Jet jocks and airliner drivers?

Dudley, Bertie, Bob Moore, Capt. Doug...


On my recent viewing of the A380 low and slow passes over some P&W
locations, I remarked how quiet the airplane was. During these passes
the aircraft was noticeably pitched up (maybe 150 knots?), and
slightly "dirty", just as the far simpler craft I usually fly might be
in a similar "slow flight" situation. I've been told by P&W employees
that the plane was loaded up with ballast, and far from light.

The most common remark I get from non-pilots on the lack of noise is
"he was at idle", as they compare it to a plane descending. My
response is that the 380 was maneuvering and maintaining altitude,
which would require more than idle power, maybe a lot more, just like
a smaller craft being flown in it's own version of slow flight.

Am I thinking along the correct lines, that an airliner at a decent
weight would require more than idle power to maneuver and maintain a
constant altitude while slow? I have zero jet time, but this would
only make sense. The Pratt guys agree with me, but they haven't flown
airliners either.

Thanks!

B A R R Y wrote:
Dudley, Bertie, Bob Moore, Capt. Doug...


On my recent viewing of the A380 low and slow passes over some P&W
locations, I remarked how quiet the airplane was. During these passes
the aircraft was noticeably pitched up (maybe 150 knots?), and
slightly "dirty", just as the far simpler craft I usually fly might be
in a similar "slow flight" situation. I've been told by P&W employees
that the plane was loaded up with ballast, and far from light.

The most common remark I get from non-pilots on the lack of noise is
"he was at idle", as they compare it to a plane descending. My
response is that the 380 was maneuvering and maintaining altitude,
which would require more than idle power, maybe a lot more, just like
a smaller craft being flown in it's own version of slow flight.

Am I thinking along the correct lines, that an airliner at a decent
weight would require more than idle power to maneuver and maintain a
constant altitude while slow? I have zero jet time, but this would
only make sense. The Pratt guys agree with me, but they haven't flown
airliners either.

Thanks!

I'm sure Moore is better qualified to answer you on the big stuff and
this crate is bigger than anything I've even ridden in as a passenger,
but my guess is that you are correct. If the aircraft was maintaining
altitude it would most certainly have power applied and probably quite a
lot of power. I will assume the engines on this bird are quieted down
somewhat as well, and airspeed with something this large can be deceiving.
The positive pitch angle on the fuselage would be normal depending on
several factors.
It's a monster!!! :-)

--
Dudley Henriques

On Thu, 04 Oct 2007 20:35:02 -0400, B A R R Y
wrote:

Dudley, Bertie, Bob Moore, Capt. Doug...


I'm none of them, but anyway...

Here's an excerpt from http://www.airbus.com/en/aircraftfamilies/a380/
about A380's noise levels:

"
Low-noise characteristics have been a major design driver for the
A380. As a result the aircraft is significantly quieter than other
large aircraft and offers substantial margins in relation to the
latest (ICAO Stage 4) noise limits. producing half the noise energy at
take off and cutting the area exposed to equivalent noise levels
around the airport runway by half.

In addition to meeting international regulations, the A380 also
presents a significant practical advantage over existing large
aircraft by minimising operating constraints arising from the most
stringent local noise regulations, such as the Quota Count (QC) system
at London airports. Being virtually free from noise curfew, the A380
offers greater operational flexibility to airlines and their
passengers while minimising the noise impact on the airport
neighbourhood at the same time.

This noise levels reduction has been achieved through the optimisation
of the engines, nacelles and airframe. In addition, the A380 is
equipped with an innovative function that enables the Flight
Management System (FMS) to be programmed with departure tracks that
are optimised for noise as well as performance. These allow the
aircraft to reduce the take off noise while taking into account actual
aircraft parameters and ambient conditions.

But the A380 is not only the quietest aircraft on the outside. The
A380 cabin is the quietest cabin in the sky. Reducing cabin noise
levels increases passenger comfort and well-being, and is an important
factor in limiting the fatigue normally associated with long haul
travel. Passengers that have flown in the A380 have confirmed initial
testing, which indicated the A380 cabin to be significantly quieter
than today's largest aircraft, 'like stepping from a busy office into
a quiet restaurant.'

The A380 flight deck is also the quietest in the skies, improving
working conditions for the flight crew.

From an environmental perspective the application of new technology
and intensive research has enabled the A380 to combine the intrinsic
advantages of its larger capacity with much lower noise levels, when
compared to existing large aircraft.

The A380 sets a new standard in noise levels.
"

I guess they learned from the bad experience with Concorde.

- Tom

On Oct 4, 6:35 pm, B A R R Y wrote:
Dudley, Bertie, Bob Moore, Capt. Doug...

On my recent viewing of the A380 low and slow passes over some P&W
locations, I remarked how quiet the airplane was. During these passes
the aircraft was noticeably pitched up (maybe 150 knots?), and
slightly "dirty", just as the far simpler craft I usually fly might be
in a similar "slow flight" situation. I've been told by P&W employees
that the plane was loaded up with ballast, and far from light.

The most common remark I get from non-pilots on the lack of noise is
"he was at idle", as they compare it to a plane descending. My
response is that the 380 was maneuvering and maintaining altitude,
which would require more than idle power, maybe a lot more, just like
a smaller craft being flown in it's own version of slow flight.

