First Time Designing. Where to Start?

[A Future Pilot]

Hello everyone!

So yesterday I finally bit the bullet and decided that the plane I really want doesn't exist, and I'll design it myself. I have a clear idea of what it should look like in my head, and I'm currently having a friend draw up some sketches of it (I'm terrible at drawing). Now where do I go from here?

It's a small, single-seat plane that I WANT to build under 254 pounds (it will use a Polini Thor 250, so it won't be a true ultralight, but I plan on releasing plans once it's finished and I want people to be able to build it as an ultralight). It will have a steel tube fuselage, and fabric covered wings and control surfaces.

So...how do I go about deciding on wing span/length of it? What about choosing an airfoil? How about general "will it fly, and how well" aerodynamics? What about structural integrity? Basically I know I have a LOT to learn, but I'm not sure right now where to even begin. Can any of you help me?

EDIT: Well after doing a bunch of looking around online I just bought "Simplified Aircraft Design for Homebuidlers". I'm also considering "The Design of the Airplane" by Darrol Stinton. I've heard that those books cover all the aerodynamics needed, but not the structural integrity. What books would y'all recommend for that? Or should I just find an engineer to help me with that part of it?

Thanks!

[Byron J. Covey]

So...how do I go about deciding on wing span/length of it? What about choosing an airfoil? How about general "will it fly, and how well" aerodynamics? What about structural integrity? Basically I know I have a LOT to learn, but I'm not sure right now where to even begin. Can any of you help me?

Start here http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/8950-technical-references-books-technical-papers-software-etc.html


BJC

[A Future Pilot]

Thank you very much!! Looks like those books will cover just about everything! :)

[Byron J. Covey]

Thank you very much!! Looks like those books will cover just about everything! :)

There are many people on that forum who are very experienced. Participate there, learn which posters to pay attention to, and which of us to ignore, and you will have the opportunity to get a sanity check on your design work.


BJC

[George Sychrovsky]

Start with learning why what you want doesn't exist already.

[FlyingRon]

If you don't have a good understanding of aerodynamics, I'd recommend John Lowry's Performance of Light Aircraft to give you a good fundamental understanding.

[crusty old aviator]

What will be a typical flight in your dream machine? How far, how fast, how long, how high? Or do you primarily want a plane that just looks like your vision, and actually getting off the ground is secondary? How much room does your body require in a cockpit, for however many hours you wish to stay aloft? Just about every aircraft designed involved a certain amount of compromise. What are you willing to compromise, other than safety? Martin Hollmann wrote some very good books on aircraft design. He passed away a while ago, so I'm not sure if AS&S is still selling them or not.

As for the design you mention: you'll have to minimize the amount of steel tubing you use, as it's heavy. The 36HP Thor weighs about 40 pounds, but after you add in the radiator, etc. and a prop and PSRU, you'll have about 180 pounds left for the airframe. Make her streamlined, or the drag will gobble up too many of your Thor's ponies to get you above stall speed. Don't forget to have fun with it.