Ships race to Air France wreckage

Reuters via National Post ^ | 2009-06-03 | Crispian Balmer

[Clive]

PARIS -- Brazilian and French navy vessels rushed on Wednesday to reach wreckage of an Air France flight that plunged into the Atlantic, but investigators warned the truth behind France's worst air disaster may never fully emerge.

The doomed Airbus was carrying 228 passengers and crew en route from Rio de Janeiro to Paris when it crashed into the ocean early on Monday after the pilot reported heavy turbulence.

Debris was sighted by a spotter plane more than 24 hours later about 745 miles (1,200 km) northeast of the Brazilian coastal city of Recife, and the Brazil navy has dispatched four navy ships with recovery equipment to the area.

France prepared to send a boat with an unmanned submarine aboard that can explore as deeply as 6,000 metres (19,680 ft) and will try to locate the Airbus's black boxes, which could shed light on the mysterious disaster.

Paul Louis Arslanian, the head of France's air accident investigation agency, said he was not totally optimistic that the black boxes would ever be recovered and said the probe might not reveal all the reasons behind the crash.

"I cannot rule out the possibility that we might end up with a finding that is relatively unsatisfactory in terms of certainty," Mr. Arslanian told reporters.

"But we will do our best to limit the uncertainty," he said.

A first report will be ready by the end of the month, with the investigation led by Alain Bouillard, who took charge of the probe into the crash of an Air France Concorde in 2000.

[r9etb]

The area of the crash was shown to have a massive line of thunderstorms at the time of the crash.

Yup.

[The Sons of Liberty]

I fit was a bomb, they probably wouldn’t have had time to send a distress signal.

[cvq3842]

Thanks.

[Alex Kida]

I don’t know about US Government spy satellites looking down on the surface of the earth might see but I suspect most everything that goes on is recorded for military defense. There is radar that also looks for unknown aircraft as part of defense.

Anybody know about what the Department of Defense, Air Force and other groups might know?

[Citizen Tom Paine]

The site search is rather simple for an old oceanographer. Tow 250KC side looking sonar in a search pattern until the major aircraft parts are found. Then launch a submersible with a reticulated arm and pick up what is required (small pieces) and to take close up pics of interesting items. Buoy the site and determine the GPS positions. Then hire a ship with heavy lift capabilities and get to work.

I doubt if they will find any bodies.

[CodeToad]

“Maybe, but I don’t think so.

Typically, that only happens when the jet was previously damaged and not repaired properly.”

Wrong. Airlines streer clear of thunderstorms because of the violent winds that exceed the aircraft’s structural limits. Where did you get the idea that “...only happens when the jet was previously damaged and not repaired properly”?

[the long march]

Agreed but so do terroists bombs. We discount things at our peril

[the long march]

Obviously a lightning strike ...../sarc

[CodeToad]

“Anybody know about what the Department of Defense, Air Force and other groups might know?”

Well, they don’t record everything as they don’t see everything. They can see what they want to for the most part, but global coverage 24x7 isn’t a reality.

There most likely would not have been any sensors looking in that area specific enough to see an aircraft break apart and crash. There are, however, sensors capable of looking for the wreackage now that the DoD knows there is a plane down in the area.

[Jewbacca]

Being a military pilot for 20 years.

The storm was ugly but not that bad.

[Gandalf_The_Gray]

Reticulated = Giraffe or Python (covered with a net like marking)

Articulated = having a joint or joints; jointed: an articulated appendage.

They have thirty days before the "Black Boxes" stop pinging, they'd better get a move on!

Regards,
GtG

PS I know you knew that but I just couldn't help myself.

[Gandalf_The_Gray]

Being a military pilot for 20 years.

The storm was ugly but not that bad.

I'll bet you never flew a "fly-by-wire" aircraft that was glued together from composites either. (They just don't build'em like they used too!)

Regards,
GtG

I don't fly commercial as much as I used to but I'd never get on an "AirBus".

[TalonDJ]

Posts over on airliners.net seemed to indicate that the three-or-four minute sequence of automated ACARS messages indicated some sort of electrical faults, followed by an autopilot disconnect, then ADIRU (air data inertial reference unit, I think) and standby instrument faults, then faults on the primary and one secondary flight computer, and finally an excessive cabin vertical speed warning that might indicate a depressurization. So whatever happened to AF447 wasn’t one massive failure like a Pan Am 103 or a TWA 800. Things failed over a span of at least four minutes, apparently in a cascade of increasing severity.

A sequence like that could have been an in air break up. Remember those indications are not indications of root problems but of the symptoms. Many things can cause autopilot disconnect. Same with the ADIRU. Both of those would indicate failures if the aircraft went had severe upset.

here is an example.
Planes rudder breaks off (there is not 'tail off indicate)
Extreme yaw shears an engine off.
electrical system loses the generator that was on that engine and registers an error
-- electrical error is sent out
The extreme yaw causes the autopilot to disconnect (it will do that)
-- autopilot error sent out
A wing comes off.
The standby indicator has lost contact with several systems it needs to function and
--it reports an error
The computers have lost contact with many systems and sensors. They go into a faulted state.
--they report errors
Plane is falling and tumbling. Cabin breaks open.
Cabin pressure drops suddenly. This is referred to as cabin Altitude. The result is that the cabin altitude reading just went 'up' by thousands of feet.
-- cabin altitude error is reported.


I am not saying this is the right sequence. But this is an example of how one thing (turbulence taking the rudder off) can register as a series of failures as things go down the tubes.

I am not familiar with this particular plane or how it's failures are reported but I have spent an number of years as an avionics engineer.

[TalonDJ]

True. And if there were a fire that affected the signals being sent to control actuators, that would perhaps show up as "turbulence."

Well fires would not do that to the signals themselves. But they still might cause things to look turbulent. Anyway, they were near storms so things WERE turbulent even if that was not what killed them.

[TalonDJ]

The storm was ugly but not that bad.

That is not what the 5 or 6 airline pilots I have heard call into talk shows in the last 2 days all said. One of the ones that I heard had actuall flown that route quite a bit. A thunder storm that is over 50kft high can cetainly take an airliner apart.

Most military aircraft are more solidly built.

[Jewbacca]

“that was glued together from composites either”

Some were, at least partially. Far too much duct tape.

[Moose4]

This is the quote from an avherald.com article about the faults yesterday:

“New information provided by sources within Air France suggests, that the ACARS messages of system failures started to arrive at 02:10Z indicating, that the autopilot had disengaged and the fly by wire system had changed to alternate law. Between 02:11Z and 02:13Z a flurry of messages regarding ADIRU and ISIS faults arrived, at 02:13Z PRIM 1 and SEC 1 faults were indicated, at 02:14Z the last message received was an advisory regarding cabin vertical speed. That sequence of messages could not be independently verified.”

Your sequence sounds very plausible; some initiating event (structural failure, fire, bomb, mass electrical problem, whatever) causes the autopilot to disconnect and the flight computers to go haywire, and things spiral (perhaps literally) from there.

}:-)4

[CodeToad]

“The storm was ugly but not that bad.”

Did you check the weather observations on that storm. We did. It was very ugly and the size of Florida.

[CodeToad]

“Being a military pilot for 20 years.”

I don’t know of a single military aircraft rated for thunderstorms. Which ones have you flown through a thunderstorm?

[Jewbacca]

“I don’t know of a single military aircraft rated for thunderstorms.”

Then you haven’t looked

“Which ones have you flown through a thunderstorm?”

A Soufa (and you might want to look up what that name means in Hebrew).