The two counter rotating crankshafts share the same combustion chamber, so the engine casing remains free of any reaction torque even at extreme changes of revs and load.
It is better to have no torque at all, than to have to offset the torque from rotor / engine.
And the rider has pleasant things to do than struggling to keep his flying vehicle stable.
When a child begins riding a bicycle, it progressively learns how to react properly to the signals from the eyes and the body (i.e. on how to keep the control).
Just like driving a bike, the eyes / body of Libellula's rider are the sensors and the control system: he can soon discover the way to react properly and to keep the control.
In a Portable-Flyer it is better to use the body of the rider as the main sensing and controlling equipment, than developing and paying and carrying stabilizing and flight management systems.
Time will prove whether flying with Libellula is more difficult than riding a bicycle.
Click on any of the above images to download the respective windows "exe" controllable animation.
This propulsion unit is: direct injection Diesel, lightweight, vibration free with minimized total momentum of inertia enabling way easier direction change.
It improves the lightweight, the durability, the safety, the stability and the easy handling of small airplanes.
The maximal total range increases, while the emissions and the fuel cost decrease.
A forwards force and the weight of the engine/rotors are the only loads the frame of the airplane receives from the propulsion unit.
A sudden change of the engine load (WOT to stall, for instance), or a misfiring, cannot destabilize the airplane.
Intellectual Property: patent US 7,909,012
patent GB 2,449,031
patent AU 2007209302
Click on the image below for the QuickTime 5 MB video: