Re: Personal Flight [a variant of AirCars]

Spike Jones (
Sun, 19 Sep 1999 13:39:02 -0700

> > > I think we may have a real solution for the Jet Pack
> > > vs. Air Car debate. Check out
> >
> > If they are able to control this thing, I could believe
> > ranges of 50 to 80 km with speeds of up to about
> > 100 km/hr. Whaddya think, Doug? spike
> >
> > Doug Jones wrote:
> Well, that swagger stance would get uncomfortable in a hurry- I wrote to
> solotrek a month ago, suggesting a set of footpegs inboard of the vehicle's
> legs.

Ja, I ignored that. I imagined a cloth sling kind of seat, not so different from those found on a hang glider, with a minimal tripod (sans wheels) landing/support gear. This is order to save weight.

> The photos of the prototype showed a *huge* control authority- large
> pitch motions of the fans, both collectively and differential, could induce
> excessive rates.

I had imagined some microprocessor based control system using inputs from ring laser gyros and such, with little input from the meat. Biounits cannot be trusted with such tweaky and dangerous control tasks, as you may recall from my comments regarding Rotary Rocket. The THAAD system demonstrated how very competent automated control has become.

> Even with those fairly large fans, the power demand will be very high, and
> weightlifting capacity limited.

Ja, my thoughts exactly. When looking at the air car concept, I never got as far as the control or practicality aspects, for the power to weight numbers did not look sufficient to get off the ground, never mind achieving the wildly exaggerated performance numbers that were being quoted.

With this dual tilt rotor concept, they appear to be close to the power to weight numbers that will get them off the ground, however I suspect that the fuel carrying capacity will be small. I will go so far as to say: a Gina Miller sized person might be able to fly such a device, whereas a Lee Crocker or Greg Burch would be outta luck. Their design looks like it could still shed a few kilos, but the numbers are close to what I calculated, using a light 4 cylinder 2 stroke racing engine, 130ish horsepower, already developed by the motorcycle crowd.

The thing will be dangerous and noisy as all hell, but I am not arguing for the practicality of the device for the general proletariate. As a special purpose military machine, perhaps, and all-around cool toy, it would kick ass, would it not? }8-] spike