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Old Dec 04, 2012, 01:52 PM
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I like real wooden aeroplanes!
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South-west France
Joined Sep 2007
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Hi Chris

I've watched the video again several times and realised I have seen just such a "flight pattern " before, and on that occasion I was holding the transmitter! The model in question was my RBC kits Spitfire II, powered by a 2.5:1 geared Speed 600. The first couple of flights were fine, but on flight three, as I turned finals, it did just what your model did and I too just avoided the ground. This, of course, is an aileron model. I decided I had just slowed it down too much and continued to fly it, but over the next month the same thing happened several times and it just became too nerve racking, culminating when it actually did hit the ground, albeit with only minor damage. The model was fine when flying at full, or close to full, power, but turns at reduced throttle on the landing approach were always an accident waiting to happen.

The reason I mention this is that the wing shape is, of course, very similar at the tips to your model. I eventually concluded that the CG just had to come forward and added some nose ballast, but also raised both ailerons by 1/8" to introduce a little effective aerodynamic washout. The effect of these changes was dramatic and almost twenty years later I still have the model and it is an absolute pussy cat to fly and can be dragged around low and slow turns with absolute confidence. In view of your CG issues, I hesitate to suggest even more weight up front, but maybe it might need it. Or perhaps you could try steaming a bit of washout into the tips?

Despite the model having a 12" x 10" (folding) prop (lots of torque) I never experienced any funny behaviour on opening the throttle, in fact rather like yours that was what saved it on several occasions.

May all be irrelevant, but your model's gyrations certainly looked very similar! Best of luck with finding a solution.
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