DeadHeadingDuck
If you're having "fun" writing your own program, then go for it.
But here's something that might be just what you're looking for. You can download a 'no-save' demo version
http://www.davincitechnologies.com/AirplanePDQ.htm
Mike
Ghengis,
Have you read Raymer's "Aircraft Design: A Conceptual Approach" ?
I have that book, and it seems to cover just about everything for initial designing.
Is there anything in the "HomeBuilders" version that is not included in the A.D:A.C.A book ?
Mike