Question about the Airbus planes

In article ,
John Smith wrote:

Mike Ash wrote:

That is indeed ridiculous.

Even more funny is that those Airbus bashers don't seem to realize that
a certain Boeing Dreamliner, should it ever fly, is built with a much
higher percentage of plastic parts than any Airbus.

It didn't occur to me that they would be Boeing partisans. I just
figured they were anti-composites. If they are Boeing fans then that
does indeed make it that much funnier.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

"Brian Whatcott" wrote in message
...
Private wrote:
"a" wrote in message
...
One has no idea how true this is, but for what it's worth, read on:.

snip

More at

http://www.globalresearch.ca/index.p...t=va&aid=14025

Happy landings,



Dear Anonymous Poster,

the level of engineering insight of this URL is typified by this
paragraph:
"We do not know if Air France Flight 447 was brought down by a lightning
storm, a failure of speed sensors, rudder problems or pilot error. What
we do know is that its plastic tail fin fell off and the plane fell almost
seven miles into the ocean killing everyone aboard."

If you don't realize the level of insight offered in this paragraph,
should you be spreading it?


IMHO the quoted passage is a fair statement of what we currently suspect,
hopefully further investigation will reveal more complete information.

The link was offered to stimulate thought and discussion and with the
qualifier "One has no idea how true this is, but for what it's worth, read
on:"

All pilots are (as always) encouraged to apply their own knowledge and
experience to form their own conclusions.

Happy landings,

"Mike Ash" wrote in message
...
In article ,
Brian Whatcott wrote:

Private wrote:
"a" wrote in message
...
One has no idea how true this is, but for what it's worth, read on:.

snip

More at

http://www.globalresearch.ca/index.p...t=va&aid=14025

Happy landings,

snip
(And yes, I realize that there are certain differences between building
a 600-pound glider and a 200,000-pound airliner, and between engineering
something to be safe enough to carry a single dare-devilish pilot and
carrying hundreds of paying passengers. But four decades ought to be
enough to figure out how it works for the latter, and indeed things are
moving that way.)

snip

I do not disagree with much of your post, and also have personally enjoyed
many happy hours flying glass gliders and powered aircraft, but feel
compelled to submit that in addition to the obvious weight differences, most
gliders live in a (UV free) trailer or hanger, and IMHE few have accumulated
over 5000 hours (500-2000 hrs is more average) vs. 50,000 hours for
airliners. (I once flew in a 737-200 that had 70,000 hrs and a similar
number of cycles.) On most small powered and glider glass aircraft the
vertical stab is formed as an integral part of the fuselage vs. the airliner
where the weak point of the assembly seems to be the point of attachment to
the fuselage. I suspect you will also agree that in addition to the
increased loading and much higher speeds, the consequence of structural
failure of a commercial aircraft carrying large numbers of passengers is
greater than that of a much slower glider carrying 1 or 2 flyers who are
probably also wearing parachutes.

The real point of the article was that the materials technology, service
expectations and proper inspection procedures seem to still be under
development and that we still have much to learn. Older glass gliders often
display obvious deterioration of at least the gel coat and crashes have been
caused by structural failure or lightning strikes.

Happy landings,

Mike Ash wrote:

It didn't occur to me that they would be Boeing partisans.

Look at the subject ;-)

While I certainly distance myself from any of this sensationalist
speculation, and do not in any way join the Airbus detractors, I do think
the apparent similarity of the vertical stabilizer separation in the two
accidents is worthy of investigation. I am also fully confident that it
will be investigated, and determined as to whether the similarity is only
an apparent one or not. This is significant even if we never determine
what its contribution may have been in the causality of the Air France
accident.

In article ,
"Private" wrote:

"Mike Ash" wrote in message
...
In article ,
Brian Whatcott wrote:

Private wrote:
"a" wrote in message
...
One has no idea how true this is, but for what it's worth, read on:.

snip

More at

http://www.globalresearch.ca/index.p...t=va&aid=14025

Happy landings,

snip
(And yes, I realize that there are certain differences between building
a 600-pound glider and a 200,000-pound airliner, and between engineering
something to be safe enough to carry a single dare-devilish pilot and
carrying hundreds of paying passengers. But four decades ought to be
enough to figure out how it works for the latter, and indeed things are
moving that way.)

