Turn to Final - Keeping Ball Centered

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

"Ken S. Tucker" wrote in news:0f85d04c-1390-4fc4-
:

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.


You're a fjukkwit of the first order, kennie.

And for those of you who don't live in lollipop land and don't already
know, a 2 G turn requires 60 degrees of bank and will raise your stall
speed 40%.


Bertie

I don't think anyone has suggested this, but there is a nearly
universal cure if you find yourself uncomfortably out of a reasonable
approach condition -- simply say to yourself this isn't looking good
enough, go around, and do better the next time.

It's my uneducated opinion that too many perfectly good airplanes get
turned to scrap because pilots continue to commit to an action that
has become untenable. You have a hand on the throttle and it's
important to remember to be ready to push it in if you don't like the
way things are shaping up.

Don't let ego get in the way of good judgement.

In article
,
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.)

1. You can stall with the ball centered -- if the ball is not centered,
you can get a spin more easily when you stall.

2. The stall speed goes up as the square root of the secant (1/cosine)
of the angle of bank.

At:
30 deg: 1.07
45 deg: 1.19
60 deg: 1.41
75 deg: 1.97

--
Remove _'s from email address to talk to me.

Tina wrote in news:874d408e-73e6-4064-8d08-
:

I don't think anyone has suggested this, but there is a nearly
universal cure if you find yourself uncomfortably out of a reasonable
approach condition -- simply say to yourself this isn't looking good
enough, go around, and do better the next time.

It's my uneducated opinion that too many perfectly good airplanes get
turned to scrap because pilots continue to commit to an action that
has become untenable. You have a hand on the throttle and it's
important to remember to be ready to push it in if you don't like the
way things are shaping up.

Absolutely.

Don't let ego get in the way of good judgement.

True again. Sometimes it's not ego, though. A lot of thigs come into play,
especially if conditions are tough. It's a curious thing, the sort of
single-mindedness that often accompanies an accident.


Bertie

Orval Fairbairn wrote in news_r_fairbairn-
:

In article
,
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.)

1. You can stall with the ball centered -- if the ball is not centered,
you can get a spin more easily when you stall.

2. The stall speed goes up as the square root of the secant (1/cosine)
of the angle of bank.


Which is, coincidenatlally, the load on the airplane. Minus the sq root
bit, of course.


At:
30 deg: 1.07
45 deg: 1.19
60 deg: 1.41
75 deg: 1.97

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.

skym wrote:
Thanks for replies. I had meant to address the speed issue since I
knew the stall speed increased with bank. I also kept my speed higher
than normal in the turn because of that. I left it out of the
question, and shouldn't have. Assuming I keep the speed up, is the
centered ball a reliable guide?

A reliable guide for what? It's an indicator of coordination, which
is always a good idea. Your airplane flies more efficiently.

Why does no one distinguish between a level turn (constant acceleration into
the center of the arc, which increases load factor) and the load factor in
which the same angle of bank exists in a descent? When descending you are
moving away from the center of the in the vertical direction which means
less acceleration towards the center in the original plane (geometric).

You can feel the load factor difference in the seat of your pants when
descending, compared to maintaining level flight in a steep bank. I don't
understand how people can claim the load factor is the same descending and
turning for example in a 600 fpm descent.

It is no different than twirling a weight at the end of a string. Takes
more energy to maintain the string at a higher horizontal angle.



2. The stall speed goes up as the square root of the secant (1/cosine)
of the angle of bank.

At:
30 deg: 1.07
45 deg: 1.19
60 deg: 1.41
75 deg: 1.97

writes:
Why does no one distinguish between a level turn (constant acceleration into
the center of the arc, which increases load factor) and the load factor in
which the same angle of bank exists in a descent? When descending you are
moving away from the center of the in the vertical direction which means
less acceleration towards the center in the original plane (geometric).

The center just becomes a line in that case, doesn't it? You end up
with the same centripetal force needed towards that center line in
order to turn.

You can feel the load factor difference in the seat of your pants when
descending, compared to maintaining level flight in a steep bank. I don't
understand how people can claim the load factor is the same descending and
turning for example in a 600 fpm descent.

Nosing over into a descent does temporarily reduce load factor, but as
soon as you're established in a constant descent, you're back at the
same 1g load. Gravity is *acceleration*, not *velocity*.

--
James Carlson, Solaris Networking
Sun Microsystems / 35 Network Drive 71.232W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677