Air France 447 Reported Missing

[carholme]

canwhitewolf;

I do not have an idea of what happened to this flight as there is not enough information, so I will defer to your wisdom and expertise.

You are right that you can post whatever you want.

carholme

[Rockie]

For the record, I haven't expressed any opinion on what I think caused this crash because I simply don't know. I only imparted some technical information regarding the flight control computers, plus emphasized how serious and difficult incorrect or loss of airspeed information can be to deal with especially at high altitude.

This is a very complex airplane. Information from pitot and static pressure sensors is crunched by electronic modules before it even gets to the air data computers, and from there it is sent to all kinds of different computers like flight controls, pressurization, landing gear etc for their own use. System integration on this airplane is comprehensive which means a simple fault in one place can have far reaching consequences somewhere else. Whatever triggered this chain of events has yet to be positively determined, and following the trail of failures that actually led to the crash will be a long process assuming they can even retrieve the DFDR and CVR.

[c170b53]

The reason I posted the data on the probes and PHC is so that you can see albeit there could be a problem with them (more likely if supplied from external power than ship power) there's nothing that jumps out from Airbus and says here I am. Aircraft are constantly being upgraded to correct for known design issues.
For the revised lightning strike theory to the now composite failure theory, (just having fun CWW) the A310 aircraft is typical of early generation aircraft with composite surfaces. In these aircraft, there's no force measurement when actuators move a surface, but rather just displacement measurement. There has been hidden failures in both Airbus and Boeing Rudder systems where unequal actuator forces have caused front spar fractures. With the newer designs the FCC's measure (feedback) actuator output forces to ensure no twisting takes place of spars and if there's a failure, to provide automatic protection by removing the faulty actuator from the system. Having said that in this accident, during the cruise the rudder would have been in a yaw damping mode.
Could the surfaces be ripped off? Sure, no different than my 170's surfaces if I remained in a dive. If a composite primary component had a major flaw in manufacture it too could be at fault. If this was a design flaw then this wouldn't be the first as it has relatively low hours. So it really must be confirmed what occurred first, the primary structure failure followed by uncontrolled flight or uncontrolled flight then structural failure.
I've been on the flight deck (A310) when the crew inadvertently at night (whilst in a hard climb) went from (I believe) Flt LVL change to Alt hold when within 300 ft of that selected altitude. The aircraft reacted like a LA class sub breaching the surface in Red October. All hell broke lose in the cockpit and it lit up with warnings, cautions and a multitude of aural warnings but the crew did the smart thing, they both removed their inputs and let the A/P deal with their mistake.
In this case the A/P disengaged so that put them at a disadvantage as added protection was lost, then a series of events occurred leading to system failures which might have lead them into a mistake.

[canwhitewolf]

.
For the revised lightning strike theory to the now composite failure theory, (just having fun CWW) .

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thats ok having fun

the revised lightning strike theory to the now composite failure theory are in fact not changed or ever were, they can be connected, there is that possibility.

this kinda stuff isnt just my view here, this is stuff thats been looked into very seriously by engineers on composite strengths, what its like at -50 C, what is the effect of a lightning strike, is there any way it could affect the strength of a composite structure and so on, much research to try and make everything as safe as possible, theres on doubt about that.
The Air Force Research Laboratory and Lockheed Martin's Skunk Works have just flown a proof of concept composite plane they put together, far less fasteners far less parts,much research going on

[Widow]

Photo released today.



(See all released by F.A.B. here: http://www.fab.mil.br/portal/voo447/fotos.php)

[Buzz Lightyear]

For those of you who speak French, a very interesting analysis of the events by French pilots, with a link to a internal note from the Flight Ops Dept of Air Caraibes describing the same type of incident on 2 A330, fortunately with a much better result.

http://www.eurocockpit.com/

B.

[Widow]

Pilots Union

Alter, the Paris-based carrier’s third-largest pilots’ union, yesterday urged members to refuse to fly A330s until at least two of the three airspeed sensors on each plane have been upgraded.

In response to a meeting yesterday between pilots and the airline, Air France pledged to ensure that all its flights involving A330s and A340s would be equipped with at least two of the newer speed sensors, effective today, according to a spokesman for the airline’s biggest pilot union, SNPL France ALPA.

“This may lead to some delays, or even cancellations,” said Erick Derivry, a spokesman for that union.

Air France’s Petteau declined to confirm Derivry’s comments about the change in sensors being effective starting today.