Am I thinking along the correct lines, that an airliner at a decent
weight would require more than idle power to maneuver and maintain a
constant altitude while slow? I have zero jet time, but this would
only make sense. The Pratt guys agree with me, but they haven't flown
airliners either.

Thanks!

Barry,

The latest generation of high-bypass engines produce much lower noise
than older engines, mostly due to extensive research on ways to smooth
the airflow through the engine and baffle the combustion noise. Hush
kits were added to older engines to help them meet the new noise
control requirements (up to stage 3 now).

The Boeing 777 engines are very quiet as well, especially at lower
power settings. Even at high power settings, they make more of a high
pitched whine combined with a whooshing sound rather than the roar
that accompanies the low bypass engines found on 707's and B52s.

Dean

B A R R Y wrote in
:

Dudley, Bertie, Bob Moore, Capt. Doug...


On my recent viewing of the A380 low and slow passes over some P&W
locations, I remarked how quiet the airplane was. During these passes
the aircraft was noticeably pitched up (maybe 150 knots?), and
slightly "dirty", just as the far simpler craft I usually fly might be
in a similar "slow flight" situation. I've been told by P&W employees
that the plane was loaded up with ballast, and far from light.

The most common remark I get from non-pilots on the lack of noise is
"he was at idle", as they compare it to a plane descending. My
response is that the 380 was maneuvering and maintaining altitude,
which would require more than idle power, maybe a lot more, just like
a smaller craft being flown in it's own version of slow flight.

Am I thinking along the correct lines, that an airliner at a decent
weight would require more than idle power to maneuver and maintain a
constant altitude while slow? I have zero jet time, but this would
only make sense. The Pratt guys agree with me, but they haven't flown
airliners either.

Well, hopefully idle power ould bring you down! If the damned thing flew
around at idle all the time you'd never be able to land it.
Mind you, there's flight idle and ground idle. I don't know if the 380 has
flight idle al the time it's airborne or not, but even that's not usually a
lot of power (imagine limiting your idle to say, 1300 revs minimum in your
172 or whateve while ou were airborne and you have an idea)
They're getting much quieter nowadays.
They're not being given a lot of choice in the matter as restrictions grow.

Bertie

Thanks to all!


Barry

B A R R Y writes:

On my recent viewing of the A380 low and slow passes over some P&W
locations, I remarked how quiet the airplane was. During these passes
the aircraft was noticeably pitched up (maybe 150 knots?), and
slightly "dirty", just as the far simpler craft I usually fly might be
in a similar "slow flight" situation. I've been told by P&W employees
that the plane was loaded up with ballast, and far from light.

The most common remark I get from non-pilots on the lack of noise is
"he was at idle", as they compare it to a plane descending. My
response is that the 380 was maneuvering and maintaining altitude,
which would require more than idle power, maybe a lot more, just like
a smaller craft being flown in it's own version of slow flight.

Am I thinking along the correct lines, that an airliner at a decent
weight would require more than idle power to maneuver and maintain a
constant altitude while slow? I have zero jet time, but this would
only make sense. The Pratt guys agree with me, but they haven't flown
airliners either.

More than idle would be required, but not necessarily a lot more.

Remember also that the aircraft is further away than it looks, and modern
high-bypass turbofans can be remarkably quiet. Have you compared the A380
directly to other aircraft in similar configurations? If they are recent,
they are probably pretty quiet, too.

Tom L. writes:

I guess they learned from the bad experience with Concorde.

Or perhaps Airbus isn't the most objective source for information on the noise
levels from its own aircraft. I notice the article contains virtually no
actual numbers at all.

Mxsmanic wrote in
:

B A R R Y writes:

On my recent viewing of the A380 low and slow passes over some P&W
locations, I remarked how quiet the airplane was. During these
passes the aircraft was noticeably pitched up (maybe 150 knots?), and
slightly "dirty", just as the far simpler craft I usually fly might
be in a similar "slow flight" situation. I've been told by P&W
employees that the plane was loaded up with ballast, and far from
light.

The most common remark I get from non-pilots on the lack of noise is
"he was at idle", as they compare it to a plane descending. My
response is that the 380 was maneuvering and maintaining altitude,
which would require more than idle power, maybe a lot more, just like
a smaller craft being flown in it's own version of slow flight.

Am I thinking along the correct lines, that an airliner at a decent
weight would require more than idle power to maneuver and maintain a
constant altitude while slow? I have zero jet time, but this would
only make sense. The Pratt guys agree with me, but they haven't
flown airliners either.

More than idle would be required, but not necessarily a lot more.


You're an idiot and you don't fly.




Remember also that the aircraft is further away than it looks, and
modern high-bypass turbofans can be remarkably quiet. Have you
compared the A380 directly to other aircraft in similar
configurations? If they are recent, they are probably pretty quiet,
too.


Someone here has flown 'Busses with very high bypas engines and knows
exactly how much thrust is required to maintain slow, level, flight.

And it isn't you.


Bertie

Mxsmanic wrote in
:

Tom L. writes:

I guess they learned from the bad experience with Concorde.

Or perhaps Airbus isn't the most objective source for information on
the noise levels from its own aircraft. I notice the article contains
virtually no actual numbers at all.



Like they would mean anything to you.



Bertie