How much is autopilot on commercial flights today?

("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

"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

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.

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

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.

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??

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

"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