Turn to Final - Keeping Ball Centered

Roy Smith wrote:
In article ,
Dudley Henriques wrote:

skym wrote:
While making a turn to base and final recently, I was aware that I was
going to be wide with my normal turn from downwind through base to
final, so I banked more to keep as close to the runway centerline as
possible. I kept thinking about the infamous and usually fatal stall/
spin by some pilots in this situation, I kept thinking that if I keep
the ball centered, even with a very steep bank, that I would be ok and
not auger in. Some of you instructors and old pros...is this correct?
(Not that I intend to make it a practice.)
Ask your instructor to explain to you what happens to the stall speed in
a LEVEL turn as opposed to the stall speed in an unloaded gliding turn
from base to final.
This is a distinction you should definitely be aware of.

Dudley,

I'm not sure what you mean by "unloaded gliding turn". As long as your
descent rate is constant, the loading in a turn is exactly the same as it
is during level flight. A turn is only unloaded if your descent rate is
increasing, as it is during the second quadrant of a lazy eight. But, most
people don't fly their base-to-final turns like that; they fly them at a
(more or less) constant descent rate.

Either that, or I'm mis-understanding what you're trying to say.
The situation I'm describing can occur if you are high as well as wide.
Trading off the altitude by unloading the wings as you turn, you are in
effect doing a gentle last half of a lazy eight, although very shallow.
Unless you can unload the wings by lowering the nose, you are absolutely
correct. Everything is the same g wise. The only reason I mentioned this
is so that he gets squared away on the different scenarios concerning
the base to final turn.
Many students get into a deep fear about base to final turns and bank
thinking all they need to do is increase the bank and they are on the
stall speed increase with g graph. This is true for a level turn and
even a loaded descending turn, but many times on an approach, a pilot
can make the energy tradeoff saving the turn by unloading in the turn
and letting the nose drop scrubbing off some altitude while neutralizing
the bank g increase.


--
Dudley Henriques

Dudley Henriques wrote:

Ask your instructor to explain to you what happens to the stall speed in
a LEVEL turn as opposed to the stall speed in an unloaded gliding turn
from base to final.
This is a distinction you should definitely be aware of.


If he's maintaining a constant rate of descent during the turn there is
no distinction. The load factor decreases only if he is accellerating
towards the ground.

Ron Natalie wrote:
Dudley Henriques wrote:

Ask your instructor to explain to you what happens to the stall speed
in a LEVEL turn as opposed to the stall speed in an unloaded gliding
turn from base to final.
This is a distinction you should definitely be aware of.


If he's maintaining a constant rate of descent during the turn there is
no distinction. The load factor decreases only if he is accellerating
towards the ground.
Exactly. The difference between a loaded turn and simply allowing the
nose to fall through with reduced back pressure.

--
Dudley Henriques

"Dudley Henriques" wrote in message
...
Exactly. The difference between a loaded turn and simply allowing the nose to
fall through with reduced back pressure.

Reducing back pressure is something an inexperienced pilot is instinctively
loath to do when manuvering close to the ground, much more likely to be pulling.

Vaughn

Vaughn Simon wrote:
"Dudley Henriques" wrote in message
...
Exactly. The difference between a loaded turn and simply allowing the nose to
fall through with reduced back pressure.

Reducing back pressure is something an inexperienced pilot is instinctively
loath to do when manuvering close to the ground, much more likely to be pulling.

Vaughn


This is an issue where I have seen evidence on both sides. It is
entirely dependent on the caliber of training a student pilot is
subjected to in the stall curve.
All instructors should be teaching and ingraining in every student they
teach that stall recovery REGARDLESS OF ALTITUDE is entirely dependent
on reducing angle of attack. This is especially true at low altitude
where recovery can be a matter of using every inch of available air
under the airplane to recover.
Instructors should be EMPHASIZING to every student this all important
aspect of a low altitude stall.
By the time an instructor is finished teaching stall recovery to a
student, that student should have the stall recovery habit pattern
BURNED into their very being.......so much in fact that their natural
reaction to ANY stall is to recover by reducing angle of attack so that
the reaction is to do this instead of pulling back.
To accomplish this, instructors have to demonstrate to every student
again and again proper stall recovery using all available means....angle
of attack reduction, coordinated aileron and rudder (for modern GA
airplanes) and power. This should be practiced with emphasis on the
regaining of angle of attack BEFORE initiating recovery. As this
pertains to low altitude recovery, the instructor should emphazize again
and again that recovery in this scenario might very well mean the
lowering of the nose when the raising of the nose is the natural reaction.

Many....many...pilots have been killed outright trying to recover from a
low altitude stall when extending the recovery closer to the ground to
assure regaining of angle of attack was the proper thing to do.

The answer to this issue is in proper training by instructors with the
goal of CHANGING through this training the natural reaction to recover
too early in low altitude stalls.

I consider the imparting of this attitude in a student pilot a critical
aspect of stall recovery training.
I can't emphasize it's importance enough to new instructors.

--
Dudley Henriques

On Mar 13, 9:35*am, "Vaughn Simon"
wrote:
"Dudley Henriques" wrote in message

...

Exactly. The difference between a loaded turn and simply allowing the nose to
fall through with reduced back pressure.

* *Reducing back pressure is something an inexperienced pilot is instinctively
loath to do when manuvering close to the ground, much more likely to be pulling.

on the contrary I have a habit of deliberately pushing forward on the
yoke as I turn onto final, it comes from a fear of stalling and the
fact
that being at this stage of the landing procedure I want my attention
focused outside the cockpit to ensure I line up out of the turn on the
runway centerline, and not worrying about my airspeed.
Terry

On Mar 11, 7:23 pm, skym wrote:
While making a turn to base and final recently, I was aware that I was
going to be wide with my normal turn from downwind through base to
final, so I banked more to keep as close to the runway centerline as
possible. I kept thinking about the infamous and usually fatal stall/
spin by some pilots in this situation, I kept thinking that if I keep
the ball centered, even with a very steep bank, that I would be ok and
not auger in. Some of you instructors and old pros...is this correct?
(Not that I intend to make it a practice.)

Depends on the A/C, what were you flying?
In an F-4 doing a 3-4g bank is easy, but in
a trainer I'd suggest 2g max.
Ken

The absolute best way to find out what will happen is to take an
instructor and go out and do steep turns until you stall it...
Obviously, with adequate altitude...

One of the things you will find is that it is down right hard to stall
the plane in a coordinated turn at a normal approach speed... You will
need to have the yoke back into your gut and ignore all the G's and
the complaining and shaking the airframe will be making... Now, that
isn't to say you can't stall it, but you will have to be blind and
deaf and have a numb butt to do it accidentally...

The other thing you will find is that it is easier to do it in an
uncoordinated turn, but it still takes determination and ignoring the
airframe shaking like a wet dog...

"So, how did Harry Dumbass manage to ignore this and kill himself and
his passengers by turning his fork tailed doctor killer into a lawn
dart?", you ask...
Ahh, I'm glad you asked that...
Ya see, Harry is both high because he is in close and about to over
run the centerline because he is in close... So, being a hotshot
pilot, he chops the throttle, rolls into a hard bank, and stands on
the bottom rudder... About halfway around he realizes his descent rate
has gone off the peg and he is now going to be way short - so he
solves that by pulling the nose up!

Close your eyes and picture it...
The bottom wing snap stalls without so much as a warning shudder
(because the horizontal stab is still flying) , they whip over
inverted, and it is all over but the screaming...

denny

On Mar 12, 2:18 am, "Ken S. Tucker" wrote:

-- IGNORE BELOW --
Depends on the A/C, what were you flying?
In an F-4 doing a 3-4g bank is easy, but in
a trainer I'd suggest 2g max.
Ken
-- IGNORE ABOVE ---

Assuming you're not flying an F-4 in a sim, we'll move on to
reality....

This fear is (correctly) pounded into every aspiring/training pilot --
don't cross control stall on turn to final!

And that's that.

So -- pilots being the life loving critters that they are, add "a
little more speed" as a "buffer." Because we all know we can't stall
at X speed, right?

And then we turn onto final 10-15-20 knots faster than required and
then wonder why 3,500' strip is just barely big enough.

So we'll assume you still need three things:

1) A correct understanding of stall

2) A consistent, safe procedure for the pattern in the airplane you're
flying

3) Demonstrations by a CFI of the sensations and perceptions of the
event prior to and just at the stall in the various possible
circumstances (turn to final being one).

For (1) you need to get into your head that stalls -- while often
described in terms of speed -- are a function of angle of attack. The
wing (or a portion) can't fly anymore because the flow of air below
and above isn't working as designed (I'm sure you've seen the pictures
of burbling air over the wing).

This can be demonstrated on the ground by a CFI with a model airplane.
Then he/she should take you out and demonstrate this in an appropriate
airplane.

For (2), you need to fly patterns at altitude and figure out the
optimal Power (1500 RPM?), Attitude (Nose about there, trim to there),
and configuration (gear down, flaps full, etc) for your airplane at
the speeds you will be flying in the pattern. And then (with your
CFI), explore the left side of the envelope (slower). What you will
find is that in normal 30 degree banks (which you were taught to use
in the pattern), with coordinated turns the airplane continues to fly
quite well 30% over stall speed (1.3 Vso).

Does this mean you will drop out of the sky if a gusts catches you and
momentarily disturbs coordination? No. The airplanes we fly
(especially trainers) are very forgiving in this regard. But keep in
mind "momentarily." You should catch it and fix it.

For (3), he/she should take you to altitude and show you how much
cross control you need to apply to get the airplane to stall. This
should ease your mind a bit, but also ingrain a sense of "This isn't
good" should you place yourself in that predicament later on.

Finally (not on the list but its early), you should practice short
field landings often. I'll probably catch flak on this, but one of the
biggest problems you will see at any airport on a nice day is small
airplanes coming in Way Too Fast.

You will know this by watching the approach from a spot on the ground
-- the patterns are enormous (2 miles or more from the runway) and the
airplane touches down 1/3-1/2 way down the runway and rolls a long,
long way.

I think (IMHO) this is due to the same understanding you have -- "I
might stall due to low speed, so a bit more will give me a buffer to
keep me from that unwelcome event."

Get some more training in stalls and flight at the low end of the
speed regime and join the ranks of safe, educated pilots.


Dan

On Mar 12, 3:39 am, Dan wrote:
On Mar 12, 2:18 am, "Ken S. Tucker" wrote:

-- IGNORE BELOW -- Depends on the A/C, what were you flying?
In an F-4 doing a 3-4g bank is easy, but in
a trainer I'd suggest 2g max.
Ken

-- IGNORE ABOVE ---

Assuming you're not flying an F-4 in a sim, we'll move on to
reality....

This fear is (correctly) pounded into every aspiring/training pilot --
don't cross control stall on turn to final!

A pilot is trained to do 2g coordinated turns,
even in twink flying, gee I wonder why.
It's a perfectly safe thing to do and IIRC was
a requirement for a pilot's license.
Ken
[snip, I have no comment]