I had a brain storm today on a roadable aircraft.
It is always in the back of my feeble mind :)

I realized one of the unique features of the rotary
is its very simple e-shaft. If one makes it longer and
larger in diameter on the front end  one can get power out of both
ends. One end is mated to a stock VW transmission and the
other end uses one of Ken Welters 3:1 cog belt reduction drives.

You take off in first gear and get much better acceleration to
flying speed. This is due to the traction you get out of tires
as opposed to a highly slipping prop. As soon as you run out of
RPM in first you push in the clutch and shift into neutral.
the prop takes over.

For road work you remove the canard and main wings
and tow them behind you. The only drawback here is the weight
of the VW gear box and drive shafts.

Its a motor cycle on the ground as that circumvents a load of
EPA and DOT rules.

Paul Lamar

Watch it Paul!!

Moller is calling!

TJ :))

I don't get the connection. It is nothing like a Moller Skycar.

Roadable airplanes ARE flyable. There are no technological
break throughs required. The vast majority of the
parts are off the shelf.

The main challenge is minimizing the weight penalty.
Most roadable aircraft designs use twin booms for the tail but
the Ruttan Canard configuration  is a better fit with roadable
requirements IMHO. To my knowledge nobody has tried the canard
configuration yet.

Paul Lamar

Paul,

I admire your drive to make a airplane roadable or a car flyable, BUT either
way you go, it is not very practical in any foreseeable future.
Once you are done with it it will not fly that well NOR drive that well AND
it will cost a fortune.

Better to keep the wheels down and the wings up.

HOWEVER both should be powered by a rotary!

Cheers,

Thomas J.

History would indicate so but I disagree. With modern high
strength to weight ratio materials and the canard configuration
the aircraft performance does not have to suffer that much.

There are a zillion VW rear suspension and drive line, three wheel
custom motorcycles on US roads and they suffer no performance penalties
what so ever. Particularly with Mazda rotary engine power.

Sure it won't be as fast as a Long EZ but it will get you there
a lot faster than a car. Especially to remote areas like Baja.

An honest person could make some money selling well designed
kits.

--------------------------------

With the gear retracted there will be near zero aerodynamic
penalties.

-------------------------------------------------

One of the design parameters one needs to pay a lot of attention
to on a roadable is the weight of the wheels and tires.
I suggest dragster forged aluminum front wheels and tires at 15 by 3 1/2
for the rear. You need diameter as the cruise RPM on
the ground using the VW tx requires a rather large diameter
tire.

The front tire can be a light weight motorcycle wheel
and tire. Motor cycle disc brakes will also keep the weight
down.

Paul Lamar

Konichi wa (good day)

After reading about the roadable airplane on the cover of PM magazine I
began to see that Pauls canard concept actually is more elegant.  Here are
some thoughts I summarized for a friend of mine over here that has interest
in motor gliders.

..........
Design the car body to be minimal in weight but high in strength.  This
translates to carbon fiber, foam and Kevlar sandwich body.  Pricey?  for
sure.  This means it must be designed and registered as a motor bike and as
such use similar parts. I would look at some of the solar racer cars you
that travel at 100Km+/an hour for suspension and tire ideas. You will find a
lot of bicycle and lightweight motor cycle components there. The car has to
be adequate for around town or short trips across country, with IMHO top
speeds of 80 km.. Slow?  Heh if you want to go fast, go back to the airport
and bolt those two long boards on the roof again:) Have two steerable wheels
in front and the drive wheel or dual wheels in back. Look at BMW motor bikes
and some models of Bridgestone bikes for how they handle the drive shaft
design. For a two seater side by side or even tandem, this gives it a wide,
stable, stance needed for rough roads and cornering stability. That work has
already been done.  Good designs actually lean into the turns. The single
wheel in front trikes tend to roll over very easily and hang up in rough
surfaces and swift braking tend to swap ends.

Give the car a small lightweight infinite variable speed transmission and a
reversing method.  For example take one out the single seater 50cc  mini
cars they have over here or the newer one seater electric minicars.  Use a
single rotor air cooled engine taking power off of both ends.  50 hp should
be fine for  both applications. Diamond Aircraft of Swiss is already using
such a small engine and Richard Sohn is working on one now. If the proof of
concept item was initially for a  canard pusher high wing motor glider then
there is a ready market.

  For instance; if caught in marginal weather land off airport and drive it
home or to a safe place. The wings  need to come off easily but not to
easily of course. The tapered wing spars (like the SeaWind) could in the
same manner bolt to each other and to the bulkhead with two bolts and
several positioning brackets on the small strake outside.  In car mode the
wings could pop upwards out of their retaining slot after being unbolted and
then  rotated backwards still held to the strake by a vertical pin. If at an
off airport landing they can be completely removed, and carried for a bit
get them out of the rough and on to a smoother road. The car could be push o

 The canard could stay attached to the front and has the LED
landing/headlights mounted into the leading edge as well as the turn
signals/navigation lights at the ends. The strakes can be the same width as
the canard thereby giving the 'car' some presence and avoid becoming road
kill from a passing 18 wheeler. Fuel is stored in the overhead strake tanks.
Brake and turn signals lights reside within the strakes.  I would love to
see this airplane fly if for no other reason than to witness it put on its
turn signals or brake lights when flying in the pattern.

Using Rutan's Solitaire  glider design would be a good place to start in a
proof of concept application motor glider. In addition  motor glider
propellers fold up to reduce drag.  Something you would need to do when
driving on the road unless you want to warn  the tailgater behind you.

As Paul pointed out so clearly, cars accelerate better than airplanes on the
road so take advantage of it until takeoff and when the wheels become
unweighted they they automatically disengage from the drive train.

Now add a inflatable structure, extend a  propeller into the water and it
might just become  more complex to make than a Seawind:)

Doug in Japan