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Old 10th Apr 2019, 12:47
  #3810 (permalink)  
Join Date: Nov 2018
Location: Brisbane
Posts: 19
Originally Posted by fdr View Post
back on planet earth, where Newtonian physics still reigns, you may find that for an aircraft to be statically stable, mass is always ahead of the center of pressure.

Agreed with the rest of your post, but as a counter-example to the statement above, consider a 737 NG loaded to it's absolute rear limit (36%MAC), and trimmed to fly at high but nonstalling AoA. It's CP will be relatively forward and close to but not reaching the wing aerodynamic centre of 25%MAC (will be approximately 32%MAC). CP is hence ahead of the CG and the tail is lifting slightly to maintain trim. However, the aircraft is still longitudinally stable, as although the tail is lifting it's local AoA is less than the wing. Of course this is an edge case for stability, more often CP is behind the CG in all flight regimes and the tail is always in downforce.
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