Feel free to look me up on the FAA web. Certificated
airplanes are designed to not fully stall the wing or the
tail for that matter. But within the limits of what does
happen, and without discussing wash-in, wash-out, twist,
airfoil section changes, control stops, stick shaker and
pullers, gust loading, accelerated stalls, mushing, getting
a useable idea of what happens when the controls are applied
smoothly, violently or the airplane breaks apart in flight.

If the nose would always go down from a stall, spin chutes
would not be required. If the airplane is abused in flight,
it will do some pretty remarkable things. I know a Beech
test pilot who wondered about what would happen in an E90 at
cruise if you put the props into reverse. The airplane did
not break, but they were reported to have changed their
clothes after the flight. Same pilot tried the same thing
in an F90 with the T-tail and nothing really uncontrollable
happened.

It is possible to design a wing that will stall, 100% across
the entire span, but it won't be certified for civil use.

If the tail surface reaches max lift (down-force) and you
try to go slower, it will begin the stall as air flow
reaches the critical angle of attack on the tail
PROGRESSIVELY and the nose will drop because the moment
between the CP and CG will not be countered by the tail
forces. Do it slowly and the nose pitches down slowly.
Pull a few Gs and the reaction is faster and the degree to
which the stall progresses on the tail and wing is much
faster because inertia will carry the aircraft past the
critical angles at a higher kinetic energy level.


--
James H. Macklin
ATP,CFI,A&P

"Matt Whiting" wrote in message
...
| Jim Macklin wrote:
|
| Unless the wing is producing lift, there is no rotation
to
| reduce the angle of attack. If the wing was really
stalled,
| the airplane would fall flat, if it was spinning it
would be
| a flat spin, but if was fully stalled, it would be a
deep
| stall and would not rotate the nose down and it would
stay
| in the stall.
|
| The lift from the wing doesn't go to zero during a stall.
|
|
| Under normal conditions, neither the wing or the tail
fully
| stalls. Stall strips, wing twist or air foil changes
along
| the span keep the wing from reaching the critical angle
of
| attack at one moment in time. Also the tailplane is
usually
| a different airfoil and more heavily loaded and is
designed
| to begin shedding lift [down-force] before the wing.
The CG
| range is set so that a certified airplane will have that
| stable pattern.
|
| I'm now really curious to hear your definition of what
stall means.
|
|
| The weight of the airplane does not cause the stall
break
| rotation, it is the lift moment. If it was not for the
wing
| lift, the airplane's mass as concentrated on the CG
would
| simply fall as a unit in the same attitude as it was in
at
| the moment.
|
| No it won't because there is still some lift from the
wing, however, it
| is now less than the weight of the airplane so the
imbalance in forces
| causes the airplane to both descend and rotate. It would
only fall
| downward in a flat attitude of the lift (and drag) of the
wing and tail
| and fuselage went either completely to zero or remained
perfectly equal
| forward and rearward of the CG.
|
|
|
| If the center of pressure was located at the same
location
| as the CG, there would be no moment or force to cause
| rotation.
|
| Sure, there is still the force from the tail.
|
| Are you really a CFI and ATP as your .sig advertises?
|
| Matt