Question about the Airbus planes

I have posted here before because I like to get answers from experts
about aviation. I have been interested in the media reporting on the
Air France Flight 447 crash. More to the point, I'm curious if you
all think they are missing a bigger story.

The Airbus planes employ something called fly-by-wire technology. As
I understand it, that means the actuators that move the control
surfaces of the aircraft are triggered solely by electrical wiring.
They don't rely on a hydrolic system to move the surfaces based on the
moves of the control stick.

So as I'm hearing about flight 447, the thought crosses my mind that
if lightning hit the plane just right, would it be possible for that
to send the wrong signals to the control actuators? Perhaps pushing
them in different directions and locking them there as the electric
connections failed due to the lightning strike? Or at the very least
severing the electric connections by frying the wires and making it
impossible for the crew to control the airplane. I know it has
redundant systems and lots of insulation on the wires, but it seems to
me that such an all-electric system makes a problem like this possible
where a hydrolic system does not.

I keep hearing aviation experts saying that a lightning strike
wouldn't bring down a plane of this size. I also seem to recall NASA
declaring that foam strikes wouldn't damage the shuttle enough to
cause it to break up on re-entry. I'm just wondering if fly-by-wire
has an undocumented (or unannounced) fatal flaw.

What do you think?

wrote:

I have posted here before because I like to get answers from experts
about aviation. I have been interested in the media reporting on the
Air France Flight 447 crash. More to the point, I'm curious if you
all think they are missing a bigger story.

The Airbus planes employ something called fly-by-wire technology. As
I understand it, that means the actuators that move the control
surfaces of the aircraft are triggered solely by electrical wiring.
They don't rely on a hydrolic system to move the surfaces based on the
moves of the control stick.

The system still uses hydraulics to move the control surfaces.

So as I'm hearing about flight 447, the thought crosses my mind that
if lightning hit the plane just right, would it be possible for that
to send the wrong signals to the control actuators? Perhaps pushing
them in different directions and locking them there as the electric
connections failed due to the lightning strike? Or at the very least
severing the electric connections by frying the wires and making it
impossible for the crew to control the airplane. I know it has
redundant systems and lots of insulation on the wires, but it seems to
me that such an all-electric system makes a problem like this possible
where a hydrolic system does not.

Anything's possible, however nothing like that has ever shown up so far
on thousands of FBW aircraft that have been flying for over 20 years. It
has about a much credence as the plane being hit by falling debris from
space.

I keep hearing aviation experts saying that a lightning strike
wouldn't bring down a plane of this size. I also seem to recall NASA
declaring that foam strikes wouldn't damage the shuttle enough to
cause it to break up on re-entry. I'm just wondering if fly-by-wire
has an undocumented (or unannounced) fatal flaw.

Don't think so.

wrote in message
...
..

What do you think?

I think that you are engaging in meaningless speculation.

Vaughn

wrote in message
...
I have posted here before because I like to get answers from experts
about aviation. I have been interested in the media reporting on the
Air France Flight 447 crash. More to the point, I'm curious if you
all think they are missing a bigger story.

The Airbus planes employ something called fly-by-wire technology. As
I understand it, that means the actuators that move the control
surfaces of the aircraft are triggered solely by electrical wiring.
They don't rely on a hydrolic system to move the surfaces based on the
moves of the control stick.

So as I'm hearing about flight 447, the thought crosses my mind that
if lightning hit the plane just right, would it be possible for that
to send the wrong signals to the control actuators? Perhaps pushing
them in different directions and locking them there as the electric
connections failed due to the lightning strike? Or at the very least
severing the electric connections by frying the wires and making it
impossible for the crew to control the airplane. I know it has
redundant systems and lots of insulation on the wires, but it seems to
me that such an all-electric system makes a problem like this possible
where a hydrolic system does not.

I keep hearing aviation experts saying that a lightning strike
wouldn't bring down a plane of this size. I also seem to recall NASA
declaring that foam strikes wouldn't damage the shuttle enough to
cause it to break up on re-entry. I'm just wondering if fly-by-wire
has an undocumented (or unannounced) fatal flaw.

What do you think?

I have been wondering the same thing. I know our history with FBW seems
golden with respect to lightening strikes, but they were flying near a large
thunder storm. Seems regardless of our success with FBW, perhaps they were
the victim of some kind of mega strike that overwhelmed their systems. Our
experience with lightening has documented some very powerful and bizarre
behavior, this might be a first.

But even if true, it wouldn't necessarily suggest a fatal flaw in FBW. A
possible loss of control or structural integrity could be unrelated to the
FBW system, and perhaps a supposed mega strike could have condemned a
conventionally controlled aircraft just as easily.

"Tim" wrote:

I have been wondering the same thing. I know our history with FBW
seems golden with respect to lightening strikes, but they were flying
near a large thunder storm.

According to two separate sources that track lightning, there was none
within something like 100 miles of their planned course, so it isn't clear
that they were anywhere near lightning. It's simply speculation on the
part of some pundits.

James Robinson wrote:
"Tim" wrote:
I have been wondering the same thing. I know our history with FBW
seems golden with respect to lightening strikes, but they were flying
near a large thunder storm.

According to two separate sources that track lightning, there was none
within something like 100 miles of their planned course, so it isn't clear
that they were anywhere near lightning. It's simply speculation on the
part of some pundits.

And those same two separate sources admit they don't have great coverage
in the Atlantic in that area, so I don't think that data point is any
more useful than the Air Comet flight that claimed they saw an "intense
flash of bright light." Their flight path was no closer than 2000 km
from the likely crash area of AF 447.

Given the actual data of satellite pics showing the continuous
convective buildups in that area, lightning in the area is certainly
plausible. Whether it actually touched the airplane, and if so whether
it led to a unrecoverable situation is certainly very questionable.

Clark wrote:

James Robinson wrote in
news:Xns9C20C3311F8C9wascana212com@ 94.75.244.46:

"Tim" wrote:

I have been wondering the same thing. I know our history with FBW
seems golden with respect to lightening strikes, but they were
flying near a large thunder storm.

According to two separate sources that track lightning, there was
none within something like 100 miles of their planned course, so it
isn't clear that they were anywhere near lightning. It's simply
speculation on the part of some pundits.


Do those sources track air-to-air or air-to-ground lightning? If they
are ground based then they only track air-to-ground and they will miss
all the air-to-air stuff. That might make just a wee bit of
difference...

They use satellites.

While that is a possibility the timing might suggest otherwise. The
malfunction reports that reported electrical and pressurization failures
came several minutes AFTER other serious malfunction reports. It is
possible the electrical and pressurization failures report was a RESULT of
an aircraft breakup.

wrote in message
...
I have posted here before because I like to get answers from experts
about aviation. I have been interested in the media reporting on the
Air France Flight 447 crash. More to the point, I'm curious if you
all think they are missing a bigger story.

The Airbus planes employ something called fly-by-wire technology. As
I understand it, that means the actuators that move the control
surfaces of the aircraft are triggered solely by electrical wiring.
They don't rely on a hydrolic system to move the surfaces based on the
moves of the control stick.

So as I'm hearing about flight 447, the thought crosses my mind that
if lightning hit the plane just right, would it be possible for that
to send the wrong signals to the control actuators? Perhaps pushing
them in different directions and locking them there as the electric
connections failed due to the lightning strike? Or at the very least
severing the electric connections by frying the wires and making it
impossible for the crew to control the airplane. I know it has
redundant systems and lots of insulation on the wires, but it seems to
me that such an all-electric system makes a problem like this possible
where a hydrolic system does not.

I keep hearing aviation experts saying that a lightning strike
wouldn't bring down a plane of this size. I also seem to recall NASA
declaring that foam strikes wouldn't damage the shuttle enough to
cause it to break up on re-entry. I'm just wondering if fly-by-wire
has an undocumented (or unannounced) fatal flaw.

What do you think?

...
.

What do you think?


Here is something I found interesting:
http://www.weathergraphics.com/tim/af447/

Kobra

Panic wrote:
While that is a possibility the timing might suggest otherwise. The
malfunction reports that reported electrical and pressurization failures
came several minutes AFTER other serious malfunction reports. It is
possible the electrical and pressurization failures report was a RESULT of
an aircraft breakup.

ACARS did not report a "pressurization failure." ACARS reported a cabin
altitude alarm. Although loss of pressurization could be one reason for
this alarm, another would be a fast descent and "catching the cabin" or
the outside altitude getting too close too fast to the cabin altitude.

Beware what you read in the press, they are taking raw data and either
misinterpreting it or trying to "simplify" it for their impression of
their reader's intelligence.

Exhibit A for this is the NY Times:

"A loss of cabin pressure could suggest a break in the fuselage, but
planes are built to withstand buffeting from a storm’s updrafts and
downdrafts. It could also be a consequence of an electrical failure, if
the plane’s air compressors stop working."

As if the A300 has electric air compressors! No western transport plane
flying today does, although the Boeing 787 will change that. Perhaps
the "reporters" should do a little fact checking and research about what
they are writing about.