snip

I do not disagree with much of your post, and also have personally enjoyed
many happy hours flying glass gliders and powered aircraft, but feel
compelled to submit that in addition to the obvious weight differences, most
gliders live in a (UV free) trailer or hanger, and IMHE few have accumulated
over 5000 hours (500-2000 hrs is more average) vs. 50,000 hours for
airliners. (I once flew in a 737-200 that had 70,000 hrs and a similar
number of cycles.) On most small powered and glider glass aircraft the
vertical stab is formed as an integral part of the fuselage vs. the airliner
where the weak point of the assembly seems to be the point of attachment to
the fuselage. I suspect you will also agree that in addition to the
increased loading and much higher speeds, the consequence of structural
failure of a commercial aircraft carrying large numbers of passengers is
greater than that of a much slower glider carrying 1 or 2 flyers who are
probably also wearing parachutes.

All fine points. I understand that the circumstances are greatly
different (thus my parenthetical above), but it seems that 40 years
ought to be enough to move from the one to the other. And indeed, it
seems that both Airbus and Boeing think this way as well.

The real point of the article was that the materials technology, service
expectations and proper inspection procedures seem to still be under
development and that we still have much to learn. Older glass gliders often
display obvious deterioration of at least the gel coat and crashes have been
caused by structural failure or lightning strikes.

Gel coat deterioration is largely inconsequential, as it's not
structural and can be easily replaced. (Obviously it's not
"inconsequential" for the poor glider owner who has to pay five figures
for a refinish, but in terms of maintenance it's easy to spot and a
known quantity for repair.)

The lightning strike angle is an interesting one. I assume you're
referring to that ASK-21 which exploded over the UK a few years back,
and which we've seen some posts about from the passenger recently. I'm
not aware of another such incident, but that's probably more because
gliders are fair-weather beasts, not because they're usually immune to
lightning. Are there any other incidents you know of?

As for the structural failure angle, my (admittedly highly limited)
understanding is that there basically isn't any other than that
resulting from exceeding design limits or from manufacturing defects. My
club has an Open Cirrus which is over 40 years old and it's built like a
tank, and by all indications every bit as strong right now as it was
when it was built. My understanding is that this is the norm for
composite construction, as long as it's properly protected from the
elements. An important thing is that it doesn't really fatigue the way
metal does. Let's not forget that metal fatigue killed a bunch of
airline passengers in the 50s and remains a significant (and
occasionally deadly) concern today.

No doubt there is much to learn, and maybe the Airbus was improperly
designed, but my point is simply that a knee-jerk rejection of all
composites (which is what the article seemed to be trying to do with its
pejorative use of the word "plastic") is not the way to go.

Again, my knowledge on the subject is quite limited, so if I'm wrong
about any of the above, or just missing further important information, I
would very much appreciate any correction!

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

Mike Ash wrote:
I particularly enjoy the derisive use of the word "plastic" to describe
the vertical stabilizer. As an owner of a composite aircraft, I can tell
you that I much prefer "plastic" to metal when given the choice. Yeah,
when you exceed its strength it fails in a completely unforgiving
manner, but composites make it a *lot* harder to get to that point in
the first place.

Perhaps there really is an engineering deficiency here, but to think
that it's the fault of the material itself and that airliner engineering
should just ignore new materials technology and stick to good ol'
aluminum forever is silly. Glider makers figured out how great
composites were forty years ago, it's about time for the rest to catch
up too.

(And yes, I realize that there are certain differences between building
a 600-pound glider and a 200,000-pound airliner, and between engineering
something to be safe enough to carry a single dare-devilish pilot and
carrying hundreds of paying passengers. But four decades ought to be
enough to figure out how it works for the latter, and indeed things are
moving that way.)


Gliders fly at lower altitudes, at lower speeds, in good weather
conditions...

Airliners fly in high altitude, high speed, low temperature, in
thunderstorms...

How good is composite when lightning strikes? Doesn't is explode or
something? I don't think it will conduct electricity, does it?

Please see that as questions, I really don't know much and I'm
wondering. I'm not trying to reduce your opinion in anyway.

Tom

"Mike Ash" wrote in message
...
snip
something to be safe enough to carry a single dare-devilish pilot and
snip
Gel coat deterioration is largely inconsequential, as it's not
structural

How do we know for sure?

snip
As for the structural failure angle, my (admittedly highly limited)
understanding is that there basically isn't any other than that
resulting from exceeding design limits or from manufacturing defects.

