How much is autopilot on commercial flights today?

[Mxsmanic]

How much of an average commercial flight on a large airline and
aircraft today is done automatically, via autopilot, autoland, and so
on? Including takeoff and landing. I know that the bulk of a flight
is on autopilot, which makes sense since autopilots are good at flying
planes and that's lots of hours to sit holding a yoke, but what about
the fun parts, such as takeoff and landing? Systems exist to fully
automate both, but are such systems routinely installed and used
today? Do airlines have policies that require or prohibit the use of
such systems under normal conditions? I've heard that in cruise
flight, at least, airlines want their pilots to stay on autopilot as
much as possible, to save fuel.

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[Robert M. Gary]

Mxsmanic wrote:
> I've heard that in cruise
> flight, at least, airlines want their pilots to stay on autopilot as
> much as possible, to save fuel.

To stay awake.

[Brian[_1_]]

My friend that flys 737's for Alaska Airlines says that he hits that
autopilot button 50 feet off of the ground on Take off and takes the
controls back 50 feet over the ground on landing.

I can't vouch for how accurate it is, but it would surprise me to be
fairly accurate.

Brian

[Robert M. Gary]

Brian wrote:
> My friend that flys 737's for Alaska Airlines says that he hits that
> autopilot button 50 feet off of the ground on Take off and takes the
> controls back 50 feet over the ground on landing.

If he's maintaining CAT III currency he's getting at least some auto
lands as well.

-Robert

[B A R R Y[_1_]]

Brian wrote:
> My friend that flys 737's for Alaska Airlines says that he hits that
> autopilot button 50 feet off of the ground on Take off and takes the
> controls back 50 feet over the ground on landing.
>
> I can't vouch for how accurate it is, but it would surprise me to be
> fairly accurate.
>

I've heard the same from my local bus drivers.

[comanche driver]

depends, weather, complexity of departure and arrival route, and my
attitude. sometimes I turn it on at 500 ft and off at 100 ft. sometimes I
hand fly the whole trip.
the only requirement that we have is that above 290 it must be on for RVSM
rules.

R. Burns

"B A R R Y" > wrote in message
...
> Brian wrote:
>> My friend that flys 737's for Alaska Airlines says that he hits that
>> autopilot button 50 feet off of the ground on Take off and takes the
>> controls back 50 feet over the ground on landing.
>>
>> I can't vouch for how accurate it is, but it would surprise me to be
>> fairly accurate.
>>
>
> I've heard the same from my local bus drivers.

[Mxsmanic]

Robert M. Gary writes:

> If he's maintaining CAT III currency he's getting at least some auto
> lands as well.

How widespread is Cat III equipment, on the ground and in the air?

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[Robert M. Gary]

Mxsmanic wrote:
> Robert M. Gary writes:
>
> > If he's maintaining CAT III currency he's getting at least some auto
> > lands as well.
>
> How widespread is Cat III equipment, on the ground and in the air?

Most of the major carriers have CAT III equipment and most major
airports have at least one ILS with CAT III. You wouldn't get much AM
flying done near places like Sacramento and Seattle in the winter
without CAT III since the fog often reduces visibility well below
standard ILS mins.

-Robert

[Michael Nouak]

Hi mxs,

the topic question being rather general, the general answer would be: most
of it. However, I suspect you were looking for a more detailed answer so I
hope you don't mind if I give you my 2 cts on that.

My background: I'm an FO on FK70/FK100.
http://www.airliners.net/open.file/1096746/L/

First of all, and I know this is prolly gonna cause a ruckus, but flying an
airliner for a living is not:

> the fun

it's work. It's fun work (I wouldn't wanna have any other job) but it's work
nonetheless. If I wanna fly for fun, I'll go to the US and buy a 50-hr block
on a C172. Having established that airlining is work, I obviously wanna make
as much money as possible while working as little as possible, which is one
of many reasons to use the A/P as much as possible.

Let's start with the take-off:

Minimum A/P engagement altitude on the Fokkers is 35 ft AGL. The lowest I've
ever engaged it was prolly just above 1500' AGL, but I usually don't engage
it until about 4-5000'. I don't think I've ever waited as far as 10k'. Most
pilots in my company do it that way, but there are a few who will engage the
A/P ASAP.

There are several reasons for dong that way, some of which are: using A/P
frees the PFs eyes for system monitoring during one of the most critical
phases of flight; if one engine decides to fly somewhere other than the
intended destination the A/P will absolutely make sure the rest of the a/c
flies where it's supposed to; the A/P does a much better job of flying the
required track and profile than a human.

This last reason is actually the reason why I like to do things the way I do
them: While passing Thrust Reduction and Acceleration Altitudes, the A/P
will follow the Flight Director (F/D) religiously, which, under some
conditions, may mean a fairly aggresive lowering of the nose. With some of
the Self-Loading Freight being rather sensitive with regards to having their
stomachs in their chest cavity I like to smoothen that part out a bit. With
the engines on Fokkers being so close together the resulting yaw in an E/O
case is small enough that it doesn't become a handful to fly, so that
shouldn't be a problem anyway.

There are some pilots who like to hand-fly the departure through 10k' or
more. Usually those will be fairly new ones, who will argue that they need
to practice hand-flying. However, the flying experience gained from staring
at a screen and moving a yoke around such that the F/D bars stay centered is
about the same as that gained while staring at a screen and moving the mouse
around such that the crosshairs is over the opponent in an ego shooter game.
No really, hand-climbing to the top of climb doesn't sharpen flying skills
one bit and compared to the A/P is inaccurate too. Better to use the A/P and
do some sight-seeing or read the paper. Or monitor the system.

Cruise:

Having the A/P off in the cruise, whether by choice or by malfunction, keeps
you out of RVSM airspace (starts at FL290), which of course means increased
fuel consumption, which of course means less money made on the flight.
Obviously, this is a major reason for having the A/P on during cruise
flight, since losing as little money as possible is the main goal of any
airline. Though I think the goal used to be to actually make money? Fancy
that!

Seriously, though: I had the A/P fail on me a couple of months ago with me
as PF during climb-out from Stockholm Arlanda (ESSA). We were limited to
FL270 where the planned alt had been FL350. Fortunately we had 30 mins extra
fuel on board, which saved us from having to divert. Also, after about 2
hours or so of staring at the PFD, I noticed myself getting a tad fatigued.
Plus of course I had less mental capacity available for system monitoring
than I would have had had the A/P been available. So there are valid reasons
other than purely commercial ones for having the A/P on during cruise.
Imagine having it fail half-way during a trans-atlantic flight!

Oh yeah: I didn't gain any flying experience either from keeping the needles
centered. And I didn't get to read my newspaper.

Approach and Landing:

If you guessed that the A/P is much better at keeping the needles centered
while riding down an ILS beam you guessed right. Which is the reason why a
few pilots leave it on until 80' AGL which is the minimum use height during
normal precision approaches (Auto-Lands (A/L) are a special case). However,
most people, including myself, normally switch it off somewhere between
2000' and 1000'. There's no good reasons for that really; I guess this is
where the fun flyer breaks out in us!

Visual approaches offer a bit more opportunity for hand-flying but are
unfortunately very rarely granted here in Europe. Even so, most of the
approach is flown on A/P, which is then normally disconnected somewhere on
downwind or base. Why? Because the A/P is much better at holding ALT and HDG
than a human. With HDG 360 selected the A/P doesn't slowly drift to 002,
then realize it's off a bit, correct to 358, then to 360 again, then drift
away again to 357 and so forth. It holds HDG 360. The same goes for
altitude, although holding altitude manually is very easy in the Fokkers.
Much easier than in C172s anyway.

A/Ls: at least 3 A/Ls have to be performed in a six-month period to stay
current. Of course there may be more if the weather so demands. On the
Fokkers an A/L ends latest during Roll-Out when the A/P is disconnected
while breaking to below 60 knots. BTW, breaking out at 50' and seeing a
runway in front of you looks pretty cool.

No newspaper reading during the landing. Honest.

Let me try to answer a couple more questions:

> parts, such as takeoff and landing? Systems exist to fully
> automate both, but are such systems routinely installed and used

Yes and Yes.

> today? Do airlines have policies that require or prohibit the use of
> such systems under normal conditions?

Here, it is recommended to make the most use of all available equipment, and
I believe that's the same for most large airlines.

Sorry for being long-winded. I hope it's what you were looking for


--
Michael Nouak
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[Mxsmanic]

Michael Nouak writes:

> Oh yeah: I didn't gain any flying experience either from keeping the needles
> centered. And I didn't get to read my newspaper.

