I think it's time that I wake up on this beautiful Chicago day and realize
that I have once again spent more time talking than listening, with the
consequence that I have managed to talk my head completely up my ass. Which
generally leaves one talking out there ass! Unfortunately, I do that
sometimes.

I'm reasonably intelligent, logical, and creative, and often that allows me
to come up with some really good conclusions and solutions. But I sometimes
fail to remember that others may have gotten there and gotten it right long
before I even start down the road.

For those of you who have spent your time and energy trying to help me "get
right with God" on this subject, I truly appreciate your patience and help.
I will try to do more listening than talking in the future.

For those of you who long since gave up on me, I admit to sometimes being
the donkey in the parable about the donkey and the brick, and it sometimes
takes a few licks with a few bricks for me to get the picture.

For all of you who simply put up with my lack of knowledge; thank you.

For those of you who tried to help me and teach me something; thank you. I
will try to be more receptive in the future.

And to all of you, my sincerest apologies for being such a pain in the ass.




"Todd Pattist" wrote in message
...
Peter's comments on this are right on.

I'll add a bit to the difference between a landing and a
"level" stall in flight. As you may recall, the total drag
on an aircraft is the sum of induced drag and parasitic
drag. The induced drag is high at low speeds and parasitic
is high at high speeds.

Anyway, as you slow in your attempt to produce a level
stall, induced drag rises very quickly (by a factor
proportional to one over the airspeed squared.) This rapid
drag rise causes a descent that quickly increases the angle
of attack of the wing to above the critical angle and thus
you quickly get to the stall and beyond it., producing a
loss of lift and the continuation of the descent.

During landing, the increased induced drag tries to cause
the same descent you experienced aloft, but fortunately your
wheels are there to catch you, and you never get the rapid
AOA increase that you got aloft, so you never get a true
stall.

"Andrew Sarangan" wrote in message
. com...
You guys are challenging my understanding of landings :-)

Challenge is good for the soul.

The landing technique, as taught by many before us, is to
progressively increase elevator deflection to maintain zero vertical
speed.

That's the ideal. In practice, it's nearly impossible to obtain exactly
zero vertical speed, and it's bad form for your vertical speed to go
positive (i.e. start to climb). In a properly executed landing, vertical
speed is always negative (i.e. a descent), and one typically reaches the
runway before reaching the critical AOA.

I suppose it is possible that you can reach max elevator
without reaching critical AOA.

Certainly once the main gear is on the ground, it is. I commonly
continue
to increase elevator back pressure after touchdown, so as to allow the
nosewheel to touchdown gently, and may well reach max elevator travel
before
allowing the nosewheel to touch. But this is a red herring in any case,
as
there is no requirement nor even a recommendation to reach max elevator
travel during a landing.

But I think that is unlikely, because
that would mean you will never be able to perform power-off stalls in
level unaccelerated flight.

At least one plane does have this characteristic (Ercoupe). Landings in
that airplane, one in which it is impossible to stall (in level
unaccelerated flight, anyway, such as one would experience during a
landing), are pretty much just like landings in any other airplane.

A typical "normal" landing involves flying a slightly fast approach speed
(1.2 to 1.3 Vs0), and then flaring and touching down while still above
Vs0.
One hopes that during the flare, airspeed is reduced to as close to Vs0
as
possible so as to minimize touchdown speed. In optimal conditions, a
well-executed landing will even be done with the stall warning going off.
But touchdown itself should still occur prior to the stall occurring
(which,
of course, prevents the stall from occurring at all).

Bottom line: just as George said, "no normal landing involves a stall".

Pete


"It is possible to fly without motors, but not without knowledge and
skill."
Wilbur Wright