Williamknowsbest wrote:
> Ducted fans can be quieter and more efficient than free rotors of the
> same diameter operating at the same rotor speeds
>
>
http://www.esotec.co.nz/hb/HTML/DuctMyths.html
>
> Saying that winged vehicles are necessarily less efficient than
> wheeled vehicles and so they cannot ever compete is like saying that
> rubber tires on asphalt is necessarily less efficient than steel
> wheels on steel rails so automobiles will never compete.
>
I didn't say "winged vehicles", I said VTOL vehicles like helicopters.
You can make a very fuel-efficient miniature aircraft, like the Rutan
VariEze - which got right around 26 mpg while flying at 180 mph.
Unfortunately, now you need runways at both the takeoff and landing end
of any flight, which limits flying it out of your garage.
The accident rate wasn't anything to get excited about either - with
around 800 built, there were 130 accidents, of which 46 were fatal:
http://en.wikipedia.org/wiki/VariEze
> Moller has been ineffective because he hasn't had the $3 billion
> needed to make such a system work and likely doesn't think about his
> market and so forth - merely the technical issues facing him at any
> time.
