Coordinated turns and the little ball

[Mxsmanic]

How much of a movement in the little ball in the turn indicator
corresponds to something you can feel in a real aircraft? And how
much of a movement represents an error large enough to affect flight
safety or proper maneuvering?

--
Transpose mxsmanic and gmail to reach me by e-mail.

[ktbr]

Mxsmanic wrote:
> How much of a movement in the little ball in the turn indicator
> corresponds to something you can feel in a real aircraft? And how
> much of a movement represents an error large enough to affect flight
> safety or proper maneuvering?
>

The answer is that it depends. It is more important to keep the
plane coordinated at slower airspeeds and/or higher load factors.

It is also important on climbout (high angle of attack & large P
factor) because you want the best climb capability you can get
especially with underpowered aircraft. Needless to say it is well
to keep it coordinated in cruise as well since drag is greatly
incresed thus reducing cruise efficiency.

An experienced pilot can feel it when the aircraft is not
flying coordinated. If you were a passenger with a drink sitting
on a table in the back you would notice un-coordinated flight
because the liquid would not be level in the glass.

[Neil Gould]

Recently, Mxsmanic > posted:

> How much of a movement in the little ball in the turn indicator
> corresponds to something you can feel in a real aircraft? And how
> much of a movement represents an error large enough to affect flight
> safety or proper maneuvering?
>
All of this depends on what you're doing at the time. One can slip fairly
drastically -- with the ball pretty far off center -- without much of a
physical sensation. OTOH, one can pin the passenger against the wall with
the same amount of slip. How dangerous any of this is also depends on what
you're doing at the time. If you're careless and go into a stall, then
it's possible that you'll wind up in a spin, which if you're close to the
ground can kill you. The bottom line is that if the pilot is in control of
the aircraft, all of this can be quite safe and routine.

Neil

[Robert M. Gary]

I'm a flight instructor so I can feel 1/4 of a ball out, but that's
what I'm trained to do. However, in your simulator, I would not worry
about it. You're not going to be able to reproduce the environment
similar to the aircraft without having rudders, etc. When I play MSFS I
set it to autocoordination.

-Robert, CFII

Mxsmanic wrote:
> How much of a movement in the little ball in the turn indicator
> corresponds to something you can feel in a real aircraft? And how
> much of a movement represents an error large enough to affect flight
> safety or proper maneuvering?
>
> --
> Transpose mxsmanic and gmail to reach me by e-mail.

[Don Tuite]

On Fri, 06 Oct 2006 15:04:36 GMT, "Neil Gould"
> wrote:

>Recently, Mxsmanic > posted:
>
>> How much of a movement in the little ball in the turn indicator
>> corresponds to something you can feel in a real aircraft? And how
>> much of a movement represents an error large enough to affect flight
>> safety or proper maneuvering?
>>
>All of this depends on what you're doing at the time. One can slip fairly
>drastically -- with the ball pretty far off center -- without much of a
>physical sensation. OTOH, one can pin the passenger against the wall with
>the same amount of slip. How dangerous any of this is also depends on what
>you're doing at the time. If you're careless and go into a stall, then
>it's possible that you'll wind up in a spin, which if you're close to the
>ground can kill you. The bottom line is that if the pilot is in control of
>the aircraft, all of this can be quite safe and routine.
>
Read Kershner on cross-control stalls on the base to final leg.

Even novice passengers can feel uncoordinated flight, but they won't
know why they feel queasy.

Don

[Tony Cox]

"Mxsmanic" > wrote in message
...
>
> How much of a movement in the little ball in the turn indicator
> corresponds to something you can feel in a real aircraft?

Pretty much everyone can sense large deflections -- they'll
feel as they're being pushed to one side of the plane. The
more experienced you are, the smaller movements you can
detect without looking.

> And how
> much of a movement represents an error large enough to affect flight
> safety or proper maneuvering?

It is considered to be good style, and it is generally more
efficient, to maintain coordinated flight in most situations.
Better for passengers & easier not to spill your drink.
But in a slip -- used to deliberately increase air resistance
when you are too fast or too high, or to align the plane with
the runway in a crosswind landing -- the plane will be
uncoordinated on purpose; the ball on the inside of the turn
doesn't indicate "an error" at all, nor does it make the
flight any less safe.

A skid -- which doesn't have any purpose outside of
training AFAIK -- is more problematic. This tends to be a
issue on base-final turns when pilots are tempted to use
too much rudder to tighten up the turn if they've
underestimated wind drift or otherwise miscalculated. When
you are in a turn, the inside wing is always moving through
the air a bit slower than the outside wing and so is closer
to stalling. A skidding turn increases this airspeed difference,
and if you're too slow turning base to final, the danger is that
it'll make it more likely that the inside wing will stall and start
a spin. Just where the ball might be when this happens would
depend on your airspeed, so there's no simple "red line" beyond
which you can't push the ball if that's what you're looking for.

[Peter Duniho]

"T o d d P a t t i s t" > wrote in message
...
> I'm a flight instructor, too, and I don't think I can detect
> steady 1/4 ball out, but I *can* detect when we're
> coordinated and the student suddenly uses inappropriate
> rudder, either too much or too little. It's much easier to
> detect changes than to detect where the ball is. [...]

It's almost as if your body is especially good at detecting acceleration or
something.

:)

[Dudley Henriques]

You're right. The best yaw indicator in the airplane is the nose of the
airplane. Instructors should be able to pick up the slightest amount of
uncoordination simply by watching the nose. Its also a good idea to wean the
student off the ball and onto the nose as soon as possible. I'll go so far
as to say that it was my common practice to do this on the first flight.
In my opinion, much too much attention is placed on the ball as a
coordination verification tool, and much too little attention paid to the
nose of the airplane by a great many CFI's.
Its a choice I know, but I've been teaching this way for a very long time,
and have found it the optimum method for teaching coordination to a new
student.
I will also say that in flying advanced acro, I don't even look at a ball.
At low altitudes in demonstration work, you don't have the time or the
luxury of referencing the ball. You reference the nose of the airplane. Its
the best "ball" you'll ever have.
Dudley Henriques

"T o d d P a t t i s t" > wrote in message
...
> "Robert M. Gary" > wrote:
>
>>I'm a flight instructor so I can feel 1/4 of a ball out,
>
> I'm a flight instructor, too, and I don't think I can detect
> steady 1/4 ball out, but I *can* detect when we're
> coordinated and the student suddenly uses inappropriate
> rudder, either too much or too little. It's much easier to
> detect changes than to detect where the ball is. When the
> student is steady, your butt is sitting steady on the seat.
> As soon as the amount of coordination or uncoordination
> changes, the pressures change and you can feel it. The
> change in pressure on my butt is what signals me to look at
> the ball (or yawstring in the case of a glider) to see how
> far it's going to move. Often I feel that signal before it
> has changed much at all.
> --
> Rule books are paper - they will not cushion a sudden meeting of stone and
> metal.
>
> - Ernest K. Gann, 'Fate is the Hunter.'

[Mxsmanic]

ktbr writes:

> The answer is that it depends. It is more important to keep the
> plane coordinated at slower airspeeds and/or higher load factors.

Is it possible to spot an uncoordinated turn visually, just by
watching how things move out the window, or is it only perceptible
through the movement of the aircraft?

I'm trying to figure out how hard I should try to keep the ball
centered. In the sim I can't feel any movement, so I don't know how
tightly I have to control the turn (based on what the ball says).

> It is also important on climbout (high angle of attack & large P
> factor) because you want the best climb capability you can get
> especially with underpowered aircraft. Needless to say it is well
> to keep it coordinated in cruise as well since drag is greatly
> incresed thus reducing cruise efficiency.

I note that rudder can keep the turn coordinated, but changes in pitch
seem to be able to do it, too. Pulling back on the stick in a turn
not only maintains altitude, but it also seems to coordinate the turn
to some degree.

> An experienced pilot can feel it when the aircraft is not
> flying coordinated. If you were a passenger with a drink sitting
> on a table in the back you would notice un-coordinated flight
> because the liquid would not be level in the glass.

I've seen videos of pilots rolling an aircraft while pouring drinks.
I haven't tried that in the sim.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Neil Gould writes:

> All of this depends on what you're doing at the time. One can slip fairly
> drastically -- with the ball pretty far off center -- without much of a
> physical sensation. OTOH, one can pin the passenger against the wall with
> the same amount of slip.

What distinguishes the two types of slip?

> How dangerous any of this is also depends on what
> you're doing at the time. If you're careless and go into a stall, then
> it's possible that you'll wind up in a spin, which if you're close to the
> ground can kill you. The bottom line is that if the pilot is in control of
> the aircraft, all of this can be quite safe and routine.

The rudder is controlled in my sim by twisting the stick (not very
realistic, but inexpensive), and it's difficult to keep the ball
centered that way. I'm slowly getting better at it, though.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Robert M. Gary writes:

> I'm a flight instructor so I can feel 1/4 of a ball out, but that's
> what I'm trained to do. However, in your simulator, I would not worry
> about it. You're not going to be able to reproduce the environment
> similar to the aircraft without having rudders, etc. When I play MSFS I
> set it to autocoordination.

I have independent rudder enabled and the stick can be twisted to move
the rudder independently, but it's quite hard to precisely control the
rudder this way. Even so, I don't want to just ignore the rudder
completely. I'm doing okay in using rudder to stay aligned on runways
and to land in very modest crosswinds, but keeping a turn coordinated
is challenging (in part because you're moving the stick in several
different ways at once).

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Dudley Henriques writes:

> You're right. The best yaw indicator in the airplane is the nose of the
> airplane. Instructors should be able to pick up the slightest amount of
> uncoordination simply by watching the nose. Its also a good idea to wean the
> student off the ball and onto the nose as soon as possible. I'll go so far
> as to say that it was my common practice to do this on the first flight.
> In my opinion, much too much attention is placed on the ball as a
> coordination verification tool, and much too little attention paid to the
> nose of the airplane by a great many CFI's.

How can I determine that the turn is uncoordinated by looking at the
way the nose moves?

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Tony Cox writes:

> Pretty much everyone can sense large deflections -- they'll
> feel as they're being pushed to one side of the plane. The
> more experienced you are, the smaller movements you can
> detect without looking.

Is this the movement that makes people sick? From your description it
sounds like the turning of a car (which usually doesn't make people
sick, unless the car is really turning back and forth a lot).

> It is considered to be good style, and it is generally more
> efficient, to maintain coordinated flight in most situations.

Is it possible to do a coordinated turn by adjusting pitch and roll at
the same time, without the use of the rudder?

Do autopilots use the rudder to maintain coordinated turns?

> Better for passengers & easier not to spill your drink.
> But in a slip -- used to deliberately increase air resistance
> when you are too fast or too high, or to align the plane with
> the runway in a crosswind landing -- the plane will be
> uncoordinated on purpose; the ball on the inside of the turn
> doesn't indicate "an error" at all, nor does it make the
> flight any less safe.

I regularly forget the difference between a skid and a slip.

> A skid -- which doesn't have any purpose outside of
> training AFAIK -- is more problematic. This tends to be a
> issue on base-final turns when pilots are tempted to use
> too much rudder to tighten up the turn if they've
> underestimated wind drift or otherwise miscalculated. When
> you are in a turn, the inside wing is always moving through
> the air a bit slower than the outside wing and so is closer
> to stalling. A skidding turn increases this airspeed difference,
> and if you're too slow turning base to final, the danger is that
> it'll make it more likely that the inside wing will stall and start
> a spin. Just where the ball might be when this happens would
> depend on your airspeed, so there's no simple "red line" beyond
> which you can't push the ball if that's what you're looking for.

I'm just trying to figure out how closely I should try to keep it
aligned, since I have no physical movements to provide clues.

I've been trying not to resort to rudder alone for runway alignment.
I'm still not very good at alignment except when coming straight in
from a great distance away, with no wind. Just keeping the aircraft
on the runway during landing is a challenge. I don't usually turn off
the wind, though, because I figure that in real life, dead calm wind
is the exception to the rule.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Jose[_1_]]

> The best yaw indicator in the airplane is the nose of the
> airplane.

How do you read it?

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[Dudley Henriques]

"Jose" > wrote in message
...
>> The best yaw indicator in the airplane is the nose of the airplane.
>
> How do you read it?

You eyeball it.
The nose will pin entering into and out of a turn if the exact amount of
complimentary rudder pressure for the amount of aileron displacement is
being used. The nose will either lead or lag the turn entry or exit (slip or
skid) if the amount of rudder in play is excessive or inadequate for the
amount of aileron pressure in play. A good pilot will watch the nose
entering into and out of turns watching for this "pinning". The pin won't
stay there long, but long enough to establish control pressure application
quality.
As an extreme example of how this visual cue is used by many demonstration
pilots; in a low altitude slow roll entry, you naturally need inside rudder
with initial aileron displacement to offset adverse yaw as in any turn
entry. But at low altitude, in a slow roll entry, you absolutely can't pull
the nose down which is exactly what you will do if that inside rudder is
held in too long. In other words, what you want in this situation is NOT to
pin the nose. The problem isn't that the nose pin is wrong. The problem is
that it's not a turn entry, but a slow roll entry, and to boot, its a slow
roll entry at low altitude. Where you would be neutralizing the lateral
stick while blending in an increase in angle of attack for the split lift
vector found in a normal turn, in the slow roll scenario, you are going to
need a rudder switch to top rudder to keep the nose up as the airplane rolls
to the knife edge position.
What I'm getting at here isn't a lesson in low altitude rolls. What I'm
stressing is the absolute need in this situation to know what's happening
with the airplane based on visual cues ONLY! This means NO BALL!!
Actually, in the slow roll scenario, you USE that adverse yaw to your
advantage by ALLOWING it to happen. Again, its a visual cue, NOT an
instrument cue. You look at the panel at all in the low altitude scenario
and you won't have to worry about dinner, because you won't be there!
Visual cues on the nose again; only this time you're using adverse yaw
instead of fighting it. Rolling left, instead of stopping the right yaw, you
allow it. You watch the nose carefully.
As you roll left without left rudder, the nose will swing right and up. You
watch the nose and play that against the left aileron pressure you're
applying. As the roll progresses, you simply follow the adverse yaw with
RIGHT RUDDER to keep the nose up.
What I'm describing here is simply the entry into the roll. Once the roll is
established, the rest is standard procedure for a slow roll.
So how does this apply to giving primary instruction?
In my opinion, getting the student out of the panel (the ball) and into
watching the nose during initial training is extremely beneficial. With
practice using the nose of the airplane as the primary reference and visual
cue in verifying control coordination actually becomes second nature, and
once accomplished, becomes an ingrained habit that follows a pilot
throughout his/her career.
Bottom line on all this......a pilot thoroughly acclimated from the very
beginning to using the nose of the aircraft as a ball will detect and
reflexively correct any deviation from coordinated flight no matter how
slight. Correct rudder use should become second nature to a pilot trained in
this fashion.
Dudley Henriques

[Stefan]

Dudley Henriques schrieb:

> The nose will pin entering into and out of a turn if the exact amount of
> complimentary rudder pressure for the amount of aileron displacement is
> being used.

Once the turn is established and sustained, I see no way to check
coordination by looking at the nose.

Stefan

[Stefan]

Mxsmanic schrieb:

> Is it possible to spot an uncoordinated turn visually, just by
> watching how things move out the window, or is it only perceptible
> through the movement of the aircraft?

In a sustained turn, you can't see it. But you can feel it. In a real
aircraft, that is.

> I'm trying to figure out how hard I should try to keep the ball
> centered.

It's goot piloting to keep the ball centered. Always work on your skills
to keep the ball even more centered. Actually, the ball is a pretty
coarse instument. So if the ball moves out of the center even by a
detectable amount, you are flying really uncoordinated.

> I note that rudder can keep the turn coordinated, but changes in pitch
> seem to be able to do it, too. Pulling back on the stick in a turn
> not only maintains altitude, but it also seems to coordinate the turn
> to some degree.

"To some degree" is not good enough. It may be good enough from a
strictly practical point of view, but it's bad style.

> I've seen videos of pilots rolling an aircraft while pouring drinks.
> I haven't tried that in the sim.

Shouldn't be very difficult while playing MSFS...

Stefan

[mike regish]

I think he'll still pour the drink all over himself...:-)

mike

"Stefan" > wrote in message
...
>
>> I've seen videos of pilots rolling an aircraft while pouring drinks.
>> I haven't tried that in the sim.
>
> Shouldn't be very difficult while playing MSFS...
>
> Stefan

[Dudley Henriques]

"Stefan" > wrote in message
...
> Dudley Henriques schrieb:
>
>> The nose will pin entering into and out of a turn if the exact amount of
>> complimentary rudder pressure for the amount of aileron displacement is
>> being used.
>
> Once the turn is established and sustained, I see no way to check
> coordination by looking at the nose.
>
> Stefan

Copied from the post you are answering;

"The pin won't stay there long, but long enough to establish control
pressure application
quality."

Dudley Henriques

[Stefan]

Dudley Henriques schrieb:

>> Once the turn is established and sustained, I see no way to check
>> coordination by looking at the nose.

> "The pin won't stay there long, but long enough to establish control
> pressure application
> quality."

When starting the turn, you roll, which means you apply ailerons. When
the turn is established, you don't apply ailerons anymore (how much
exactly depends on the aircraft, some even require outwards ailerons to
prevent overbanking). Hence the "pressure application quality" you
establish at the beginning of the turn doesn't do you any good to stay
coordinaed once the turn is established.

Stefan

[Dudley Henriques]

"Dudley Henriques" > wrote in message
...
>
> "Stefan" > wrote in message
> ...
>> Dudley Henriques schrieb:
>>
>>> The nose will pin entering into and out of a turn if the exact amount of
>>> complimentary rudder pressure for the amount of aileron displacement is
>>> being used.
>>
>> Once the turn is established and sustained, I see no way to check
>> coordination by looking at the nose.
>>
>> Stefan
>
> Copied from the post you are answering;
>
> "The pin won't stay there long, but long enough to establish control
> pressure application
> quality."
>
> Dudley Henriques

Let me add to this, that once stabilized in the turn, it is not only
possible, but advisable to monitor coordination by using physical cues
instead of watching the ball. The quality of that physical monitoring will
include a visual cue on the nose, and the physical cues sensed by the body.
The overall quality of this process will be dictated by experience. Just
because the controls have been neutralized in a stable turn doesn't mean
slip and skid are not noticeable. A good pilot will pick up on an out of
doghouse ball with no trouble at all.
Its for this reason that getting students off the ball and outside the
airplane is prime early on in flight training.
Its important to note here as well, considering the totally incorrect input
I've been seeing lately on these forums by a specific poster, that there is
a HUGE....and I'll repeat this for clarity ...HUGE difference between the
way a plane is flown in VERY conditions, and when on the gauges. The very
essence of attitude instrument training is in teaching the pilot to make
this transition from using physical sensing to NOT using physical sensing.
Finally; you teach people to fly airplanes using physical and visual cues.
This doesn't mean that instruments are not useful and shouldn't be used
while flying using these cues.
It does mean however that over concentration on using a ball for
coordination quality at the expense of stressing outside references can
deter from a student's development of the necessary physical cues needed to
become a good pilot.
Pilots need go no further in verifying the validity of what I have said here
than approaching the next airshow demonstration pilot they meet and asking
them,
"Do you check your ball even ONCE while performing?"
I already know the answer to this question :-))
Dudley Henriques

[Dudley Henriques]

"Stefan" > wrote in message
...
> Dudley Henriques schrieb:
>
>>> Once the turn is established and sustained, I see no way to check
>>> coordination by looking at the nose.
>
>> "The pin won't stay there long, but long enough to establish control
>> pressure application
>> quality."
>
> When starting the turn, you roll, which means you apply ailerons. When the
> turn is established, you don't apply ailerons anymore (how much exactly
> depends on the aircraft, some even require outwards ailerons to prevent
> overbanking). Hence the "pressure application quality" you establish at
> the beginning of the turn doesn't do you any good to stay coordinaed once
> the turn is established.
>
> Stefan

Its true that once a turn is established, control application becomes
stabilized except for any underbanking or over banking correction needed in
shallow or steep banks.

Although medium turns are more stable than shallow turns and steep turns
where underbanking and overbanking tendency has to be dealt with, if the
airplane has any slip or skid on it, its easily detected using physical and
visual sensing by a well trained pilot.
Dudley Henriques

[Dudley Henriques]

"Dudley Henriques" > wrote in message
...


in VERY conditions, (obviously should read VFR conditions :-)

[Stefan]

Dudley Henriques schrieb:

> if the airplane has any slip or skid on it,
> its easily detected using physical and
> visual sensing by a well trained pilot.

Now please explain me which _visual_ cues tell you an uncoordinated
_sustained_ turn.

Stefan

[Dudley Henriques]

"Stefan" > wrote in message
...
> Dudley Henriques schrieb:
>
>> if the airplane has any slip or skid on it, its easily detected using
>> physical and visual sensing by a well trained pilot.
>
> Now please explain me which _visual_ cues tell you an uncoordinated
> _sustained_ turn.
>
> Stefan

I can see by the "Now please explain to me" opening that I don't really
want to deal with this any further with you.
Lets just say that we have a difference of opinion and be done with it.
Happens all the time on Usenet :-)
Best to you,
Dudley Henriques

[Stefan]

Dudley Henriques schrieb:

> I can see by the "Now please explain to me" opening that I don't really
> want to deal with this any further with you.
> Lets just say that we have a difference of opinion and be done with it.

I don't have any opinion on this at all. I just don't see which _visual_
clue could tell me that a sustained turn is uncoordinated. I was looking
forward to learn something new. Unfortunately you don't want me to learn
something new.

I wonder whether you told your students that you didn't want to deal
with them anymore, too, when they dared to ask.

Stefan

[Roy Smith]

In article >,
"Dudley Henriques" > wrote:

> You're right. The best yaw indicator in the airplane is the nose of the
> airplane. Instructors should be able to pick up the slightest amount of
> uncoordination simply by watching the nose.

An interesting demo is to take you feet off the rudders, look out over the
nose, and quickly roll in full left or right aileron deflection. Depending
on how much inverse yaw your particular plane has (172's do a great demo;
Cherokees less so), you will see the nose of the plane first get pulled off
to the *outside* of the turn, then as the bank angle gets established,
start to get dragged in the right direction.

