A dumb doubt on stalls

"Matt Whiting" wrote in message
...
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.

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.

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?

There's a paragraph on p. 3-21 that makes part (but not most) of the
erroneous claim that Jim attributes to the publication. In particular, the
paragraph does say (in a discussion of a typical GA plane's normal stall)
that the tail loses lift (along with the wings). But it does not attribute
the plane's stall to the tail's supposed loss of lift; on the contrary, it
credits the supposed loss of lift with helping to recover from the stall.
(Additionally, the paragraph claims that the wings' lift *ceases* during a
stall, which is not the case.)

--Gary