Autopilot fighting for control

[Mxsmanic]

In simulation, if I set the autopilot to maintain the altitude, and
then try to change pitch with the controls, the control surfaces
barely move, and I can hardly have any effect on pitch.

I think this is a limitation of the simulator. My guess is that, in
real life, the autopilot continuously adjusts trim, and so, if you try
to change pitch with the yoke, the A/P retrims to cancel out your
efforts, and the net effect is that you can change pitch, but you must
exert very high control pressures to do it (in order to overcome the
trim that the A/P is applying to neutralize your efforts).

Is this correct? I can see why this is difficult to simulate with
controls that don't provide feedback, but I want to make sure that I
understand the difference between the sim's way of doing it and the
real thing.

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[Robert M. Gary]

Mxsmanic wrote:
> In simulation, if I set the autopilot to maintain the altitude, and
> then try to change pitch with the controls, the control surfaces
> barely move, and I can hardly have any effect on pitch.
>
> I think this is a limitation of the simulator. My guess is that, in
> real life, the autopilot continuously adjusts trim, and so, if you try
> to change pitch with the yoke, the A/P retrims to cancel out your
> efforts, and the net effect is that you can change pitch, but you must
> exert very high control pressures to do it (in order to overcome the
> trim that the A/P is applying to neutralize your efforts).
>
> Is this correct? I can see why this is difficult to simulate with
> controls that don't provide feedback, but I want to make sure that I
> understand the difference between the sim's way of doing it and the
> real thing.

It takes pretty minimual control to over power the autopilot. However,
if you disrupt it a great deal (make a big pitch change for instance)
the autopilot may overcorrect a few times before settling back to the
correct pitch. The ability to return to the correct pitch with minimal
over correcting is a function of the quality of the autopilot.
Sometimes when you make changes such as lowering flaps you need to
"help" the autopilot but holding the yoke in the right place for a bit
until the autopilot figures out what is going on. This even with the
more expensive autopilots (like the new KAP140).

However, it is very easy to hand fly the plane while the autopilot is
on. The Cessna training instructors told us that they routinely hand
fly procedure holds on approach w/o changing the mode on the autopilot,
just over powering it.
In my plane I'll hand fly through turb but I'll leave the autopilot on
because it gives me a nudge back to course (i.e. I can feel it trying
to pull me back on course). If I take my hands off during turb though
it will make the turb worse.


-Robert

[Ron Natalie]

Mxsmanic wrote:
> In simulation, if I set the autopilot to maintain the altitude, and
> then try to change pitch with the controls, the control surfaces
> barely move, and I can hardly have any effect on pitch.
>

There's a big difference between airline control movement and it's
relationship to trim than light aircraft. I'll restrict our talk
to light aircraft.

> I think this is a limitation of the simulator. My guess is that, in
> real life, the autopilot continuously adjusts trim, and so, if you try
> to change pitch with the yoke, the A/P retrims to cancel out your
> efforts, and the net effect is that you can change pitch, but you must
> exert very high control pressures to do it (in order to overcome the
> trim that the A/P is applying to neutralize your efforts).

My autopilot has both pitch servos and trim. You push on the yoke
it has the same impact that it would if the autopilot wasn't there.
However, what the autopilot does endeavor to do is adjust the trim
so that it's always "trimmed" which means it may try to trim away
your force (if you are pitching it away from where it thinks it
should be). The autopilot does this so that if you kick off the
autopilot it's giving you a plane that is in trim.

[Ron Natalie]

Robert M. Gary wrote:

> Sometimes when you make changes such as lowering flaps you need to
> "help" the autopilot but holding the yoke in the right place for a bit
> until the autopilot figures out what is going on. This even with the
> more expensive autopilots (like the new KAP140).

I don't have to do this with the 55X provided that I make a power
adjustment to go with the new configuration.
>
> However, it is very easy to hand fly the plane while the autopilot is
> on. The Cessna training instructors told us that they routinely hand
> fly procedure holds on approach w/o changing the mode on the autopilot,
> just over powering it.

