"GTH" wrote in message
...
Gerry and all,

Been following this most interesting conversation on aircraft design.
I would just point out some issues that one is to consider when
endeavouring to devise his own desin.

Then where WOULD be the right starting place?


This is the most important point. It is unwise to start thinking of
SOLUTIONS ( number of wings, biplane, delta, tandem wings...) before
posing the PROBLEM, and establishing what the aircraft will be required to
do.

I understand that this particular airplane should be small, light, and
able to take off from an unprepared stretch of private road. And it should
be storable in a garage.

There are several designs (some of them out of the US) that fulfill these
requirements, without resorting to exotic or complicated technical
solutions. And yet have outstanding handling qualities, payload and
performance on a reasonable power.

The MCR 01 two seater is one of them :
http://www.avnet.co.uk/lts/pages/mcr.htm


Thanks for your response, Gilles. A bit of clarification, perhaps. This is
not really a design to fullfill a mission. It's more of a "why not"
exercise. The very short wingspan is the only real design criteria, and it
is just my idea rather than a definite need anyone has. The MCR 01 is a
very interesting design, but with a wingspan of over 20 feet it doesn't fit
my plan. Consider that if you made it a 10 foot span biplane it would
perhaps fit the bill?? I could restate it this way, if you divided the 20
foot wingspan of the MCR 01 into two wings either tandem or stacked would it
provide similar performance? How about 4 10 foot wings with one foot chord?
I don't really know the answer, I'm just brainstorming to see if anyone else
knows the answer.

Gerry



the dimensions of your wings...

First - learn about Reynolds number.
Okay

Very few of the published airfoils work well below about 3 meg RN.

What does that mean in regard to your choices?

Well, the two-foot chord wing is going to have to move pretty fast to
make
3 meg RN.

The MCR 01 has a two foot chord wing, and the four seater we built has a 3
foot chord.


Concerning the Delta Dyke, one of my buddy owns one, and it is certainly
not an answer to the original poster's requirements. On the contrary, it
is a dog in flight, and very tricky. Deltas are definitely not a corrrect
solution to any slow airplane.

Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr