AUTOPILOT PROS & CONS

All the comments about monitoring for failures are worthy of
consideration. And staying current enough to cope with those
failures is essential. You need to be able to hand fly it.

That said, one of the common features of instrument training is
that stick wiggling is featured and evaluated.

The success factor in serious IFR travelling is being the captain--
the flight manager. Making the in-flight decisions. Key example:
Coping with weather.

Can be that stick wiggling interferes with concentrating on the.
flight management duties. A good autopilot is a key tool at times
like that.

Folks pooh-pooh coupled approaches. Those who have actually
flown them, especially under low-light, minimum conditions know that
good
runway alignment when breaking out is essential. I'm not as good
as the autopilot, so I let it handle those situations.

FWIW. Bill Hale
Chicken.

Greg,

OK - it may be off color a bit, or it may already have been published
here (my apologies in either case) but have a look at this one :


Just saw it the other day in a movie theater. nice ad for a language
school.

--
Thomas Borchert (EDDH)

"Al" wrote in
:

Some autopilot failures are very subtle. I was shooting a coupled ILS
to minimums with a King autopilot in a Mooney. After capturing the
glideslope, I noticed the rate was about 75'/min more than I was used
to. As we got closer to DH, the DME was still showing about 2 miles to
the airport. I leveled at DH, and while motoring along 200' above the
houses, I tapped the Vor/loc. The GS needle snapped to the top of the
case. It was "stuck" centered, and the autopilot
was literally flying the needle. Iron Mike, indeed.

Technically speaking, that wasn't an autopilot failure, it was a GS needle
failure. The results would have been nearly identical if you were hand-
flying. Although you might have noticed inconcistencies in airplane
response more quickly and fixed it earlier. Then again, you might have been
so busy keeping the needle centered that it would have gone unnoticed until
you flew your plane right through someone's living room.

Hard to say.

The KAP 140 flys a better ILS than I can. It would be easy to forget
how to fly an ILS if you never hand flew one.

-Robert

I never use it. I don't feel like I'm flying if I don't have my hand on the yoke.

We have guys like that in CAP (most are 30 years older than me). The
problem is that those pilots cannot transition to the new G1000
aircraft because there is just no way to hand fly the plane, look for
traffic and exercise all the complex stuff the G1000 glass cockpit
provides. You really have to step back and manage the aircraft rather
than fly it. You need to know what the plane is doing and what it will
do next. The guys who are hand flying it are just keeping up and not
able to determine what the plane should do next. Of course the plane
can be flown just fine w/o the autopilot but passing the check ride
requires you to demonstrate using the G1000 features while airborne.

-Robert, CFI (G1000 instructor)

"Judah" wrote in message
. ..
"Al" wrote in
:

Some autopilot failures are very subtle. I was shooting a coupled ILS
to minimums with a King autopilot in a Mooney. After capturing the
glideslope, I noticed the rate was about 75'/min more than I was used
to. As we got closer to DH, the DME was still showing about 2 miles to
the airport. I leveled at DH, and while motoring along 200' above the
houses, I tapped the Vor/loc. The GS needle snapped to the top of the
case. It was "stuck" centered, and the autopilot
was literally flying the needle. Iron Mike, indeed.

Technically speaking, that wasn't an autopilot failure, it was a GS needle
failure.

Correct.

The results would have been nearly identical if you were hand-
flying. Although you might have noticed inconcistencies in airplane
response more quickly and fixed it earlier.

Naw, If I'd set the plane up for the descent, and got it exactly right the
first time, with no additional trim, I'd be real suspicious...Never happened
before.

Then again, you might have been
so busy keeping the needle centered that it would have gone unnoticed
until
you flew your plane right through someone's living room.

Hard to say.

It's really a matter of cross checking and a cynical attitude.

Al

On the Century-2000 equipped Bonanzas I fly, there's an interesting
trim problem with the AP, which is basicly that it doesn't trim.

Engage the AP while you're being vectored for the ILS and let it
fly the approach, as you keep reducing power to slow down and then
track the GS. As you slow down, you should be dialing in nose-up trim
(and, indeed, the AP prompts you to do this, but if you're not paying
attention, you can miss the flashing light).

Now, at DH, click off the AP to hand-fly the landing. All of a
sudden, you've got a fistfull of yoke trying to pull your arms out of
their sockets until you get the trim fixed. Even worse if you didn't
see the runway and clicked off the AP to execute the missed.

Of course, the AP is performing as designed, and it's the pilot who's
unairworthy, but it's a common enough mistake that I've got to believe
it's a design flaw in the system. If nothing else, it should have a
more obvious alert than a small blinking light outside of your main
visual scan. Like maybe a mechanical arm that smacks you upside your
head with a rolled-up sectional while a synthesized voice says, "Trim
up, trim up".

The auto-pilot should be running the trim, the annunciation
is intended to be advisory. Using the electric trim will
disengage the auto-pilot. I'm guessing that you have a bad
relay.
It is not airworthy as it is, you might be able to placard
it in-op until you can get it in the shop. Read the POH FM
supplement for a description of the required pre-flight
tests, you may not be doing them properly and thus the A/P
won't engage.

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



"Roy Smith" wrote in message
...
| On the Century-2000 equipped Bonanzas I fly, there's an
interesting
| trim problem with the AP, which is basicly that it doesn't
trim.
|
| Engage the AP while you're being vectored for the ILS and
let it
| fly the approach, as you keep reducing power to slow down
and then
| track the GS. As you slow down, you should be dialing in
nose-up trim
| (and, indeed, the AP prompts you to do this, but if you're
not paying
| attention, you can miss the flashing light).
|
| Now, at DH, click off the AP to hand-fly the landing. All
of a
| sudden, you've got a fistfull of yoke trying to pull your
arms out of
| their sockets until you get the trim fixed. Even worse if
you didn't
| see the runway and clicked off the AP to execute the
missed.
|
| Of course, the AP is performing as designed, and it's the
pilot who's
| unairworthy, but it's a common enough mistake that I've
got to believe
| it's a design flaw in the system. If nothing else, it
should have a
| more obvious alert than a small blinking light outside of
your main
| visual scan. Like maybe a mechanical arm that smacks you
upside your
| head with a rolled-up sectional while a synthesized voice
says, "Trim
| up, trim up".

Robert M. Gary wrote:
I never use it. I don't feel like I'm flying if I don't have my hand on the yoke.


We have guys like that in CAP (most are 30 years older than me). The
problem is that those pilots cannot transition to the new G1000
aircraft because there is just no way to hand fly the plane, look for
traffic and exercise all the complex stuff the G1000 glass cockpit
provides. You really have to step back and manage the aircraft rather
than fly it. You need to know what the plane is doing and what it will
do next. The guys who are hand flying it are just keeping up and not
able to determine what the plane should do next. Of course the plane
can be flown just fine w/o the autopilot but passing the check ride
requires you to demonstrate using the G1000 features while airborne.

-Robert, CFI (G1000 instructor)


I agree with everything you say, yet I wonder whether a single pilot can
effectively manage it all with an autopilot and also keep a good lookout
for traffic.

In article 5u4ag.20816$ZW3.8687@dukeread04,
Jim Macklin wrote:
The auto-pilot should be running the trim, the annunciation
is intended to be advisory. Using the electric trim will
disengage the auto-pilot. I'm guessing that you have a bad
relay.

There is no electric trim. I believe it's an option, but our boxes
don't have it.