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Old 03-05-2009, 11:33 PM   #14
sukhoi26mx
Scott Stoops
 
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Join Date: Feb 2006
Posts: 626
Default Re: high stabs? full scale airfoils?

Quote: Originally Posted by Mithrandir
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then get a Yak 55

It is scale when it is all lined up!!!

Bam Bam.... the coupling is not a function of thrust-wing-stab alignment.... it has to do with very asymetric flow around the fuse, fin and rudder.... There is a fin adjacent to the top side of the stab and only a rounded stubby fuselage bottom surface adjacent to the lower side of the stab...... Often it is hard to completely design out as P-Factor from the prop prolly adds an element of irritation to the mix
Pitch coupling has everything to with with wing/stab/thrust line alignment relative to the center of pressure of the fuse... while roll coupling has everything to do with wing position and effective dihedral/dihedral from the wing/stab placement, and wing/stab taper ratios.

The reality is that full-scale airplanes aren't optimized for coupling - period. Their wings and stab are placed for convenience and structural integrity. For instance, most tails are mounted high as that is the most convenient place to mount them structurally. As a second for instance, most wings are either high or low (think Extra 300 vs. Cap or Sukhoi) so that the pilot has a place for his/her legs (above or below the spar). Those kind of compromises aren't necessary in models, and I agree with Mike that they should be designed out when possible without compromising the fundamental feel and personality of the airplane.

Scott
full-scale Sukhoi 26mx pilot
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