RE: four rotor toy
Well you make a case for the Osprey-
however
The craft does not rely on ducts - those are just there for safety reasons.
Electric motors of this type setup have a rotor and two bearings.
Those are the only moving parts -so- a central motor and drive shafts are really not required
The inherant safety and simplicity of individual electric motors along with the proven track record of these type motors , makes the configuration far better (my opinion) than the involved setup of the Ospry.
If you think I don't like the Osprey concept - you are correct.
My bet is that this multi type setup will end up replacing the involved setups -once the political forces driving the Ospry type machines , is exhausted.
Involved and expensive military equipment will be less attractive in the future (my opinion again)
The costs of maintaining this approach to insuring our nation's safety is becoming more and more contoversial.
The industrial /military complex is not a myth.
I am not a Dove - just looking at what could be a far more practical approach.