| Type: |
Aileron slope plane |
| Wingspan:
| 76" |
| Wing Area: |
??? sq in |
| Airfoil: | Flat bottom
|
| Weight: | 48oz |
| Construction: |
Styrofoam fuselage and wings with wood reinforcement |
| Controls: | Aileron, rudder, elevator |
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About 10 years ago, for reasons to this day I don't understand, my friend and I decided it would
be a good idea to add ailerons to a Spirit of '76.
Why? I don't know. We already had a few aileron slopers between us, so there was really no
good reason. At any rate, we proceeded to buy a new Spirit of '76 and some aileron stock and
let the modifying begin.
The first step was to slice off the foam trailing edge of the ridge and replace it with the ailerons. After we were finished cutting, we realized we had a problem. The ailerons stock we had was not thick enough to match up with the airfoil of the wing where we cut it. Now, the sensible thing to do would be add some balsa sheet to the ailerons to thicken them up. We did not do the sensible thing. Instead, we decided to extend the wing backwards with a sub trailing edge, so that that thickness tapered down to the same thickness as our aileron stock. This involved gluing a rather sizeable piece of blasa down the entire span of of each wing, then sanding it down to follow the profile. We then added the ailerons to this. So, not only did we add a weighty chunk of wood to each wing, but we also altered the airfoil by increasing the chord.
So, now we've got a Spirit of '76 with a wing that's really heavy, and has an odd airfoil.
Time to test it. It flies terrible. This airplane had the worst adverse yaw problem I'd ever seen. Putting the plane into a bank with lots of aileron makes the nose rise like you were trying to fly knife edge! I'm not sure why it was so bad...perhaps it was because we had 2 meters worth of strip ailerons. Still, I've seen other planes do fairly well with big ailerons, such as an aileron-winged MAD Highlander, and they didn't have anything like this amount of adverse yaw. It essentially made the plane unflyable. Well...it would fly, its just that you wouldn't want to fly it. We basically gave up on it.
Just recently, I decided to try it out again, but with some mechanical aileron differential added. It helped a bit, but it still flew pretty badly.
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