Tandem Flybaby Frequently asked Questions

Q: Do you plan to sell plans for your modifications?

A: The essential plans are already on the web page. The fuselage drawings have all the dimensions on them, and if you look at Pete's plans and substitute my drawings for his fuselage drawings You'll see how they fit. When the thing is done, I will probably flesh them out some and submit them someplace like Contact! magazine for publication. So the answer is: I won't sell them, but they are published. If you really want to see how it all fits, get the single-place plans from Pete, print out the fuselage drawings from the web page and build a 1/10 scale model. First build the single place, and then build a scale two place fuselage and fit the works together. I recommend this highly. You'll learn a lot from it. I did.

Q: Would I need the single place Flybaby plans to build a tandem?

A: Yes. They cost $65.00.
The address to get them is:
Peter M. Bowers
10458 16th Ave.
South Seattle, WA 98168

Q: Will the standard flybaby wings / tail / landing gear fit your fuselage?

A: I sure hope so. They are designed to. The tail is going on now without any problem, I haven't fitted the wings yet. The spar carry-troughs are 1" while the standard wings are 3/4". So if you fit the standard wings you will need to add 1/8" doublers under the steel wing spar fittings just to make the fittings 1" apart.

Q: Will the standard flybaby wings be strong enough? Are the standard spars thick enough? Will you increase the spar thickness?

A: A Champ carries a similar load and it has 3/4" spars. So does a Cub, and I think the Citabria does as well. I have thought of making my spars 1" thick, but I now think the wings I bought from another project might well do. They have 3/4" spars. If I build a new set of wings, I think I'll make built up box spars to save weight and expensive spruce planks. They'll have 3/4" sparcaps and 1/8" webs for 1" total.

Q: Will the standard flybaby wings be big enough?

A: Increasing the weight while keeping the wings the same will increase stall speed and landing speed. The only trouble I've heard from the two guys who built tandems before was climb rate. That is effected by wing loading, but power loading has a larger effect, and with the horsepower increase, I expect it to climb well. If the landing roll is too long for my tastes, I'll start fiddling with flaps, but with aggressive slipping I think it may well be fine the way it is.

Q: Did you use 1/8" plywood for the fuselage sides or did you go to 1/4"?

A: 1/8" is more than thick enough. 3/32" is thick enough but 1/8" is cheaper. I went with 1/8"

Q: Will the headrest/canopy blank out the rudder?

A: Flight test will tell, but I don't expect a problem here. I talked to a fellow who was thinking about building a tandem and had a single place. He built a mocked up canopy well back from the cockpit and flew it to see if there was a blanking problem. He found no problem.

Q: Is the tail big enough?

A: Again flight test will tell. I'll of course do stability and control testing, and we will see. How much stability you need is arbitrary. Some like more, and some missions require more. If I think it needs more tail I'll add it, but again I don't expect it to be needed. Neither prior tandem was reported to have stability problems. The big question about the tail is spin recovery. I have increased the polar moment of inertia, which tends to make a spin go flat. The fix if one is needed is to increase fin volume. I don't know if either tandem was spin tested, so I don't know if it tends to go flat.

Q: Shouldn't the diagonals in the top and bottom of the fuselage go in opposite directions?

A: They do. As it says on the bottom of the drawing, the bottom diagram is a bottom view. The top is a top view. That's a little unconventional, but it is the way you look at it while you build it.

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