail rotor and with the requirement that both rotors rotate at the same speed, how does it perform a static turn? Is it as simple(?) as adjusting the pitch of the blades on one rotor (and compensating for all Newton's laws)?
Imagine two helicopters joined together.
Or a Chinook.
One rotor is supplying lift, while the other is supplying lift plus lateral thrust.