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Old 09-23-2020, 02:20 PM
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speedracerntrixie's Avatar
Join Date: Jun 2010
Location: Happy Valley, Oregon
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The problem with flaperons ( down for flaperons, up for spoilerons ) is that they tend to promote tip stalls. Reason being is that on an Ultimate the ailerons go all the way to the tip but are usually only about 2/3 span. Imagine you have the flaperons dropped 15 degrees and then add a good dose of aileron control. You could easily stall the outboard section of the wing with the aileron/flaperon with the downward travel. Especially bad with a bipe due to the positive stagger between the two wings. When the bottom wing stalls before the top wing it effectively moves the CG rearward. You can imagine what mess that could create.

If you are worried about landing speed there are better solutions. First and foremost would be to reduce overall weight as much as possible. The other is to not have an overly forward CG. An overly forward CG requires constant downforce on the tail to keep the nose level or as the case while landing slightly nose high. To get this downforce you need up elevator in the form of elevator trim or while flaring for a landing back stick. You need airspeed to make either of those two things work, hence faster landing speeds. Being a big fan of bipes ( I have 3 ) with my favorite scale bipe being the relitivly unknown Reed Falcon. My 54" version is a porky 9 lbs but still lands fairly slow due to having the CG reasonably close to the nuetral point.

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micro270 (09-24-2020)