Thread: Thrust ???
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Old 11-23-2005, 04:22 PM
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JohnW
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Default RE: Thrust ???

I was hoping for some new magical insight... but you basically confirmed my understanding. The tests you described would indeed detect an issue with thrust/CG/incidence, but it wouldn't necessary indicate which are off, just that the combination is off. Is that correct? I often struggle with other people's planes on this issue. I'm at a disadvantage because I have to take their word that they set the CG properly, built the model as per the plans, etc. and I often cannot verify this for them at the field. I've encountered a few planes that just acted screwy and I could not easily detect what was off, my guess was all three (thrust/CG/incidence) such that the plane trimmed for level flight OK, but had all sorts of other issues. I know any power off test will remove thrust from the equation, and any vertical test should remove balance point (CG) from the test. What I struggle with is making senses of the result especially when something is way out. I.E. a test may show down thrust is too much, but is that because it is set wrong or is it the CG or incidence that are set wrong that make the model act like it has too much down thrust when the thrust is actually set as per the plans. Any thoughts on that? Cheers.
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