We are going to build an Airplane!
My wife and I have made a decision to build out own airplane. I have been building hot rods and classic cars since I was 15 years old. I had 6 years of woodshop in school, I can weld ok and can sort of usemy 1944 Loganlathe. I am also a collage boy, so I can sort of read and write.
We are building the airplane to hop around the USA in a slowand low fashion in 8 years when we retire. I can set aside 600-800 hours a yearfor this project. We drive 1940's Desoto's so you get the idea of what we areabout.
We want to build an airplane for several reasons:
1. We want to know the airplane inside and out.
2. We can build it out of cash flow.
3. Once done, we can do the maintenance.
4. We can include many innovations of the last 75 years that would be hard to do in a certificated airplane of pre WWII vintage.
5. We have an excuse to come to OSH every year!
What we want to build is a something of an oxymoron. We wish to build a three place "State ofthe Art Biplane".
Our airplane specifications are currently as follows:
A. With full fuel and oil a useful load of 1000 pounds.
B. A landing Speed of no more than 60 MPH clean.
C. Take off and land with 1000 feet.
D. A 75% power cruise speed of 90 MPH.
E. A max cruise speed of 110 MPH.
F. Maximum flight with 1 hour reserve 400NM.
G. An biplane with stability a prime objective over"fighter like" maneuverability.
H. A classic looking Biplane.
I. Preferable all the above at 12-16 GPH :-)
We realize that the above list may not be achievable. Some compromise will be inevitable. But for us it is a starting point.
I have been reading C.C. Carter's book on Simple Aerodynamics and The Airplane. One thing that stands out is that just as the science was really moving forward on the aerodynamics of wings that WWII dragged everything in a hurry to the direction of faster-higher loaded mono wings. This book seems to be the last thing (1940) that I could find that went into depth on the science of bi-wings.
I know that in the last couple of years at Stanford University some folks are doing computer modeling on a high speed high altitude bi-plane designs. I have tried to contact those folks, but alas, they don't seem to want to talk with us lonely home builders. They have constructed a computer model for bi-planes, I would love to get access to it for my project.
What I would like to know is are there any folks who are advisors for EAA members who are Aeronautical Engineers? I would like to talk with some folks thatcould discuss some of the things I have read in Carter's book. I sort of getit, but that kind of math was a long time ago for me.
Thanks everyone. Isuspect that the next 4 to 8 years is going to be an interesting journey.
So you are going to design and build your dream airplane? That sounds like a lot more fun than playing bingo or shuffleboard at the Sr. citizen luncheon! You are correct about compromise but I think your goals are very realistic. And FWIW, there are biplanes that get the high tech treatment - glass cockpit displays, etc. Keep us posted on your progress!
Looking at your requirements, the useful load will be the most difficult. Two homebuilts come to mind -- the Murphy Super Rebel or Moose, and the Bearhawk. There are generally un-started kits available that you can pick up for less than a new kit. Both use O-540s -- in your gph range.
Last edited by Jim Heffelfinger; 08-10-2013 at 07:43 PM.
Reason: more info
Thanks for the thoughts and suggestions. One thing that struck me as I have been reading up in Carter's book and other sources is that due to the cost and time required that NACA did not do nearly as much testing as could have been done on bi-plane design. I am hoping to find some folks that have access and interest in doing simulations of the many wings designs with various stagger and gap configurations available. With computerized simulations, they can go though many hundreds or thousands of configurations, something that is impractical with wind tunnel testing. There may well be some new ideas buried in such an undertaking.
When you get to the propulsion, you may want to consult Jack Norris about a propeller design. See: www.PropellersExplained.com .
Have you looked at Raymer's book?
If you haven't already done so, you might want to consider contacting the Antique Airplane Association (http://antiqueairfield.com/), in Blakesburg Iowa. Not only might they be a valuable source of helpful information, but they could put in contact with some very knowledgeable folks as well.
There were several 3-place, 2 in front-1 in back, vintage biplanes. Pick one of them as basic design and modify with modern engine. You will likely need to enlarge most slightly to obtain 1000# useful load. That high a useful load suggest you are looking for 400# plus baggage capacity? That may be the trick-where to put it to maintain W&B issues....? Maybe consider pods at or near CG? ( C-FYPM above is interesting for sure) Indeed, google the DH87, it looks pretty good. Will meet your goals for the most part on 120hp.......(and forget my "pods" suggestion above) If I was 20years younger I might build a modern DH87 myself.....
Last edited by Spezioman; 08-16-2013 at 07:21 AM.
I can definitely agree with Raymer's book. Jack Norris does have good info on prop design, but his book is a bit of a slog to read though. Great information once you get through it and understand it.
I would also highly recommend looking up the many articles by Neal Willford in the back issues of EAA. He wrote several articles in the early 2000s, and for a while the Excel spreadsheets with the articles were also available for download and use.
There is a ton of info on the net, but be careful you do not get overwhelmed by it all! (like me!) Keep us posted!
Last edited by Ried; 08-16-2013 at 09:00 AM.