So you're saying that even flying the aircraft yourself is essentially
just a matter of watching the needles? Is this because you must stay
exactly right on the flight path? I take it there is very little
margin for pilot discretion on commercial flights.

> BTW, breaking out at 50' and seeing a runway in front of you looks
> pretty cool.

I agree. It validates one's confidence in technology.

> Yes and Yes.

Long years ago I came into CDG on a flight from LAX and noticed that
the landing was glassy smooth despite essentially zero visibility (in
fact, I didn't know we were on the ground until I saw buildings in the
distance rushing by outside the window). At the time I thought it was
just a very good pilot. Now I suppose that it was actually an
autolanding--the best pilot of all.

> Here, it is recommended to make the most use of all available equipment, and
> I believe that's the same for most large airlines.
>
> Sorry for being long-winded. I hope it's what you were looking for

I don't mind long-winded. Thank you for the very detailed reply,
that's exactly the kind of reply I was hoping for.

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[John Gaquin]

"Mxsmanic" > wrote in message

> How much of an average commercial flight on a large airline and
> aircraft today is done automatically,

I used to routinely hand fly to 20-25K on departure, and from 10K down on
arrival, just for the enjoyment of it. There were some exceptions, such as
an approach in serious weather, or at the end of a ten hour flight, when
everyone is already tired. Better to let the machine do it, and just
monitor.

[Scott Skylane]

Michael Nouak wrote:

/snip/With HDG 360 selected the A/P doesn't slowly drift to 002,
> then realize it's off a bit, correct to 358, then to 360 again, then drift
> away again to 357 and so forth. It holds HDG 360. The same goes for
> altitude,
/snip/

Well, Micheal, perhaps if you hand flew the aircraft a little more
often, this wouldn't be such a challenge.

Happy Flying!
Scott Skylane

[Mxsmanic]

John Gaquin writes:

> I used to routinely hand fly to 20-25K on departure, and from 10K down on
> arrival, just for the enjoyment of it. There were some exceptions, such as
> an approach in serious weather, or at the end of a ten hour flight, when
> everyone is already tired. Better to let the machine do it, and just
> monitor.

From the way people talk, I get the impression that it may be more fun
flying a simulator than the real aircraft today, since the simulator
offers more challenges and is far more forgiving if one fails to meet
the challenge. I suppose if the simulator run is required to keep
one's job or license, it might be stressful, but surely there is
simulator time available for "fun" or at least discretionary use for
pilots?

As a passenger I always liked takeoff and landing, with cruise being
okay (as long as it didn't last for hours and hours). Nowadays,
though, with all the overhead of air travel, it's just not worth
flying for the short experience of takeoff and landing. I have the
impression that the situation is similar for pilots, with much of
normal flying reduced to pressing buttons and turning dials.

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[John Gaquin]

"Mxsmanic" > wrote in message
>
> From the way people talk, I get the impression that it may be more fun
> flying a simulator than the real aircraft today,

I don't think I would agree with you on that, although some might. De
gustibus.....

> ....but surely there is
> simulator time available for "fun" or at least discretionary use for
> pilots?

Those simulators probably cost way more to operate than a small plane, and
there ain't nothin' free in aviation. :-(

[Mxsmanic]

John Gaquin writes:

> Those simulators probably cost way more to operate than a small plane, and
> there ain't nothin' free in aviation. :-(

I meant in comparison with the large commercial aircraft that they
simulate. Flying a small plane wouldn't be the same experience,
although some might prefer it.

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[Capt.Doug]

>"Scott Skylane" wrote in message
> Well, Micheal, perhaps if you hand flew the aircraft a little more
> often, this wouldn't be such a challenge.

Depends on the stability of the aircraft in question.

D.

[Michael Nouak]

First of all, sorry, mxs, for the late reply but I've been working...

"Mxsmanic" > schrieb im Newsbeitrag
...
> Michael Nouak writes:
>
>> Oh yeah: I didn't gain any flying experience either from keeping the
>> needles
>> centered. And I didn't get to read my newspaper.
>
> So you're saying that even flying the aircraft yourself is essentially
> just a matter of watching the needles? Is this because you must stay
> exactly right on the flight path? I take it there is very little
> margin for pilot discretion on commercial flights.

Let me start again with the short answer, which is, surprise: yes

And now a bit more long-windedness:

To be sure, commercial a/c will fly happily on full manual, i. e. with A/P,
F/D and A/T off. There is no problem flying visual patterns until your tanks
are dry if you're so inclined. You could navigate by pilotage if you wanted
to. You could take off from St. Louis and say to yourself: "If'n I jess
follow that thar rivah down south, b'gosh at some point I must be in
Nawlins." OK, so my twang is pretty bad (hey, I'm just a furrinah :-)), but
I think you get the point.

Unfortunately, that's not what airlining is about. In a commercial
environment, it is your job, as a pilot, to fly SIDs, STARs, and Airways
with best possible precision. The reasons for that precision requirement are
quite numerous. As far as SIDs and STARs are concerned, more often than not
the main reason is noise abatement. Obstacle avoidance is, of course,
another good one! On Airways, the reasons may be to make ATCs job of
providing separation easier; to stay clear of prohibited airspace; etc.

Obviously, best possible precision is achieved by the A/P, which happens to
be linked to the Flight Management System (FMS), which calculates the
required track. However, when flying manually, whether by choice or
malfunction, the next best level of precision is provided by the F/D, which
is also linked to the FMS. And that's what I meant by "keeping the needles
centered." It's my job to fly the required track as accurately as possible,
and I do that best by following the F/D. If the F/D fails, the next best
level of precision is provided by the Navigation Display, which shows, among
other things, the required track, an airplane symbol, the heading I'm flying
and the track I'm flying. With both A/P and F/D inop, I would then try to
manipulate the controls such that the airplane symbol is over the track line
and the indicated track flown coincides with the required track.

I think you can see that a lot of equipment needs to fail to lower the best
possible precision to the level of pilotage.

With all that said, it is possible to deviate from the required track if
necessary. Best example, especially at this time of the year, would be if
you saw a TS (either visually or on weather radar) lying across your track.

A short note about A/Ls:

> Long years ago I came into CDG on a flight from LAX and noticed that
> the landing was glassy smooth despite essentially zero visibility (in
> fact, I didn't know we were on the ground until I saw buildings in the
> distance rushing by outside the window). At the time I thought it was
> just a very good pilot. Now I suppose that it was actually an
> autolanding--the best pilot of all.

During an A/L, the A/P will put the a/c down in the Touch-Down Zone, come
what may. I've seen A/Ls that were smooth as glass, and others that ended
with a pretty solid thump. I'm glad to report that the smoothest landings
I've seen were performed by either myself or my human colleagues!

Crews will usually elect to perform an A/L well before the weather is such
that it is an absolute requirement. With a reported ceiling of 250' and fog
patches, it makes little sense to hand-fly the approach, only to see that at
200', big surprise!, you're in a fog patch and have to go around. It would
also be rather difficult to explain to management.

HTH!

--
Michael Nouak
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[Mxsmanic]

Michael Nouak writes:

> As far as SIDs and STARs are concerned, more often than not
> the main reason is noise abatement.

I'm surprised that noise abatement is still an issue. Modern
high-bypass turbofans are very quiet compared to their turbojet
ancestors of a few decades ago.

I used to live directly beneath the approach path of a very large
airport and had aircraft flying over my house every few minutes on
most days, but I never even noticed any noise. However, some people
down the street in a retirement community constantly complained about
the noise. I'm not sure how they managed to hear it when I didn't.

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[Emily[_1_]]

Mxsmanic wrote:
> Michael Nouak writes:
>
>> As far as SIDs and STARs are concerned, more often than not
>> the main reason is noise abatement.
>
> I'm surprised that noise abatement is still an issue. Modern
> high-bypass turbofans are very quiet compared to their turbojet
> ancestors of a few decades ago.

I work for a manufacturer of high-bypass turbofans and they're still
extremely loud. I also live next to one of the busiest airports in the
country. Believe me, there's not much difference between old and new.

[Mxsmanic]

Emily writes:

> I work for a manufacturer of high-bypass turbofans and they're still
> extremely loud.

Turbojets are ear-splitting even from the observation decks from which
I used to watch them. Turbofans are hard to hear more than a few
hundred metres away. They may sound very loud, but that's only
because it's hard to remember how low turbojets were. Military
aircraft can serve as a good reminder of how loud engines can get (for
an extreme example, the SR-71 is a good test, with its turbojets that
cruise in afterburner).

> Believe me, there's not much difference between old and new.

How can you be so sure? There isn't much of the old around any more.

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[Montblack[_1_]]

("Emily" wrote)
> I work for a manufacturer of high-bypass turbofans and they're still
> extremely loud. I also live next to one of the busiest airports in the
> country. Believe me, there's not much difference between old and new.


Not sure if Honda's "GE-Honda" HF118 Turbofan Engine qualifies as
'high-bipass'
....it is extremely quiet.

On flybys at OSH, the HondaJet sounded like a handheld hairdryer, left
running across the room - on medium.

"The HF118 produces 1,700 lbf of thrust, and meets ICAO Stage IV noise
requirements. The sole application as of 2006 is for the HA-420 HondaJet."

http://en.wikipedia.org/wiki/Turbofan
Learning about high-bypass turbofans.... <g>


Montblack

[Morgans[_2_]]

"Montblack" > wrote

> On flybys at OSH, the HondaJet sounded like a handheld hairdryer, left
> running across the room - on medium.
>
> "The HF118 produces 1,700 lbf of thrust, and meets ICAO Stage IV noise
> requirements. The sole application as of 2006 is for the HA-420 HondaJet."

It is also very important as to how the engine is installed, and the
attention given to intake and exhaust profiles.

The C-17, for example, is about the quietest transport I have ever heard.
When you look at the intake, there is something unusual to it. All over on
the inside of the intake, there a hundreds if not thousands of small (1/8th
inch ?) holes, drilled in specific patterns. They are said to have a large
effect on absorbing the shrill noise coming from the compressor, and leaving
out the front of the engine. I would bet that there are some tricks to the
Honda ducting and installation, also.

It also occurs to me that the engine being above the wing would block some
of the noise from reaching the ground. Anyone know about that?
--
Jim in NC

[Mxsmanic]

Montblack writes:

> Not sure if Honda's "GE-Honda" HF118 Turbofan Engine qualifies as
> 'high-bipass'
> ...it is extremely quiet.

You can usually recognize high-bypass fans because they are quite fat
in front (because of the large fan), and often the nacelle has two
salient parts, a fat part in the front and a thinner part in the back.

They are quieter because the flow of air from the fan acts as a buffer
between the noisy flow from the exhaust and the surrounding air. They
are also more efficient than turbojets at high subsonic speeds. I
think there is at least one supersonic turbofan design, but I don't
know to what extent they are used for this in production aircraft.

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[Bush[_1_]]

I have jump seated on many carrierst where the autopilot is engaged at
700 msl, blown through altitudes on the 'baby' dc-9,
I Love to fly and usually hand-fly one leg each day. You can tell
when drinks have been served since people start using the can.

Bush

On Wed, 30 Aug 2006 20:01:34 +0200, Mxsmanic >
wrote:

>How much of an average commercial flight on a large airline and
>aircraft today is done automatically, via autopilot, autoland, and so
>on? Including takeoff and landing. I know that the bulk of a flight
>is on autopilot, which makes sense since autopilots are good at flying
>planes and that's lots of hours to sit holding a yoke, but what about
>the fun parts, such as takeoff and landing? Systems exist to fully
>automate both, but are such systems routinely installed and used
>today? Do airlines have policies that require or prohibit the use of
>such systems under normal conditions? I've heard that in cruise
>flight, at least, airlines want their pilots to stay on autopilot as
>much as possible, to save fuel.

[Mxsmanic]

Bush writes:

> I have jump seated on many carrierst where the autopilot is engaged at
> 700 msl, blown through altitudes on the 'baby' dc-9,
> I Love to fly and usually hand-fly one leg each day. You can tell
> when drinks have been served since people start using the can.

Do you have indicators in the cockpit that tell you when the toilets
are being used??

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[Jay Beckman]

"Mxsmanic" > wrote in message
...
> Bush writes:
>
>> I have jump seated on many carrierst where the autopilot is engaged at
>> 700 msl, blown through altitudes on the 'baby' dc-9,
>> I Love to fly and usually hand-fly one leg each day. You can tell
>> when drinks have been served since people start using the can.
>
> Do you have indicators in the cockpit that tell you when the toilets
> are being used??

No but there's a trim wheel that will start running when people begin to
move toward the rear of the cabin to use the lavatories.

Jay B