Crossed Controls Stall?

On Jul 22, 12:47*am, Mike Rhodes wrote:
On Thu, 21 Jul 2011 10:31:18 -0400, "vaughn"

wrote:
"Mike Rhodes" wrote in message
news
By simple geometry the forward wing of a dihedraled pair in a skid
will have the steepest angle of attack, and the greatest amount of
lift, and therefore the one most likely to stall. *(Not the wing
inside inside of the skid.) *Aileron use will not change that --
except they force the aircraft to remain in a skid when operated
"crossed controlled."

Aileron use affects the effective angle of attack of a wing. *One way to turn
mere wing drop (caused by a stall or near-stall) into a real spin is to use
aileron to try to raise the stalled wing. *This is one of thse disturbing cases
where a pilot's instinctive reaction can kill!

So the adverse yaw on a wing on the verge of a stall will pull the
aircraft into a dangerous spin, when it would have been just a stall.

The slow, draggy aileron will yaw the aircraft like a rudder. *Wing
dihedral will cause the opposite wing to rise into the yaw. *Still,
full ailerons may be applied to counter the roll.

But the aircraft rolls over surprisingly in the direction opposite of
the applied aileron. *This is because of wing dihedral (and inherent
aircraft stability); not because of wing stall, or because the aileron
changes the angle of attack of that wing to cause it to stall. *The
aileron is acting like a rudder to yaw the aircraft. *Dihedral
stability then rolls the aircraft -- oppositely.

But since the aircraft has rolled then the elevator no longer has
gravity (or the inertia of a bank) to push against, so angle of attack
rises rapidly. *Then the wings stall. *The aircraft is in an aerobatic
attitude. *The tail feathers will ensure the nose will then point
down.

The problem with uncoordinated controls and the stall is that, in a
coordinated bank, the elevator pushes 'up' against the COG properly.
* *But when the turn is not coordinated (when the aircraft just rolls
over) then the elevator lift is no longer restrained by the load of
the COG, and can raise the nose of the aircraft rapidly such that the
wings then stall.
* *Slips and skids, however, do not generally cause the plane to roll..
In those conditions elevator control of the COG is not usually in
doubt.

When an aircraft is slow then a lot of elevator is applied to hold the
nose up. *Other than the flare, this condition is most likely to occur
when doing stalls.
* *It is could also occur during the turn when a pilot has overshot
final from base. *That is the danger point on final. *And the roll
into a spin probably came while using coordinated controls. *The
aircraft just stalled in the turn.
* *It does not typically happen during a level approach while using
crossed controls to skid the aircraft to align with the runway.
(Which students may instinctively do to fine-tune their approach,
which instructors may instinctively hate. *It seems a matter of
pree patjudice.)
--

You're over-thinking this. The only times in a the pattern I'd even
consider uncoordinated flight is a slip -- not a skid -- to lose
altitude, or when landing in a cross wind. If you find yourself
cross controlling, add throttle, get coordinated, tell the tower
you're going around and try again.

If I have to slip to lose altitude it means my planning has been bad
unless the slip was part of the landing plan (that does not often
happen unless the approach end has something intruding on the flight
path, or it's a failed engine landing and I carried some altitude as
insurance on short final.

A competent pilot, from the time he or she is on downwind, until on
the taxiway, will only have to reduce throttle -- he or she should not
have to increase it unless there's an unusual circumstance.

Further, the competent pilot, speaking of ground reference, will not
be aiming for the numbers, but for perhaps a thousand feet from his
(or her) turn off. If you only have to retard the throttle from
downwind to turn off, plan your exit from the active correctly, you're
my kind of pilot.

I have too often seen a 152 touch down on the numbers and taxi 1500
feet to exit the active.

You may be a student pilot, perhaps a 'sophomore'. The literal of that
word means 'wise fool'. There's lots to learn about being a safe
pilot, and it's not all in books.

For example: when this was an active newsgroup a discussion led me to
accept that I should use oxygen above 11,000 feet, especially at
night. It keeps vision better. Something I learned after 2k house of
PIC. Ditto, clearing turns when on the 45 degree entry to downwind.
I have a low winged airplane, an M20J, and there might be a Cessna
below me. As such I tend to fly at pattern altitude from a mile out on
entry leg so I can see who might be descending from above me. If I had
a high wing airplane I would come in higher.

And I fly en route altitudes at nominal less 50 or 75 feet, especially
if VFR, and I consider it bad form to pass directly over a VOR because
too many guys have their auto pilot on and will pass dead center, a
possible meeting grounds.

Other real pilots, add your favorite bits of wisdom, we may learn from
one other.
Or, a 'wise fool' might learn something that could be life saving.