Ick. What's the point? Which mode where they in to start with?

[[email protected]]

Robert M. Gary wrote:

>
> However, it is very easy to hand fly the plane while the autopilot is
> on.
> -Robert

Ouch.

My old Skylane has a KAP-150.

"Easily" over power the yoke/trim with the AP on? No.

I have a nice big red circuit breaker handle on the trim breaker just
for this reason.

Pre-start includes saying out-loud: "Run-away trim, pull red breaker."

Fly an approach while overpowering the AP?

Who are these Cessna instructors?

They might want to RTFM, that's what CWS is for.

Adam K.

[Robert M. Gary]

Ron Natalie wrote:
> Robert M. Gary wrote:
> > However, it is very easy to hand fly the plane while the autopilot is
> > on. The Cessna training instructors told us that they routinely hand
> > fly procedure holds on approach w/o changing the mode on the autopilot,
> > just over powering it.
>
> Ick. What's the point? Which mode where they in to start with?

The autopilot is in nav/approach mode. This is coupled with a G1000 so
it doesn't do holds on its own (its based on the 430 software, not the
480 software). So, rather than switch the autopilot into heading mode,
and then back into approach capture mode, they leave it in approach
mode. That way, as soon as you turn in bound you can just let go and it
flys the approach (KAP140 has pitch control and can fly a GS). It just
saves you from leaving nav mode and havnig to go back into capture
mode. I think part of their point is that it doesn't do any harm to out
mussle the autopilot.

-Robert

[Robert M. Gary]

Ron Natalie wrote:
> My autopilot has both pitch servos and trim. You push on the yoke
> it has the same impact that it would if the autopilot wasn't there.
> However, what the autopilot does endeavor to do is adjust the trim
> so that it's always "trimmed" which means it may try to trim away
> your force (if you are pitching it away from where it thinks it
> should be). The autopilot does this so that if you kick off the
> autopilot it's giving you a plane that is in trim.

Some autopilots don't have trim servos and have "up" and "down"lights
on the autopilot display asking the pilot to retrim. The autopilot
normally flys a bit out of trim but anything outside the params results
in a request of the pilot to trim. The purpose is just as you
mentioned. You would be sad to find yourself in a nose down dive after
disconnecting the autopilot.
The autopilots that have "pitch control" (terminology used to denote
that it does more than hold altitude, it holds VS) usually have trim
control as well. The familiar "Trim, in motion" annunciator that seems
to go off everytime I click the mic to call tower in the G1000
aircraft. ;)

-Robert

[A Lieberma]

Mxsmanic > wrote in
:

> but I want to make sure that I
> understand the difference between the sim's way of doing it and the
> real thing.

Why do you need to understand?

What's the difference if you are never going to sit in a REAL PLANE.

Allen

[Mxsmanic]

Ron Natalie writes:

> There's a big difference between airline control movement and it's
> relationship to trim than light aircraft. I'll restrict our talk
> to light aircraft.

The 737-800 sim has a very fancy autopilot (like the real thing), and
when you touch the controls, it switches to CWS pitch or roll mode.
Unfortunately, I don't understand how that works yet (especially when
it comes to getting the A/P to take over again), so I don't use it
much.

The A/P in the Baron seems straightforward enough. I note that if I
set it to hold altitude only, it resists any change in heading as
well; not sure if that is the sim or an accurate representation of
real life (the A/P is marked KFC225, whatever that is).

> My autopilot has both pitch servos and trim. You push on the yoke
> it has the same impact that it would if the autopilot wasn't there.
> However, what the autopilot does endeavor to do is adjust the trim
> so that it's always "trimmed" which means it may try to trim away
> your force (if you are pitching it away from where it thinks it
> should be). The autopilot does this so that if you kick off the
> autopilot it's giving you a plane that is in trim.

Do you feel more pressure in the controls as the A/P tries to trim
away your pitch change?

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[Mxsmanic]

Robert M. Gary writes:

> The autopilots that have "pitch control" (terminology used to denote
> that it does more than hold altitude, it holds VS) usually have trim
> control as well. The familiar "Trim, in motion" annunciator that seems
> to go off everytime I click the mic to call tower in the G1000
> aircraft. ;)

Doesn't trim make its own noise? I've read notes in voice recorder
transcripts that mention "trim wheel moving at autopilot speed,"
although that is in large aircraft. I assume it must make quite a
noise if this gets recorded.

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[Robert M. Gary]

Mxsmanic wrote:
> Robert M. Gary writes:
>
> > The autopilots that have "pitch control" (terminology used to denote
> > that it does more than hold altitude, it holds VS) usually have trim
> > control as well. The familiar "Trim, in motion" annunciator that seems
> > to go off everytime I click the mic to call tower in the G1000
> > aircraft. ;)
>
> Doesn't trim make its own noise? I've read notes in voice recorder
> transcripts that mention "trim wheel moving at autopilot speed,"
> although that is in large aircraft. I assume it must make quite a
> noise if this gets recorded.

Its an annunciator just like any other. There is one annunciator that
has multiple preprogrammed channels. I believe mine has 40 different
things it can say, although few are hooked up. A signal goes down the
wire to the annunciator and the voice speaks. Its not part of the
autopilot or trim system itself.
Mine often says "Check landing gear" just as I call up tower when on
approach. Its a bit annoying.

-Robert

[Robert M. Gary]

Mxsmanic wrote:
> Do you feel more pressure in the controls as the A/P tries to trim
> away your pitch change?

God yes. It only says "trim in motion" for extream changes. This is
usually when moving flaps or if you pull back power but forget to
reduce the VS. I've gotten it into situations where it gets on the back
side of the pitch control (more pitch up results in less VS) and it
starts to fight, I push down, it moves the trim forward and the
pressure becomes MUCH higher. The best solution at that point is to
disengage the altitude of course the real solution is to reduce the VS
before reducing power and not let the AP get behind the pitch curve.

-Robert

[Mxsmanic]

Robert M. Gary writes:

> Mine often says "Check landing gear" just as I call up tower when on
> approach. Its a bit annoying.

The simulated Baron I have says "Check gear!" constantly below certain
throttle settings (I'm not exactly sure what sets it off, though).
It's very irritating, but if it's in the sim, it must be doing that in
real life as well.

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[Jim Macklin]

If the autopilot is over=powered the auto-trim will run to
try to get control forces back in the acceptable range.
This will place the airplane seriously out of trim. A pilot
can over-power the autopilot, but if this is done it should
be either as a demonstration during checkout or in response
to an autopilot actuator run-away. The pilot should
maintain attitude control, over-powering the autopilot while
they
1 push the disconnect button
2 pull the circuit breaker
3 manually retrim
4 land ASAP



--
James H. Macklin
ATP,CFI,A&P

"Robert M. Gary" > wrote in message
oups.com...
|
| Mxsmanic wrote:
| > In simulation, if I set the autopilot to maintain the
altitude, and
| > then try to change pitch with the controls, the control
surfaces
| > barely move, and I can hardly have any effect on pitch.
| >
| > I think this is a limitation of the simulator. My guess
is that, in
| > real life, the autopilot continuously adjusts trim, and
so, if you try
| > to change pitch with the yoke, the A/P retrims to cancel
out your
| > efforts, and the net effect is that you can change
pitch, but you must
| > exert very high control pressures to do it (in order to
overcome the
| > trim that the A/P is applying to neutralize your
efforts).
| >
| > Is this correct? I can see why this is difficult to
simulate with
| > controls that don't provide feedback, but I want to make
sure that I
| > understand the difference between the sim's way of doing
it and the
| > real thing.
|
| It takes pretty minimual control to over power the
autopilot. However,
| if you disrupt it a great deal (make a big pitch change
for instance)
| the autopilot may overcorrect a few times before settling
back to the
| correct pitch. The ability to return to the correct pitch
with minimal
| over correcting is a function of the quality of the
autopilot.
| Sometimes when you make changes such as lowering flaps you
need to
| "help" the autopilot but holding the yoke in the right
place for a bit
| until the autopilot figures out what is going on. This
even with the
| more expensive autopilots (like the new KAP140).
|
| However, it is very easy to hand fly the plane while the
autopilot is
| on. The Cessna training instructors told us that they
routinely hand
| fly procedure holds on approach w/o changing the mode on
the autopilot,
| just over powering it.
| In my plane I'll hand fly through turb but I'll leave the
autopilot on
| because it gives me a nudge back to course (i.e. I can
feel it trying
| to pull me back on course). If I take my hands off during
turb though
| it will make the turb worse.
|
|
| -Robert
|

[Jim Macklin]

If the autopilot is flying, use the autopilot console to fly
the airplane. Over-powering the autopilot is always BAD
technique. Many autopilots will disconnect if they sense a
problem which can include input on the control wheel.

Autopilots have a supplement in the POH, it should be read
and understood.



"Robert M. Gary" > wrote in message
ups.com...
|
| Ron Natalie wrote:
| > Robert M. Gary wrote:
| > > However, it is very easy to hand fly the plane while
the autopilot is
| > > on. The Cessna training instructors told us that they
routinely hand
| > > fly procedure holds on approach w/o changing the mode
on the autopilot,
| > > just over powering it.
| >
| > Ick. What's the point? Which mode where they in to
start with?
|
| The autopilot is in nav/approach mode. This is coupled
with a G1000 so
| it doesn't do holds on its own (its based on the 430
software, not the
| 480 software). So, rather than switch the autopilot into
heading mode,
| and then back into approach capture mode, they leave it in
approach
| mode. That way, as soon as you turn in bound you can just
let go and it
| flys the approach (KAP140 has pitch control and can fly a
GS). It just
| saves you from leaving nav mode and havnig to go back into
capture
| mode. I think part of their point is that it doesn't do
any harm to out
| mussle the autopilot.
|
| -Robert
|

[Jim Macklin]

The Cessna instructors are probably showing that the servos
can be over-powered with pilot muscle, no reason to lose
control. But I'm sure they also teach the location of CWS,
the trim switch, the red disconnect button and the A/P CB
and avionics master.


> wrote in message
ups.com...
|
| Robert M. Gary wrote:
|
| >
| > However, it is very easy to hand fly the plane while the
autopilot is
| > on.
| > -Robert
|
| Ouch.
|
| My old Skylane has a KAP-150.
|
| "Easily" over power the yoke/trim with the AP on? No.
|
| I have a nice big red circuit breaker handle on the trim
breaker just
| for this reason.
|
| Pre-start includes saying out-loud: "Run-away trim, pull
red breaker."
|
| Fly an approach while overpowering the AP?
|
| Who are these Cessna instructors?
|
| They might want to RTFM, that's what CWS is for.
|
| Adam K.
|

[Robert M. Gary]

Jim Macklin wrote:
> If the autopilot is flying, use the autopilot console to fly
> the airplane. Over-powering the autopilot is always BAD
> technique. Many autopilots will disconnect if they sense a
> problem which can include input on the control wheel.

I'm simply quoted chapter and verse what the Cessna factory instructors
are saying. If you have a disagreement with the technique you are free
to discuss it with them.

[Robert M. Gary]

Mxsmanic wrote:
> Robert M. Gary writes:
>
> > Mine often says "Check landing gear" just as I call up tower when on
> > approach. Its a bit annoying.
>
> The simulated Baron I have says "Check gear!" constantly below certain
> throttle settings (I'm not exactly sure what sets it off, though).
> It's very irritating, but if it's in the sim, it must be doing that in
> real life as well.

Its the poor man's gear check. On my plane its anything below 12" MP.
However, most of the time I can't run more than 10" MP when being
vectored on the approach to a lower altitude without gaining speed, so
I have to listen to it. However, I have a 2 phase cancel button. If I
press it once, it overrides the "check gear" annunciator for something
like 30 seconds. If I press it twice quickly it overrides it for 5
minutes.

-Robert

[Jim Macklin]

I will at the next pilot meeting that Cessna hosts in their
meeting room just south of the Wallace plant on K42. These
are regular CFI meetings jointly with the FAA and Cessna and
other groups.

BTW, the factory instructors can be wrong. Or the person
who reported to you could be wrong. Part of a good
autopilot checkout should include showing that the servos
are not so strong that a pilot can't maintain control. But
that is a demo, the correct procedure is the hand fly, with
or without the FD or use the A/P console to command the
airplane.

Of course if the object is to have a student get an airplane
with the trim 100% wrong...


--
James H. Macklin
ATP,CFI,A&P

"Robert M. Gary" > wrote in message
ups.com...
|
| Jim Macklin wrote:
| > If the autopilot is flying, use the autopilot console to
fly
| > the airplane. Over-powering the autopilot is always BAD
| > technique. Many autopilots will disconnect if they
sense a
| > problem which can include input on the control wheel.
|
| I'm simply quoted chapter and verse what the Cessna
factory instructors
| are saying. If you have a disagreement with the technique
you are free
| to discuss it with them.
|

[Ron Natalie]

Robert M. Gary wrote:
> Ron Natalie wrote:
>> Robert M. Gary wrote:
>>> However, it is very easy to hand fly the plane while the autopilot is
>>> on. The Cessna training instructors told us that they routinely hand
>>> fly procedure holds on approach w/o changing the mode on the autopilot,
>>> just over powering it.
>> Ick. What's the point? Which mode where they in to start with?
>
> The autopilot is in nav/approach mode. This is coupled with a G1000 so
> it doesn't do holds on its own (its based on the 430 software, not the
> 480 software). So, rather than switch the autopilot into heading mode,
> and then back into approach capture mode, they leave it in approach
> mode. That way, as soon as you turn in bound you can just let go and it
> flys the approach (KAP140 has pitch control and can fly a GS). It just
> saves you from leaving nav mode and havnig to go back into capture
> mode. I think part of their point is that it doesn't do any harm to out
> mussle the autopilot.
>
Still Ick. I don't know about the KAP150, but switching autopilot
modes is just a button push (well, two, but you can mash NAV and
APR at the same time, I even can do HDG+NAV+APR together without
strain). Switching the autopilot modes is a lot easier than
fighting the thing trying to drive you back to the final course.

[Ron Natalie]

Jim Macklin wrote:
> If the autopilot is flying, use the autopilot console to fly
> the airplane. Over-powering the autopilot is always BAD
> technique. Many autopilots will disconnect if they sense a
> problem which can include input on the control wheel.
>
Yep, caused an airliner to crash in Russia a few years back
(among other issues).

[Robert M. Gary]

Ron Natalie wrote:
> Still Ick. I don't know about the KAP150, but switching autopilot
> modes is just a button push (well, two, but you can mash NAV and
> APR at the same time, I even can do HDG+NAV+APR together without
> strain). Switching the autopilot modes is a lot easier than
> fighting the thing trying to drive you back to the final course.

It just have to recapture.

[Robert M. Gary]

Jim Macklin wrote:
> Of course if the object is to have a student get an airplane
> with the trim 100% wrong...

How does hand flying a procedure turn effect the trim? I've not noticed
this myself. You think the role servos get confused and try to change
the pitch? I'm not following.
-Robert

[Ron Natalie]

Robert M. Gary wrote:
> Ron Natalie wrote:
>> Still Ick. I don't know about the KAP150, but switching autopilot
>> modes is just a button push (well, two, but you can mash NAV and
>> APR at the same time, I even can do HDG+NAV+APR together without
>> strain). Switching the autopilot modes is a lot easier than
>> fighting the thing trying to drive you back to the final course.
>
> It just have to recapture.
>
eh?

[Barney Rubble]

The KFC225 relates to Kentucky Fried Chicken. They started out in the
chicken meal business and branched out into aircraft autopilots. Bit like
Nokia, who started in bicycle tires and got into cell phones.

"Mxsmanic" > wrote in message
...

> real life (the A/P is marked KFC225, whatever that is).

[Jim Macklin]

King Flight Control


King Radios, Olathe, KS


"Barney Rubble" > wrote in message
...
| The KFC225 relates to Kentucky Fried Chicken. They started
out in the
| chicken meal business and branched out into aircraft
autopilots. Bit like
| Nokia, who started in bicycle tires and got into cell
phones.
|
| "Mxsmanic" > wrote in message
| ...
|
| > real life (the A/P is marked KFC225, whatever that is).
|
|

[Mxsmanic]

"Jim Macklin" > writes:

> King Flight Control
>
>
> King Radios, Olathe, KS

Apparently part of Honeywell now.

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[Robert M. Gary]

Ron Natalie wrote:
> Jim Macklin wrote:
> > If the autopilot is flying, use the autopilot console to fly
> > the airplane. Over-powering the autopilot is always BAD
> > technique. Many autopilots will disconnect if they sense a
> > problem which can include input on the control wheel.
> >
> Yep, caused an airliner to crash in Russia a few years back
> (among other issues).

Ok, if you're going to bring up an incident tell the entire story. The
captains 15 year old son was at the controls at the time.

-Robert

[Mxsmanic]

Robert M. Gary writes:

> Ok, if you're going to bring up an incident tell the entire story. The
> captains 15 year old son was at the controls at the time.

Michael Crichton's novel comes true! (Almost.)

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[Ron Natalie]

Robert M. Gary wrote:
> Ron Natalie wrote:
>> Jim Macklin wrote:
>>> If the autopilot is flying, use the autopilot console to fly
>>> the airplane. Over-powering the autopilot is always BAD
>>> technique. Many autopilots will disconnect if they sense a
>>> problem which can include input on the control wheel.
>>>
>> Yep, caused an airliner to crash in Russia a few years back
>> (among other issues).
>
> Ok, if you're going to bring up an incident tell the entire story. The
> captains 15 year old son was at the controls at the time.
>
Yes, that was the cause of the AP disconnect. The 15 yo overpowered
the autopilot causing it to silently disconnect the aileron servos.
Neither the right seat pilot nor the captain standing behind noticed
this. When the airplane started roll subsequently they assumed they
had somehow commanded an autopilot-controlled hold entry. They
then allowed the bank to progress to 50 degrees.

This leads to an incipient problem you can have in a private aircraft
as well. Without sufficient power, the autopilot trying to maintain
altitude can drive the aircraft into a stall. It was finally at the
onset of the prestall buffeting that the copilot started to try to
recover, unfortunately while you can overpower an autopilot easily,
overpowering a 15yo holding the other yoke is not as easy.

[Ron Natalie]

Mxsmanic wrote:
> Robert M. Gary writes:
>
>> Ok, if you're going to bring up an incident tell the entire story. The
>> captains 15 year old son was at the controls at the time.
>
> Michael Crichton's novel comes true! (Almost.)
>

Crichton's novel post dates (and was almost certainly influenced by)
the incident.

[Robert M. Gary]

Ron Natalie wrote:
> Yes, that was the cause of the AP disconnect. The 15 yo overpowered
> the autopilot causing it to silently disconnect the aileron servos.
> Neither the right seat pilot nor the captain standing behind noticed
> this. When the airplane started roll subsequently they assumed they
> had somehow commanded an autopilot-controlled hold entry. They
> then allowed the bank to progress to 50 degrees.
>
> This leads to an incipient problem you can have in a private aircraft
> as well. Without sufficient power, the autopilot trying to maintain
> altitude can drive the aircraft into a stall. It was finally at the
> onset of the prestall buffeting that the copilot started to try to
> recover, unfortunately while you can overpower an autopilot easily,
> overpowering a 15yo holding the other yoke is not as easy.