[Dudley Henriques]

"Stefan" > wrote in message
. ..
> Dudley Henriques schrieb:
>
>> I can see by the "Now please explain to me" opening that I don't really
>> want to deal with this any further with you.
>> Lets just say that we have a difference of opinion and be done with it.
>
> I don't have any opinion on this at all. I just don't see which _visual_
> clue could tell me that a sustained turn is uncoordinated. I was looking
> forward to learn something new. Unfortunately you don't want me to learn
> something new.
>
> I wonder whether you told your students that you didn't want to deal with
> them anymore, too, when they dared to ask.
>
> Stefan

I learned a long time ago on Usenet, that if someone wants to learn
something, or even exchange a friendly dialog with someone that they might
disagree with, they don't open that "request for learning" with the phrase
"Now you tell me..........". There was a time when I would take on those who
approach me in this way, but I'm mellowing in my old age I guess. To tell
you the honest truth, I just don't care for these "engagements"any longer.
I simply avoid posters who do this with me.
As if I needed any further indication that my judgment is correct on this,
simply reference your own post above and your unsolicited responses to what
I have said.
Starting with your first post, rather than asking a question, which I assume
goes along with your "request to learn something", your posts to me have
been statements in direct opposition to what I have said. You clearly
believe that it is I who have something to learn and not you :-)
Now with this last post, you have become aggressive and accusatory.
Clearly I was right to not wish to engage you, and I will take your totally
unnecessary comment about how I might or might not have treated my students
under advisement from a bit more competent authority on the subject :-)))
Anyway, no hard feelings, and all the very best to you.
Dudley Henriques

[Dudley Henriques]

"Roy Smith" > wrote in message
...
> In article >,
> "Dudley Henriques" > wrote:
>
>> You're right. The best yaw indicator in the airplane is the nose of the
>> airplane. Instructors should be able to pick up the slightest amount of
>> uncoordination simply by watching the nose.
>
> An interesting demo is to take you feet off the rudders, look out over the
> nose, and quickly roll in full left or right aileron deflection.
> Depending
> on how much inverse yaw your particular plane has (172's do a great demo;
> Cherokees less so), you will see the nose of the plane first get pulled
> off
> to the *outside* of the turn, then as the bank angle gets established,
> start to get dragged in the right direction.

Exactly!

Dudley

[Mxsmanic]

Roy Smith writes:

> An interesting demo is to take you feet off the rudders, look out over the
> nose, and quickly roll in full left or right aileron deflection. Depending
> on how much inverse yaw your particular plane has (172's do a great demo;
> Cherokees less so), you will see the nose of the plane first get pulled off
> to the *outside* of the turn, then as the bank angle gets established,
> start to get dragged in the right direction.

So for a turn to the right, the passengers are first shifted to the
right, and then to the left?

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Jose[_1_]]

> if the
> airplane has any slip or skid on it, its easily detected using physical and
> visual sensing by a well trained pilot.

What should one look for?

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[Dudley Henriques]

"Jose" > wrote in message
et...
>> if the airplane has any slip or skid on it, its easily detected using
>> physical and visual sensing by a well trained pilot.
>
> What should one look for?

Its not something that's cut and dried that you can point to and say, "this
is it". The ability to determine coordination comes through experience. The
cues are quite subtle actually. They involve sight ( the lead or lag of the
nose vs the control rate input for starters). This couples with your "seat
of the pants" sensing for whether or not the tail is lined up with the
airplane.
Its all related to cues. We can all do this, and do it without thinking
about it all the time, but exactly how good we are at doing it is another
matter.
You develop this ability over time through experience. If an instructor
keeps a student on the ball for example, instead of getting the student
outside the airplane and acclimated to watching the nose and "feeling" the
airplane, this acute sensing takes much longer to develop.
I've noticed through the years when introducing licensed pilots to
aerobatics for the first time, that those who had learned to fly in very
basic airplanes like J3's or Cessna 150's with a primary panel seemed to
have a better handle on what the airplane was actually doing. These pilots
without question flew the airplane using outside references much more than
pilots coming to me from a background where their instructors had
verification of their basic flying referencing the ball on the panel.
Its not a big deal really, and most pilots can do just fine either way. I do
believe however, that using outside references early on in training has
great benefit down the line and have stressed this method all through my
career in aviation.
Its when you get into specialized flying like aerobatics, power line and
game patrol, and especially Ag flying, where the flying of the airplane has
to be second nature as opposed to constant verification through the panel of
what's going on where learning to fly this way pays for itself.
Certainly in low altitude aerobatic demonstration work flying this way is
mandatory. I will tell you flatly and without question that when doing
airshow work, aside from monitoring engine parameters during reversals, I
wouldn't even THINK of referencing a ball on my panel to verify that I was
coordinated. In fact, many acro pilots will actually take the turn and bank
out of the airplane altogether to save the weight of the system.
All this doesn't mean that an instructor should neglect an integrated method
of flight instruction where visual referencing outside the airplane and the
instrument counterpart is taught. It just means that instructors are well
advised to stress outside visual references early on so that the ability to
develop the skill to use these references properly begins to form.
Dudley Henriques

[Stefan]

Dudley Henriques schrieb:

> I learned a long time ago on Usenet, that if someone wants to learn
> something, or even exchange a friendly dialog with someone that they might
> disagree with, they don't open that "request for learning" with the phrase
> "Now you tell me..........".

And I learned a long time ago, and not on Usenet, that changing the
subject and accusing others to have become aggressive instead of
answering a question is a very common way of packpedaling.

> As if I needed any further indication that my judgment is correct on this,

Oh no, you need not, beware! How could I dare to ask. I bow to your
infallibility.

Stefan

[Dudley Henriques]

"Stefan" > wrote in message
...
> Dudley Henriques schrieb:
>
>> I learned a long time ago on Usenet, that if someone wants to learn
>> something, or even exchange a friendly dialog with someone that they
>> might disagree with, they don't open that "request for learning" with the
>> phrase "Now you tell me..........".
>
> And I learned a long time ago, and not on Usenet, that changing the
> subject and accusing others to have become aggressive instead of answering
> a question is a very common way of packpedaling.
>
>> As if I needed any further indication that my judgment is correct on
>> this,
>
> Oh no, you need not, beware! How could I dare to ask. I bow to your
> infallibility.
>
> Stefan

No problem. Take care.
Dudley Henriques

[new_CFI]

Roy Smith > wrote in
:

> In article >,
> "Dudley Henriques" > wrote:
>
>> You're right. The best yaw indicator in the airplane is the nose of
>> the airplane. Instructors should be able to pick up the slightest
>> amount of uncoordination simply by watching the nose.
>
> An interesting demo is to take you feet off the rudders, look out over
> the nose, and quickly roll in full left or right aileron deflection.
> Depending on how much inverse yaw your particular plane has (172's do
> a great demo; Cherokees less so), you will see the nose of the plane
> first get pulled off to the *outside* of the turn, then as the bank
> angle gets established, start to get dragged in the right direction.
>

I had an instructor demonstrate this without and with rudder. It was a
good example of look and feel. Its almost as if without rudder its the
airplane that moves....and with rudder the world moves, not the plane.

