Who does flight plans?

Recently, Peter Duniho posted:

In particular, Todd's comment simply corrects the statement that "when
you're stalled, you're falling, not flying". Using power to keep
oneself aloft is still "flying", even if the wings are stalled.
Thus, it is not always true that "when you're stalled, you're...not
flying", even if it IS true in most situations.

Then, the issue is one trying to make an absolute statement out of one
intended only in the context of the discussion, specifically, "full stall
greasers" in the typical SEL aircraft. Any discussion about other forms of
flying, whether it be in hovering Harriers or personal batwings are
irrelevant to that context.

In other words, what Todd is saying is that lift doesn't just quit in
a discontinuous way at the stall. If you look at the graph of lift
versus angle of attack, the peak of that graph occurs right at the
stalling angle of attack, and then starts to drop off from there. It
does drop quite a bit more rapidly than the other side of the graph
where lift is increasing, but it doesn't just jump to zero.

I wasn't claiming that it does. It's just that the amount of lift after
stall isn't sufficient to be relevant.

There are, of course, other issues. The graph I'm talking about is
actually the lift coefficient graph; actual lift depends on the lift
coefficient (angle of attack) and airspeed. Drag increases
dramatically at stall, and it would require a lot of extra power to
maintain an airspeed sufficient to produce lift equal to the
airplane's weight, flying just past the stalling angle of attack.
But it certainly is theoretically possibly.

Of course, if you have enough power. That's why my original reply stated,
"Think F-18..." This theoretical possibility isn't very relevant to the
context of the post to which I originally replied, e.g., "full-stall
greased landings" in a typical SEL.

Second Point:
It is exceptionally difficult to actually get to a full
stall attitude for landing. What is often called a "full
stall landing" or "3 point landing" does not actually have
the wing at stall AOA. Many aircraft would hit their tail
if they were low enough to safely land and the wing was at
stall AOA.

I completely disagree with this notion. The AOA is a vector of the
relative direction of travel through air.

The AOA is the "angle-of-attack". It's not a vector at all, never
mind the one you describe. It is true that the AOA is relative to
direction of travel through air (ie the "relative wind").

One doesn't have directional motion *without* a vector. ;-)

"Vector...Etymology: New Latin, from Latin, carrier, from vehere to
carry -- more at WAY
1 a : a quantity that has magnitude and direction and that is commonly
represented by a directed line segment whose length represents the
magnitude and whose orientation in space represents the direction..."

When one refers to the "angle of attack" (and, yes, I know that "AOA" is
the acronym), one is definitely referring to motion having both direction
and magnitude. "Relative wind" is just a non-technical way to state this.
However, it would have been better stated if I had said "... relative
direction of _the wing's_ travel...", even though the typical SEL's wing
pitch isn't drastically different from the rest of the aircraft. ;-)

There is no requirement that
there be a nose-high attitude in a stall, only that the wind
traveling over the wing is lower than what is required to produce
lift. It isn't difficult to hold a typical SEL aircraft in a
nose-down stall, and in fact, a descending turning stall is a
required manouvre in the private PTS.

Read Todd's statement again. He is clearly talking only about the
situation during a landing. The motion of the aircraft through the
air just prior to touchdown is necessarily nearly or precisely
parallel to the ground.

My reply specifically separates the AOA from any ground reference.

And it is true that with most airplanes, the
stalling angle-of-attack produces a pitch angle so nose-high that the
tail will hit the ground before the main gear does.

I responded to that. In the context of landing, if one flies slowly enough
to stall, one can stall "flat" relative to the ground because the decrease
in forward "relative wind" increases the AOA. That is what my remark
addresses.

You are certainly correct that an airplane can be stalled in any
attitude. But that in no way provides a basis for disagreement with
Todd's statements.

I think it does with regard to necessarily hitting the tail before
stalling.

Neil