Its hard to compare an transport aircraft quality autopilot with an air
mixer. The specific problems brought up in the Russian accident were 1)
The pilots were never trained that overpowering the autopilot would
result in a *partial* disconnect. The roll disconnected but not the
pitch and 2) When such an event happens the autopilot disengage horn
does not sound. Clearly a misstep in design.

Now compare that to the Cessna. If you tell the Cessna to hold altitude
and pull power all the way back to idle it will get pretty slow, but it
will not stall, the nose will drop and the computer is smart enough to
give up altitude to prevent stall (I've done it). There is no partial
disconnect in the Cessna. The autopilot is either engaged or not. If
you press the red button the entire thing goes off line. In the above
accident a non-rated person was banking the aircraft in excess of 60
degrees of roll when the problem happened. If you use more than 60
degrees of roll in your procedure turn, you probably have bigger
problems in your Cessna than the autopilot.

-Robert

[Mxsmanic]

Ron Natalie writes:

> This leads to an incipient problem you can have in a private aircraft
> as well. Without sufficient power, the autopilot trying to maintain
> altitude can drive the aircraft into a stall. It was finally at the
> onset of the prestall buffeting that the copilot started to try to
> recover, unfortunately while you can overpower an autopilot easily,
> overpowering a 15yo holding the other yoke is not as easy.

The 15yo was trying to steer the aircraft the wrong way?

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[Ron Natalie]

Mxsmanic wrote:
> Ron Natalie writes:
>
>> This leads to an incipient problem you can have in a private aircraft
>> as well. Without sufficient power, the autopilot trying to maintain
>> altitude can drive the aircraft into a stall. It was finally at the
>> onset of the prestall buffeting that the copilot started to try to
>> recover, unfortunately while you can overpower an autopilot easily,
>> overpowering a 15yo holding the other yoke is not as easy.
>
> The 15yo was trying to steer the aircraft the wrong way?
>
The report I read theorized that the instructions that pilot
was shouting was interpretted as to hold the wheel in a neutral
position while the copilot was trying to roll the plane back level.

[Peter Clark]

On Tue, 10 Oct 2006 21:35:47 -0500, "Jim Macklin"
> wrote:

>The Cessna instructors are probably showing that the servos
>can be over-powered with pilot muscle, no reason to lose
>control. But I'm sure they also teach the location of CWS,
>the trim switch, the red disconnect button and the A/P CB
>and avionics master.

There's no CWS on the KAP140 install in the NAV3 equipped Cessna line.
Probably on the Mustang when it comes out, but not the SEPs.

It's been a few years so things might be different now, but IIRC, the
class doesn't teach leaving things in NAV mode to fly procedure turns,
but teaches doing a partial-panel approach by selecting wing-level and
flying it that way. Personally with a working aircraft I always fly a
procedure turn w/ autopilot by changing it to HDG mode, flying the
procedure turn with the bug, and then re-arm APR on the inbound
intercept.

[Ron Natalie]

Peter Clark wrote:
..
>
> There's no CWS on the KAP140 install in the NAV3 equipped Cessna line.
> Probably on the Mustang when it comes out, but not the SEPs.

I've got CWS on my 55X. Frankly, I never use it.




> Personally with a working aircraft I always fly a
> procedure turn w/ autopilot by changing it to HDG mode, flying the
> procedure turn with the bug, and then re-arm APR on the inbound
> intercept.

That's what works for me. On the 55X, you can HDG+NAV+APR
at the same time and it holds the heading until the needle comes
alive (if you just NAV+APR, it may make a more agressive turn
towards the course).

[Peter Clark]

On Thu, 12 Oct 2006 15:35:28 -0400, Ron Natalie >
wrote:

>That's what works for me. On the 55X, you can HDG+NAV+APR
>at the same time and it holds the heading until the needle comes
>alive (if you just NAV+APR, it may make a more agressive turn
>towards the course).

Yea, same on the KAP140. I use HDG+APR and try for a 30-40deg
intercept angle. Seems to work.