Re: will aircars destroy the auto industry?

From: Spike Jones (
Date: Sat Apr 29 2000 - 15:25:11 MDT

> Spike Jones wrote: Even at 2 MPG,
> > there might be certain circs where such a device could be useful however.

> Michael S. Lorrey wrote:
> Even normal existing aircraft get better than 2 mpg, Spike. Even
> helicopters do better than that, not much better, but better. Can you
> post your calcs?

Roger that, but let me put em in a spreadsheet format so anyone
who is interested can play.

Regarding ordinary aircraft, I agree, however ordinary aircraft are
not capable of vertical takeoff and landing. Helicopters have much
higher wing area and are therefore more efficient fliers. The advertised
version of the Moller aircar has the only real lifting surface that I can
see arranged so far aft as to be practially useless for straight and
level flight: it would need to rely on large amount of hard-won
diverted thrust from the two forward ducted fans for lift. What
is that about?

Nowthen, there is a single-prop aircraft that has enough thrust to
hang on its own propeller, that aerobatic hotrod that Wayne
Handley crashed down in Salinas last year, the turbo raven. That
was something to see: he could fly low and nose up, pull it to a stop,
even go down slightly, then hit the throttle and go straight up. Cooool!

But of course it has an enormous propeller for that sized craft
and you lose efficiency as you reduce the size of the rotor,
so it should not surprise us that the aircar, with half again
the mass of the turbo-raven and those way small diameter
rotors should be a ravenous devourer of fuel.

Regardless, if a clever mechanical engineer did manage to arrange
a small VTOL like a miniaturized V22, it would still have its
uses, even if its fuel economy is 2 MPG, for special purposes,
such as an air ambulance for instance.

Mike, that 20 MPG number is a fantasy bud. Otherwise
its back to aerodynamics 101 for me. {8^D spike

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