Recently, Gary Drescher posted:

"Neil Gould" wrote in message
.. .
This makes *no* reference to the amount of lift that a stalled wing
provides beyond it being inadequate to support flight,

Interestingly enough, a stall occurs at the critical angle of attack,
which is the AOA at which the coefficient of lift is the *maximum
possible*. Just past the critical angle of attack (that is, further
into the stall), the lift coefficient is no longer maximal, but is
still well above what it is in ordinary cruise flight.

What *does* happen just past the critical AOA--that is, just into the
stall--is *not* that there's insufficient lift to support the plane's
weight, but rather that there's a loss of *vertical damping*. John
Denker (a physicist and a pilot) has a nice explanation he
http://www.av8n.com/how/htm/vdamp.ht...rtical-damping.

Thanks for that! I'm not sure that resolves the issue of trying to land
with these parameters.

Wrong. "To be a scalar" it needs to be a single value. And it is.
Angle-of-attack is just an angle. A single value.

Wrong. A scalar can not contain elements of direction by definition.
Ergo, AOA has no meaning as a scalar.

No, an angle is unquestionably a scalar, not a vector. Check any
introductory math text. If an angle were a vector, then a symbol
representing an angle would be set in boldface; but it is not.

Mathematically, an "angle" by itself *is* a scalar, and I'm not arguing
otherwise. I'm saying that "Angle Of Attack" requires direction to have
meaning. Without direction, there is no AOA.

You're right that an angle is defined by reference to vectors, but so
is (for example) the *dot product* of two vectors (yet the dot
product is a scalar); or so is the *magnitude* of a vector (but the
magnitude is a scalar). So being defined by reference to vectors does
not preclude a quantity from being scalar.

Well, OK. Then, how do you determine the AOA when the aircraft is parked?
If the component of direction is inseparable from the definition of AOA,
how can it be a scalar?

Neil