Autopilot questions for small GA aircraft

On May 8, 1:52 pm, chris wrote:
On May 8, 1:22 pm, Mxsmanic wrote:

Some questions on autopilots for pilots of small GA aircraft:

1. Do you have an autopilot in your aircraft? If so, how many axes/modes?

Some of the aircraft I fly do have them. All are single axis. You can
select HDG to follow the bug or NAV to follow a VOR, and some other
modes I haven't tried. One apparently will follow the GPS but I
couldn't figure the GPS out last time I flew that plane. One of the
other club planes, a Twin Comanche has alt hold as well as hdg hold. I
think a couple of our planes have autopilot disconnect switches handy
to your left hand as well.

The Clubs 172R will hold heading and altitude, and runs on NAV, HDG
or GPS modes. I liken its GPS to using the VI text editor in Linux -
only those who know how to use it can use it. The rest of us just use
the radio function and thats it.

2. Which modes do you find yourself using most often, and in what conditions?

HDG mode is all I have ever used, when I have trimmed it up and am on
track I sometimes set the autopilot up and sit back and relax.



3. Do you use your autopilot differently between VFR and IFR flight? If so,
what do you do differently?

N/A - don't fly IFR



4. How much do you trust your autopilot? Have you experienced failures? Were
they inconveniences or did they impact safety?

Seems to work OK, just have to remember that if you decide to change
direction the control column will strongly resist you trying to turn
it. Apparently a sharp yank will disconnect autopilot but have not
tried that. Gives you a fright when you go to turn left and it won't
turn!!

It was demonstrated to me in the clubs PA28 when I did my type rating
and you have to give it a fairly strong wrench to override it. And
yes, its quite scary. The 172 has an override switch on the controls.

5. Do you find that autopilots add safety or merely add convenience?

Using autopilot I am more likely to fly straight along the track
rather than wobbling around like I normally do

Convenience. I don't see it being safer than hand flying as you don't
really have ready control over the aircraft. One of our local
airlines entire Beech 1900D fleet was ordered without autopilot. When
the CEO was asked why he said, "we're paying for 2 pilots why pay for
a 3rd?"

6. Excluding situations in which autopilot is required (autolands, RVSM,
etc.), are there situations in which you prefer not to fly without an
autopilot?

I only use it for decent cross country flights, everything else,
including takeoff and landing I switch it off.

Some of the aircraft I fly do have them. All are single axis. You can
select HDG to follow the bug or NAV to follow a VOR, and some other
modes I haven't tried. One apparently will follow the GPS but I
couldn't figure the GPS out last time I flew that plane. One of the
other club planes, a Twin Comanche has alt hold as well as hdg hold. I
think a couple of our planes have autopilot disconnect switches handy
to your left hand as well.

The Clubs 172R will hold heading and altitude, and runs on NAV, HDG
or GPS modes. I liken its GPS to using the VI text editor in Linux -
only those who know how to use it can use it. The rest of us just use
the radio function and thats it.

Someone is going to have to show me how to use that some time!!

Mxsmanic wrote in
:



Other comments welcome as well, of course.


Like "you;'re a fjukkwit"?

Bertie

In a previous article, Mxsmanic said:
Some questions on autopilots for pilots of small GA aircraft:

1. Do you have an autopilot in your aircraft? If so, how many axes/modes?

Of our club's 4 aircraft, two have simple heading-only, and two have an
additional altitude hold. We recently sold the only one that didn't have
an autopilot at all.

2. Which modes do you find yourself using most often, and in what conditions?

When I use an autopilot, I only use HDG. I don't trust the NAV mode, and
I prefer to hand fly approaches. I use the HDG mode a lot when I'm
droning along on airways, but don't use the altitude hold so I have
something to do.


3. Do you use your autopilot differently between VFR and IFR flight? If so,
what do you do differently?

VFR, I hardly use it at all, except maybe when I'm checking a chart - the
rest of the time I want the option to throw it into a steep bank when the
mood strikes me or I want to look at something on the ground. IFR, I use
the heading mode most of the time en-route. Usually when I trim the plane
correctly I don't need the altitude hold, so I hardly use it.

4. How much do you trust your autopilot? Have you experienced failures? Were
they inconveniences or did they impact safety?

When I first started using the club planes that had autopilots (I trained
in the one that didn't have an autopilot), the first time I tried one it
put me into a 30 degree bank away from my course. If it hadn't been good
VMC, it might have been a safety impact. But only an idiot would try an
autopilot for the first time in IMC.

5. Do you find that autopilots add safety or merely add convenience?

Both. Last week when I was doing my IPC I started to get airsick. I
immediately turned on the autopilot so I could take a break.

6. Excluding situations in which autopilot is required (autolands, RVSM,
etc.), are there situations in which you prefer not to fly without an
autopilot?

Already answered.


--
Paul Tomblin http://blog.xcski.com/
Whenever someone says something exceedingly stupid, I feel it my duty to
educate them. Plus, everyone else leaves and the meeting becomes de
facto over. -- Rob Russell understands meetings

Paul Tomblin writes:

Usually when I trim the plane
correctly I don't need the altitude hold, so I hardly use it.

What about using the autopilot to trim, and then turning it off? I do this in
simulation, but only because the sim doesn't allow extremely precise trim
adjustments (as far as I know).

But only an idiot would try an autopilot for the first time in IMC.

I dunno. A pilot who isn't IR might try to turn on the autopilot upon finding
himself in IMC in order to keep the aircraft straight and narrow while he
gathers his wits about him, even though he might not have ever had occasion to
use it previously. It would be a reasonably logical thing to try.

Both. Last week when I was doing my IPC I started to get airsick. I
immediately turned on the autopilot so I could take a break.

What is IPC?

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

In a previous article, Mxsmanic said:
Paul Tomblin writes:
Usually when I trim the plane
correctly I don't need the altitude hold, so I hardly use it.

What about using the autopilot to trim, and then turning it off? I do this in
simulation, but only because the sim doesn't allow extremely precise trim
adjustments (as far as I know).

Recent aircraft (like the Cirrus) have a switch that automatically trims
off all the control force that you or your autopilot are holding. But the
sort of aircraft I can afford don't have that - you have to be pretty
close to trimmed before you can use the altitude hold.

But only an idiot would try an autopilot for the first time in IMC.

I dunno. A pilot who isn't IR might try to turn on the autopilot upon finding
himself in IMC in order to keep the aircraft straight and narrow while he
gathers his wits about him, even though he might not have ever had occasion to
use it previously. It would be a reasonably logical thing to try.

Sure, but it would be more logical to try out the autopilot when you're
checking out in the aircraft in the first place.

Both. Last week when I was doing my IPC I started to get airsick. I
immediately turned on the autopilot so I could take a break.

What is IPC?

Instrument Proficiency Check.


--
Paul Tomblin http://blog.xcski.com/
C has features?? I thought the whole point of that language was to
offer nothing but bare metal.
-- David P. Murphy

Paul Tomblin writes:

Recent aircraft (like the Cirrus) have a switch that automatically trims
off all the control force that you or your autopilot are holding.

Sounds like aircraft will eventually go the way of cars, with only a few
idiot-light indicators and perhaps an airspeed indicator.

I can see trimming off force for the pilot, but I'm puzzled by the autopilot
interaction. Don't most autopilots work by adjusting trim to begin with (at
least for altitude)?

But the
sort of aircraft I can afford don't have that - you have to be pretty
close to trimmed before you can use the altitude hold.

What happens if you are far away when you engage the autopilot?

Sure, but it would be more logical to try out the autopilot when you're
checking out in the aircraft in the first place.

True, but when you're stuck in fog and you don't know anything about flying on
instruments, it might be instinctive to reach for something that could fly the
plane for you and give you some time to think of a way out of your situation.

Instrument Proficiency Check.

Were you engaged in unusual maneuvers that made you sick? I don't know what
an IPC involves. One of my concerns about ever flying in a small airplane is
that the movements might make me sick, although I've never been airsick in
large aircraft (apart from some queasiness on one or two flights when I was
already sick with something else and we were flying through turbulence).

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

In a previous article, Mxsmanic said:
Paul Tomblin writes:
Recent aircraft (like the Cirrus) have a switch that automatically trims
off all the control force that you or your autopilot are holding.

Sounds like aircraft will eventually go the way of cars, with only a few
idiot-light indicators and perhaps an airspeed indicator.

Sounds like you know very little about what it means to pilot an aircraft.

But the
sort of aircraft I can afford don't have that - you have to be pretty
close to trimmed before you can use the altitude hold.

What happens if you are far away when you engage the autopilot?

It disengages. If you're close but not right on, it flashes a "trim up"
or "trim down" light at you.

Sure, but it would be more logical to try out the autopilot when you're
checking out in the aircraft in the first place.

True, but when you're stuck in fog and you don't know anything about flying on
instruments, it might be instinctive to reach for something that could fly the
plane for you and give you some time to think of a way out of your situation.

Part of checking out in a new aircraft is becoming familiar with *all*
aircraft systems - and you should do that in perfect weather. If you
haven't become familiar with all aircraft systems then you shouldn't be
flying it alone in marginal weather.

Instrument Proficiency Check.

Were you engaged in unusual maneuvers that made you sick? I don't know what

Yes. One of the required skills for instrument flight is recovery from
unusual attitudes. You close your eyes, your instructor tries to get you
disoriented, puts the plane in an unusual attitude - usually either a
steep spiral dive or a steep climb near stall. It's the "get you
disoriented" part that got me sick - my instructor likes to give you a
real roller coaster. The first recovery, I counted four really hard
positive G pulls, a couple of hard negative G pushes,some hard slips and
skids, and the stall horn went off a couple of times. The second recovery
was about the same.

--
Paul Tomblin http://blog.xcski.com/
Surely the 98% of DNA we share with monkeys must be enough to stop
people from sinking this low.
-- Frossie

Mxsmanic wrote in
:

Paul Tomblin writes:

Recent aircraft (like the Cirrus) have a switch that automatically
trims off all the control force that you or your autopilot are
holding.

Sounds like aircraft will eventually go the way of cars, with only a
few idiot-light indicators and perhaps an airspeed indicator.

then maybe you'll be able to fly!
nah.

Bertie

Mxsmanic wrote in
:

Paul Tomblin writes:

Usually when I trim the plane
correctly I don't need the altitude hold, so I hardly use it.

What about using the autopilot to trim, and then turning it off? I do
this in simulation, but only because the sim doesn't allow extremely
precise trim adjustments (as far as I know).

You do thast because you're a fjukkwit.


Bertie