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Old Sep 09, 2012, 05:10 PM
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Originally Posted by Kickstart View Post
i'll take that as a yes then..
It will have the same difficulty with up wind, cross wind and no wind.
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Old Sep 09, 2012, 05:54 PM
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Originally Posted by kaptondave View Post
OK, clearly I do not believe that the scale of a model has anything to do with the downwind turn stall debate but if you believe it is a factor maybe you can tell me how.
I don't either believe or disbelieve that scale is a factor. My point was that the person who brought it up thinks it is worth considering as a possible factor, and therefore, he was not off-topic.
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Old Sep 09, 2012, 07:47 PM
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My point was that the person who brought it up thinks it is worth considering as a possible factor, and therefore, he was not off-topic.
I would agree except that there has been no proof of his premise. The poster has postulated on rate of turn relative to bank angle, the relative size of control surfaces, power to weight ratio and prop size, all of which are scaling factors but none of which are relevant to the topic of stalling or not stalling on downwind turns. With this absence of proof the premise becomes off topic. Moreover he has twice posted false allegations about claims supposedly attributed to me, the most recent being that I could turn a full-scale plane at the same airspeed as a park model. Enough already.
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Old Sep 09, 2012, 10:37 PM
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Why so serious?
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Old Sep 10, 2012, 04:26 AM
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Originally Posted by Kickstart View Post
i'll take that as a yes then..
It was a no, actually. When flying close to stall speed, all turns are 'dangerous' because the reduced lift in any bank will bring the plane closer to stall.
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Old Sep 11, 2012, 05:40 PM
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Originally Posted by sablatnic View Post
It was a no, actually. When flying close to stall speed, all turns are 'dangerous' because the reduced lift in any bank will bring the plane closer to stall.
Actually, to make things clearer we probably should refer to flying at close to stall angle of attack rather than speed.

By saying we're flying at close to stall angle of attack, it makes much clearer the implications of banking the plane and asking the wings for just a little more lift
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Old Sep 11, 2012, 08:25 PM
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Actually, to make things clearer we probably should refer to flying at close to stall angle of attack rather than speed.
I don't think so. In full size planes there is no way for the pilot to measure angle of attack, but he does know his airspeed. Aircraft manuals clearly state stall speeds, but say nothing about AOA. With RC models the pilot has no way to measure either one but speed is the easier to visualize and better understood parameter.
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Old Sep 11, 2012, 08:35 PM
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Here is a great visual to help see why there are so many problems with wind. As you can see in the rectangular course you have to turn greater than 90 degrees to establish a crab angle on your base leg, and on your up wind turn to cross wind it will be less than 90 degrees. In the turn around a point you will see how your bank angle needs to be adjusted to keep your ground track consistant. The higher the wind the greater the range of bank angles. At lower pattern speeds instead of increasing bank angle you should just start your turns sooner and anticipate your crab angles.
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Old Sep 11, 2012, 08:41 PM
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Originally Posted by kaptondave View Post
I don't think so. In full size planes there is no way for the pilot to measure angle of attack, but he does know his airspeed. Aircraft manuals clearly state stall speeds, but say nothing about AOA. With RC models the pilot has no way to measure either one but speed is the easier to visualize and better understood parameter.
In full scale the feel is even better, especially at slow speeds. With the models while we don't actually feel the controls you can correlate how the plane responds at cruise speed with your control input and how it responds at close to stall speeds. You eventually get a "feel" for that "mushy" control response near stall.
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Old Sep 12, 2012, 01:19 AM
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Originally Posted by kaptondave View Post
I don't think so. In full size planes there is no way for the pilot to measure angle of attack, but he does know his airspeed. Aircraft manuals clearly state stall speeds, but say nothing about AOA. With RC models the pilot has no way to measure either one but speed is the easier to visualize and better understood parameter.
I know plenty of military aircraft have AOA indicators.
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Old Sep 12, 2012, 01:20 PM
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I know plenty of military aircraft have AOA indicators.
And that is relative to avoiding stalling an RC plane how?
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Old Sep 12, 2012, 09:12 PM
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And that is relative to avoiding stalling an RC plane how?
And that is related to unicorns and fonzie bear how?
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Old Sep 13, 2012, 10:03 AM
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And that is related to unicorns and fonzie bear how?
Oh goodie, we have a Troll.
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Old Sep 13, 2012, 02:56 PM
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Oh goodie, we have a Troll.

I am not sure about seeingeyegod being a troll. Maybe he is just fed up listening to the urban myth about the dreaded downwind turn.

;-)

What i mean is, that if you are flying over an airfield that is travelling with a speed of 800 mph, with a tailwind of maybe 790 mph. those ten miles will not do much difference, will they?
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Old Sep 13, 2012, 05:43 PM
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Originally Posted by kaptondave View Post
I don't think so. In full size planes there is no way for the pilot to measure angle of attack, but he does know his airspeed. Aircraft manuals clearly state stall speeds, but say nothing about AOA. With RC models the pilot has no way to measure either one but speed is the easier to visualize and better understood parameter.
Yes and full sized pilots should also know that wings don't give a damn how fast the plane is flying, they WILL stall at any speed when you exceed the critical angle of attack. The pilot should be able to feel when the plane is approaching stall and the stall warning alarm should be telling him that. If any pilot's looking at the airspeed indicator thinking he's got plenty of airspeed left according to the manual while ignoring the mushy (or shaking) stick and the blaring horn, then he's a danger to himself and others.
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