A rotorcraft which only has one overhead rotor and no others.
I'm just going to throw this out there and see what happens.
In fiction if you want to make something fly and donít use rockets, you put a helicopter rotor on it. Quite often the rotor will just be the main lifting rotor attached to cars, boats, houses, and backpacks, and they fly about with no problem. Hereís what would really happen: if the rotor is powered by an internal engine, the force of the rotor turning actually produces a counter force per Newtonís Third Law that would actually cause whatever itís attached to to spin in the opposite direction. There are several ways to overcome this. Most helicopters have a smaller tail rotor or fan to provide horizontal thrust to keep it stable. Others, such as the CH-47 Chinook or V-22 Osprey use two main rotors that rotate in opposite directions. These can be on different parts of the aircraft, coaxial, or intermeshing (each blade of one rotor fits into the gaps between the blades of the otherís) Autogyros have an engine that provides forward thrust and uses the airflow to turn its rotor, avoiding the problem. It can also be avoided by placing the power source (mini-jets or rockets) at the tips of the main rotor. Not showing any of these may be a case of Artistic License - Physics. In any case itís Just Plane Wrong.