[Dudley Henriques]

"new_CFI" > wrote in message
...
> Roy Smith > wrote in
> :
>
>> In article >,
>> "Dudley Henriques" > wrote:
> I had an instructor demonstrate this without and with rudder. It was a
> good example of look and feel. Its almost as if without rudder its the
> airplane that moves....and with rudder the world moves, not the plane.

As you get into flying extremely high performance airplanes like the T38
Talon for example, rudder actually becomes moot. You can fly the T38,
(including aerobatics) all day long with your feet flat on the floor of the
tunnels.
Rudder applied while rolling a T38 at certain lateral deflections above 1 g
can actually couple the airplane and then be followed immediately by a
departure from controlled flight.
Dudley Henriques

[Jose[_1_]]

> Rudder applied while rolling a T38 at certain lateral deflections above 1 g
> can actually couple the airplane and then be followed immediately by a
> departure from controlled flight.

What does "couple" mean in this context?

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[Dudley Henriques]

"Jose" > wrote in message
om...
>> Rudder applied while rolling a T38 at certain lateral deflections above 1
>> g can actually couple the airplane and then be followed immediately by a
>> departure from controlled flight.
>
> What does "couple" mean in this context?

The T38, because of its long mass distribution fuselage vs wings, exhibits a
very small roll inertia in comparison to its pitch and yaw inertia. If the
38 is rolled fast enough at any g above 1g, (with the airplane loaded) you
can couple the roll axis with another inertia axis, usually pitch in the
Talon. Its quite a complex issue, and involves both the inertial axis and
the aerodynamic axis of the aircraft.
The result, if a coupling occurs, is almost always a violent departure.
Its a fun ride in the T2 OCF and spin recovery program at the Naval Test
Pilot School. The T2 is more balanced in mass than the T38, but you can
deliberately couple the T2 and go for the ride of your life......its sort of
like a military Lomchavak :-) In the T38, as it is in all long and slender
high performance airplanes with short stubby wing planforms (The F104 is a
perfect example); its a very serious matter.
Dudley Henriques

[Jose[_1_]]

> If the
> 38 is rolled fast enough at any g above 1g, (with the airplane loaded) you
> can couple the roll axis with another inertia axis, usually pitch in the
> Talon. Its quite a complex issue, and involves both the inertial axis and
> the aerodynamic axis of the aircraft.

Ok, I see it's interesting, but I'm still not sure what it means. Is
"pitch" referenced to the earth or to the (rolling) aircraft axis?

Is it something like "If you are rolling fast, and then stop the roll,
the aircraft will pitch towards the pilot's feet."?

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[Morgans[_2_]]

"Jose" > wrote in message
om...
>> If the 38 is rolled fast enough at any g above 1g, (with the airplane loaded)
>> you can couple the roll axis with another inertia axis, usually pitch in the
>> Talon. Its quite a complex issue, and involves both the inertial axis and the
>> aerodynamic axis of the aircraft.
>
> Ok, I see it's interesting, but I'm still not sure what it means. Is "pitch"
> referenced to the earth or to the (rolling) aircraft axis?

I'm betting it is a motion not unlike a child's spinning top, as it slows down
too much, and starts to wobble on it's axis, right before it really wobbles and
falls down. That is when you depart from controlled flight! <g>

Kinda' right, Dud?
--
Jim in NC

[Dudley Henriques]

"Jose" > wrote in message
om...
>> If the 38 is rolled fast enough at any g above 1g, (with the airplane
>> loaded) you can couple the roll axis with another inertia axis, usually
>> pitch in the Talon. Its quite a complex issue, and involves both the
>> inertial axis and the aerodynamic axis of the aircraft.
>
> Ok, I see it's interesting, but I'm still not sure what it means. Is
> "pitch" referenced to the earth or to the (rolling) aircraft axis?
>
> Is it something like "If you are rolling fast, and then stop the roll, the
> aircraft will pitch towards the pilot's feet."?

Its a complex model. Basically, you can visualize inertia coupling by
splitting the airplane into 2 basic elements of mass; one element
representing the mass in front of the cg and the other behind it.
There are 2 separate axis systems in play for an airplane in maneuvering
flight. The first axis is the is the aerodynamic axis system acting though
the cg in the relative wind direction, and the other is the inertia axis
acting through the cg lined up with the two mass elements I've described.
If you are maneuvering at say 1g or even unloaded where the 2 axis systems
were in alignment, there would be no coupling in a roll.
But if the inertia axis is inclined to the aerodynamic axis for some
reason....say you had a slight pitch input in play as hard aileron was being
applied (the airplane loaded above 1g,)
now you have a condition where the 2 axis systems are not aligned. As roll
input progresses under this condition, a pitch moment can be produced, and
its the coupling of the two axis systems that constitutes an inertia
coupling.
Dudley Henriques

[Dudley Henriques]

Could make for an interesting discussion on the physics forum :-)
I'm not all that up on the physics of spinning tops these days as I'm
getting older and more feeble minded by the day :-), but off the top (no pun
intended) of my head, I'm guessing that as the speed slows on a spinning
top, a mismatch similar to the mismatch between the two axis systems in the
T38 would probably cause a gravitational torque change in the top,
accounting for a precess determined by the torque.
I think you could easily get into angular momentum here :-))
Anyway....I see the main difference between the two examples as the
existence of the aerodynamic axis produced by an extremely predominant
relative wind in the T38 as being missing in the spinning top.
Dudley

