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In a message dated 2/24/02 1:24:30 PM Eastern Standard Time, [EMAIL PROTECTED] writes: > could be wrong here, but it seems that a large pilot and passenger, will > actually have a c.g. shift to the rear in this nose high attitude. No, you're not wrong. But the shift rearward is only relative to an observer on the ground. The CG of the airplane has not moved one bit relative to the airframe. In other words, if you draw a side view of the airplane and mark the CG both fore and aft, and "up and down" then rotate the picture, the position of the CG within the airframe has not moved. The thing that matters is the position of the CG relative to the center of lift, which is generally expressed as a percentage of Mean Aerodynamic Chord. Even upside down, this relationship does not change. Having said that, I guess if there were an aircraft where the CG was very high above the wing, and the CG were very close to the center of lift, then raising the nose could conceivably shift the relationship of the two relative to the gravity vector enough to affect the stability of the aircraft, but then that's why we have certification limits in the first place. Such a plane would very definitely be loaded outside its envelope. Bottom line, in a certificated aircraft, loaded within its certification envelope, raising the nose will not shift the CG far enough to make the plane unstable. Carry this thought a little farther and you can see that if the CG is in that relative position (boy, I wish I had a white board...) the wing would lift and the CG would fall until the plane rotates backward and the nose is once again pointed down and the CG is once again "forward" of the center of lift. Now, once again, after doing a bit of a tail slide, all is right with the world. Eventually, any plane will do that as long as the CG is in the right place to start with. Clear? (Yeah, right!) John ==^================================================================ This email was sent to: [EMAIL PROTECTED] EASY UNSUBSCRIBE click here: http://topica.com/u/?aVxiLm.aVzvvT Or send an email to: [EMAIL PROTECTED] T O P I C A -- Register now to manage your mail! http://www.topica.com/partner/tag02/register ==^================================================================
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