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  #29  
Old June 20th 06, 10:59 PM posted to rec.aviation.piloting
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Default A dumb doubt on stalls

Jim Macklin wrote:

The tail is more heavily loaded and at a higher angle of
attack than the wing. The tail lift is actually a tail down
force. You can look up a textbook on stability, control and
weight and balance to see that with a conventional tail, the
wing lift is located on the center of pressure, while the CG
is located some small distance forward of that point. The
tail provides a downward forced on the tail that creates a
moment around the CG to balance the moment arm between the
center of pressure and the CG.

When the pilot feels a stall buffet, it is caused by air
flow separation that impacts the tail or some other part of
the structure. But the stall break happens when the tail
stalls and the CG moment is no longer countered by the tail
down force.

On a canard aircraft such as Burt Rutan designs, the forward
wing is heavily loaded and lifts up and the main wing is
more lightly loaded and at a lower angle of attack. When
the plane approaches the stall, the forward wing stalls
first and the nose drops.
see http://www.faa.gov/pilots/training/handbook/
this is the link to the chapters you
need
http://www.faa.gov/library/manuals/a...83-25-1of4.pdf



I did a quick search and find nothing about the tail stalling before the
wing under normal conditions. On which page did you see this?

Personally, I don't believe this. If this were the case, then during a
full stall landing, the airplane would rise upward when the tail stalled
as the net force in the vertical direction would be greater upward than
downward. Yes the airplane would rotate about the center of lift and
the nose would fall, but the wing would be rising at the same time.
This isn't the way any airplane I've ever flown behaved.

Matt