"Morgans" > wrote in message
...
>
> "Jose" > wrote in message
> om...
>>> If the 38 is rolled fast enough at any g above 1g, (with the airplane
>>> loaded) you can couple the roll axis with another inertia axis, usually
>>> pitch in the Talon. Its quite a complex issue, and involves both the
>>> inertial axis and the aerodynamic axis of the aircraft.
>>
>> Ok, I see it's interesting, but I'm still not sure what it means. Is
>> "pitch" referenced to the earth or to the (rolling) aircraft axis?
>
> I'm betting it is a motion not unlike a child's spinning top, as it slows
> down too much, and starts to wobble on it's axis, right before it really
> wobbles and falls down. That is when you depart from controlled flight!
> <g>
>
> Kinda' right, Dud?
> --
> Jim in NC

[Jose[_1_]]

> There are 2 separate axis systems in play for an airplane in maneuvering
> flight. The first axis is the is the aerodynamic axis system acting though
> the cg in the relative wind direction, and the other is the inertia axis
> acting through the cg lined up with [front and back] mass elements [...]
> ...if the inertia axis is inclined to the aerodynamic axis for some
> reason [...] the 2 axis systems are not aligned. [...] a pitch moment
> can be produced, and its the coupling [...] that constitutes an inertia
> coupling.

Thanks. That makes it much clearer to me.

If I'm banked, and I "pitch up", does that mean the nose rises up with
respect to the horizon, or with respect to the pilot's feet?

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

[Dudley Henriques]

"Jose" > wrote in message
...
>> There are 2 separate axis systems in play for an airplane in maneuvering
>> flight. The first axis is the is the aerodynamic axis system acting
>> though the cg in the relative wind direction, and the other is the
>> inertia axis acting through the cg lined up with [front and back] mass
>> elements [...]
>> ...if the inertia axis is inclined to the aerodynamic axis for some
>> reason [...] the 2 axis systems are not aligned. [...] a pitch moment
>> can be produced, and its the coupling [...] that constitutes an inertia
>> coupling.
>
> Thanks. That makes it much clearer to me.
>
> If I'm banked, and I "pitch up", does that mean the nose rises up with
> respect to the horizon, or with respect to the pilot's feet?

Pilot's feet. The pitch axis is considered controlled by the elevator or
stabilator as the case may be. Any pressure both positive or negative to the
elevator/stab regardless of the aircraft's position in relation to the
horizon is considered a pitch input.
If you rolled the airplane upside down and applied back pressure, the Split
S would be a pitch input. Rolling into a turn and applying back pressure is
also a pitch input.
Dudley Henriques

[Stefan]

Jose schrieb:

>> Rudder applied while rolling a T38 at certain lateral deflections
>> above 1 g can actually couple the airplane and then be followed
>> immediately by a departure from controlled flight.

> What does "couple" mean in this context?

I guess he means precession. If you roll fast enogh, your aircraft acts
as a gyroscope. Now apply a force perpendicular to the roll axis, and
the result will be a precession motion which can be pretty impressive.

You've probably seen (live on an airshow or canned in a video)
gyroscopic maneuvres flown with propeller driven planes. There, the
propellor is the gyroscope. When your aircraft lacks a propellor, you
can still fly gyroscopic maneuvres. The trick is to roll fast enough and
transform the entire aircraft into a gyroscope. You don't need a high
performance jet for this, it works pretty well with an aerobatic glider
with a sufficient roll rate, too (Fox, Swift).

Very funny stuff, yet completely irrelevant to the average spam can
driver. And I doubt MSFS's aerodynamic model canhandle it.

Stefan

[new_CFI]

>
> I guess he means precession. If you roll fast enogh, your aircraft
> acts as a gyroscope. Now apply a force perpendicular to the roll axis,
> and the result will be a precession motion which can be pretty
impressive.



ok, I knew it must have soemthing to do with a gyro....I couldnt reason it
out...but this makes sence. I hope your right...or else ill just have to
go back to being confused again.

[Dudley Henriques]

"new_CFI" > wrote in message
...
>
>>
>> I guess he means precession. If you roll fast enogh, your aircraft
>> acts as a gyroscope. Now apply a force perpendicular to the roll axis,
>> and the result will be a precession motion which can be pretty
> impressive.
>
>
>
> ok, I knew it must have soemthing to do with a gyro....I couldnt reason it
> out...but this makes sence. I hope your right...or else ill just have to
> go back to being confused again.

That's a shame it makes sense, as its not correct, and understanding all
things related to flying are worth knowing as a flight instructor. There's
really no reason for any instructor to be "confused" when a little research
will enhance understanding.
If you are actually interested in inertia coupling, perhaps a little bit of
research might bring you up to speed on it. If not, please accept my sincere
apology for having mentioned it.
Dudley Henriques

[Walt]

Dudley Henriques wrote:
> "new_CFI" > wrote in message
> ...
> >
> >>
> >> I guess he means precession. If you roll fast enogh, your aircraft
> >> acts as a gyroscope. Now apply a force perpendicular to the roll axis,
> >> and the result will be a precession motion which can be pretty
> > impressive.
> >
> >
> >
> > ok, I knew it must have soemthing to do with a gyro....I couldnt reason it
> > out...but this makes sence. I hope your right...or else ill just have to
> > go back to being confused again.
>
> That's a shame it makes sense, as its not correct, and understanding all
> things related to flying are worth knowing as a flight instructor. There's
> really no reason for any instructor to be "confused" when a little research
> will enhance understanding.
> If you are actually interested in inertia coupling, perhaps a little bit of
> research might bring you up to speed on it. If not, please accept my sincere
> apology for having mentioned it.
> Dudley Henriques

Googling "inertia coupling" I found this, which cleared things up a bit
(at least for me):

A few of the experimental aircraft encountered a new type of behavior
known as inertia coupling, a behavior that was not fully appreciated
until the F-100 and F-102 also encountered it. Inertia coupling
resulted from the tendency of the new generation of high-speed aircraft
to concentrate most of the weight in a long thin fuselage, a departure
from the distribution of subsonic fighters. The X-3 configuration is an
excellent illustration. Even though its high-speed performance was
disappointing, the X-3's unanticipated susceptibility to loss of
control from inertia coupling contributed to understanding the problem.
With much less weight in the wing and tail, the dynamic motion in a
maneuver could cause the inertia of the fuselage to overpower the
aerodynamic stabilizing forces of the wing and tail. In the worst cases
the pilot lost control and the resulting abnormal air loads caused
airframe structural failure. The early F-100A models are remembered as
a classic example of susceptibility to inertia coupling, although the
initial F-102A models also encountered the problem.

--Walt
Bozeman, Montana

[Dudley Henriques]

"Walt" > wrote in message
ups.com...
>
> Dudley Henriques wrote:
>> "new_CFI" > wrote in message
>> ...
>> >
>> >>
>> >> I guess he means precession. If you roll fast enogh, your aircraft
>> >> acts as a gyroscope. Now apply a force perpendicular to the roll axis,
>> >> and the result will be a precession motion which can be pretty
>> > impressive.
>> >
>> >
>> >
>> > ok, I knew it must have soemthing to do with a gyro....I couldnt reason
>> > it
>> > out...but this makes sence. I hope your right...or else ill just have
>> > to
>> > go back to being confused again.
>>
>> That's a shame it makes sense, as its not correct, and understanding all
>> things related to flying are worth knowing as a flight instructor.
>> There's
>> really no reason for any instructor to be "confused" when a little
>> research
>> will enhance understanding.
>> If you are actually interested in inertia coupling, perhaps a little bit
>> of
>> research might bring you up to speed on it. If not, please accept my
>> sincere
>> apology for having mentioned it.
>> Dudley Henriques
>
> Googling "inertia coupling" I found this, which cleared things up a bit
> (at least for me):
>
> A few of the experimental aircraft encountered a new type of behavior
> known as inertia coupling, a behavior that was not fully appreciated
> until the F-100 and F-102 also encountered it. Inertia coupling
> resulted from the tendency of the new generation of high-speed aircraft
> to concentrate most of the weight in a long thin fuselage, a departure
> from the distribution of subsonic fighters. The X-3 configuration is an
> excellent illustration. Even though its high-speed performance was
> disappointing, the X-3's unanticipated susceptibility to loss of
> control from inertia coupling contributed to understanding the problem.
> With much less weight in the wing and tail, the dynamic motion in a
> maneuver could cause the inertia of the fuselage to overpower the
> aerodynamic stabilizing forces of the wing and tail. In the worst cases
> the pilot lost control and the resulting abnormal air loads caused
> airframe structural failure. The early F-100A models are remembered as
> a classic example of susceptibility to inertia coupling, although the
> initial F-102A models also encountered the problem.
>
> --Walt
> Bozeman, Montana

Sounds like a winner to me. Thank you for taking the time and interest.
Dudley Henriques

[Morgans[_2_]]

>> With much less weight in the wing and tail, the dynamic motion in a
>> maneuver could cause the inertia of the fuselage to overpower the
>> aerodynamic stabilizing forces of the wing and tail. In the worst cases
>> the pilot lost control and the resulting abnormal air loads caused
>> airframe structural failure.

> Sounds like a winner to me. Thank you for taking the time and interest.
> Dudley Henriques

I'm not quite sure what that means, as far as what motion the fuselage actually
takes.

Does the nose veer off of the line of flight, or does something else happen?
--
Jim in NC

[Jim Macklin]

Lomcevak Tumble - Aerobatic Maneuver Demonstrations -
Fighter ... Student Air Show Pilot, Carl, gets cockpit
instruction on flying the Lomcemvak tumbling maneuver.
Fighter Combat International lists our Adventure Home ...
www.fightercombat.com/vid_03Sep04.htm - 23k - Cached -
Similar pages


[PDF] Maneuver Name: File Format: PDF/Adobe Acrobat - View
as HTML
Maneuver Description: The 45° Up Lomcevak begins
with an aggressive pull to. the 45° up line "A". Once
established on the 45° up line, the aircraft is ...
www.fightercombat.com/maneuvers/Lomcevak.pdf -
Similar pages


All about aerobatics-Freestyle-torque roll, Knife edge spin,
flat ... There are variations for lomcevak, especialy in the
way to begin (level description lomcevak , 45° description
lomcevak ou vertical description lomcevak ). ...
rafaero.free.fr/voltige4-eng.html - 12k - Cached -
Similar pages


"Morgans" > wrote in message
...
| >> With much less weight in the wing and tail, the dynamic
motion in a
| >> maneuver could cause the inertia of the fuselage to
overpower the
| >> aerodynamic stabilizing forces of the wing and tail. In
the worst cases
| >> the pilot lost control and the resulting abnormal air
loads caused
| >> airframe structural failure.
|
| > Sounds like a winner to me. Thank you for taking the
time and interest.
| > Dudley Henriques
|
| I'm not quite sure what that means, as far as what motion
the fuselage actually
| takes.
|
| Does the nose veer off of the line of flight, or does
something else happen?
| --
| Jim in NC
|

[Morgans[_2_]]

"Jim Macklin" > wrote

> Lomcevak Tumble - Aerobatic Maneuver Demonstrations -
> Fighter ... Student Air Show Pilot, Carl, gets cockpit
> instruction on flying the Lomcemvak tumbling maneuver.
> Fighter Combat International lists our Adventure Home ...
> www.fightercombat.com/vid_03Sep04.htm - 23k - Cached -
> Similar pages

So the motion of inertial coupling is similar to a lomcevak? That I understand.

Thanks.
--
Jim in NC