EXACTLY my point.

snip
No doubt there is much to learn, and maybe the Airbus was improperly
designed, but my point is simply that a knee-jerk rejection of all
composites (which is what the article seemed to be trying to do with its
pejorative use of the word "plastic") is not the way to go.

Again, my knowledge on the subject is quite limited, so if I'm wrong
about any of the above, or just missing further important information, I
would very much appreciate any correction!


I think we are in substantial agreement, I particularly liked your original
reference to "a single dare-devilish pilot" and am reminded of the final
words (and on his gravestone) of Otto Lilienthal.
http://en.wikipedia.org/wiki/Otto_Lilienthal
His statement "Sacrifices must be made" pretty much sums up the history of
all aviation development, during which most advances have been accompanied
by the loss of (lots of) both blood and money.

IMHO, The use of the term 'plastic' is probably improper and certainly
overly general but it is common usage, and while I do agree that precise
language is an important goal, I try not to get too fixated on semantics.

Composites offer significant opportunities for improved aircraft
performance, but the use of these materials is complicated by the
variability of the materials and difficulty of quality control.in both
manufacturing and maintenance. It seems that better inspection procedures
for QC need to be developed and implemented and this will be of increased
importance as composite use increases and the fleet ages. We went through a
similar period in the development of metal airframes.

Happy landings,

In article ,
"Private" wrote:

I think we are in substantial agreement, I particularly liked your original
reference to "a single dare-devilish pilot" and am reminded of the final
words (and on his gravestone) of Otto Lilienthal.
http://en.wikipedia.org/wiki/Otto_Lilienthal
His statement "Sacrifices must be made" pretty much sums up the history of
all aviation development, during which most advances have been accompanied
by the loss of (lots of) both blood and money.

Yes, it seems to me that we are in agreement as well. How unusual.

IMHO, The use of the term 'plastic' is probably improper and certainly
overly general but it is common usage, and while I do agree that precise
language is an important goal, I try not to get too fixated on semantics.

Normally I would consider it to be completely unimportant. However in
this particular case, it's clearly being used as a pejorative. I don't
care all that much about his use of the word "plastic", it's merely
indicative of the overall attitude that composites are bad and people
who use them are stupid. In other words, "plastic" is a symptom, not the
disease. I've heard glider people refer to composite aircraft as
"plastic" from time to time and that doesn't bother me at all, because
the intent is not the same.

Composites offer significant opportunities for improved aircraft
performance, but the use of these materials is complicated by the
variability of the materials and difficulty of quality control.in both
manufacturing and maintenance. It seems that better inspection procedures
for QC need to be developed and implemented and this will be of increased
importance as composite use increases and the fleet ages. We went through a
similar period in the development of metal airframes.

The incremental use of composites in airliners, starting with small bits
here and there and working up, seems like the proper way to do things
here. I don't expect, or want, the airline industry to drop aluminum and
start doing everything in composites. An evolutionary approach as is
being done now will get us there in the end with a minimum of surprises.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

In article ,
Tom Duhamel wrote:

Gliders fly at lower altitudes, at lower speeds, in good weather
conditions...

Airliners fly in high altitude, high speed, low temperature, in
thunderstorms...

Don't think airliners fly higher. It's true that *on average* they do,
and they certainly collect *vastly* more time at FL360 than gliders do,
but gliders *do* collect time there. The current glider altitude record,
set in a composite glider, is over 50,000ft. I don't think low
temperatures or pressures have been seen to do anything bad to the
structure. A fellow did tell me once that a rapid descent can do bad
things to the gelcoat due to the temperature change, but that's a
separate issue, and I don't know if an airliner would even use that sort
of coating.

For speeds, that's really just a matter of increased structural strength
and stiffness, which means using more stuff or different shapes. The
question is how the composites tolerate load, which is well known. They
won't change their characteristics suddenly just because they're moving.

How good is composite when lightning strikes? Doesn't is explode or
something? I don't think it will conduct electricity, does it?

This one is a completely open question to me. No, they don't conduct
electricity as far as I know. In the one famous case of a glider getting
hit by lightning, the lightning traveled along metal control rods. The
rods superheated the air inside the wings, blowing the glider to bits.
Obviously this is not a desirable outcome for an airliner carrying 300
people and no parachutes. I can only assume that the smart engineers
working on this stuff have figured out a way to stop this from
happening, but I have no idea at all what that way would be.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon