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Old 05-31-2012, 10:24 PM
Brian Carlton Brian Carlton is offline
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Join Date: May 2002
Location: Blue Point, NY
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Quote:
Originally Posted by LarryBible View Post
Also remember that the tail section is an airfoil as well. Air flow both under and over the tail section will cause lift. Air pressure on the top of the elevator would create down force.
Negative.

On these airliners, the tail section always generates downforce. It's the only thing that keeps the equilibrium in pitch.

The CG of any airliner must be forward of the center of lift. That's why the CG calculation is critical for every flight. The further forward the CG, the more downforce is required on the tailplane (and the more fuel is consumed due to drag).
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