(Full article here: http://www.bloomberg.com/apps/news?pid= ... in_america

[xsbank]

How strange to have 3 or more pilot's unions in one company....

[Troubleshot]

Those pictures send shivers up my back.

[canwhitewolf]

dltd

[OntheNumbers]

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just a bit of rough translation,

whats interesting is the first line of the acars data on the above link, ( see attachment below )which states
CTL RUD TRV LIM FAULT .......what does it mean to anyone here? any thoughts

***

Well just a wild guess, but I'd read it to mean "Control RUDDER Travel Limit Fault". When machines with moving parts are designed they will often put something in place to prevent the part from moving itself to destruction. If you think of a power window in a car, for instance, even if you hold the switch forever, the window still stops moving when it reaches the bottom. The circuit usually has a limit switch to kill the motor. It would make sense in an FBW aircraft to have a similar kind of protection in case the control software went nuts and didn't shut off the motors when it was commanded to. If so, then perhaps this warning message is indicating the rudder (RUD?) went past its designed movement limit or something.

Maybe Rockie has a better idea.

[PJ1]

I wouldn't neccesarly call it a RTL fault, but if it is getting bogus air speed information it could have gone in to full deflection mode. At a very high speed. Perhaps a link in a chain of events.

[Fox 3]

The EASA released a Safety Information Bulletin today regarding pitot tubes:

http://ad.easa.europa.eu/ad/2009-17


Thanks for the link to the photos widow.


~FOX~

[MrWings]

Having a defective pitot tube is the best scenario for Airbus at this point.

Having an aircraft that isn't authorized for flight in areas where electrical activity is present is the worst.

[invertedattitude]

I've been following this accident on another forum, but I would also like to add my input here that from the current evidence provided it seems to lean towards an AA587 style event? I'm not saying an identical accident obviously, but something that perhaps overstressed the vertical stab, I suggested this a couple of weeks ago, and this picture only seems to bolster that theory.

[invertedattitude]

I find it interesting that in both these pictures, the rudder seems to be hard-over to the right, in the second picture it appears to be because of the sling used to bring it out of the water, but in the first you can see it was in the same position while just floating there....







The first picture gives a better indication of where it separated, it seems to have perfectly sheared off of the fuselage, for what reason remains to be seen of course.

Picture for reference:

[Rockie]

********************************************************************
just a bit of rough translation,

whats interesting is the first line of the acars data on the above link, ( see attachment below )which states
CTL RUD TRV LIM FAULT .......what does it mean to anyone here? any thoughts

***

Well just a wild guess, but I'd read it to mean "Control RUDDER Travel Limit Fault". When machines with moving parts are designed they will often put something in place to prevent the part from moving itself to destruction. If you think of a power window in a car, for instance, even if you hold the switch forever, the window still stops moving when it reaches the bottom. The circuit usually has a limit switch to kill the motor. It would make sense in an FBW aircraft to have a similar kind of protection in case the control software went nuts and didn't shut off the motors when it was commanded to. If so, then perhaps this warning message is indicating the rudder (RUD?) went past its designed movement limit or something.

Maybe Rockie has a better idea.

As the name implies, the rudder travel limiter limits the deflection angle of the rudder as a function of speed above 150 kts. Maximum deflection is 31.6 degrees at 150 kts decreasing non-linearly to 4 degrees at 350 kts. It is a two channel function, and the fault above indicates failure of both channels. With this failure the system is supposed to freeze the rudder travel at the value permitted at the time of failure, increasing to maximum as soon as slats are extended. The ECAM calls for speed to be limited as well to 160 kts.

This fault cannot be looked at in isolation though because it was one of many failures which seems to have started with loss of airspeed information, but it isn't known yet what sequence of events caused what or whether the systems defaulted the way they were designed to. In other words, piecing together what happened here and in what order will take a long time, and when we're talking about electronic failures like this only the engineers will be able to make sense of it.

[Widow]

Good news for recovery?

Crash Investigation Models Suggest Black Boxes Beneath Debris
By Laurence Frost and Andrea Rothman

June 10 (Bloomberg) -- Computer projections used by the Air France crash investigation show that the flight recorders probably lie beneath the plane’s surface debris or close by, said two people familiar with the inquiry.

Winds in the mid-Atlantic area may have limited the wreckage’s drift after the June 1 crash, countering currents that travel 40 kilometers (25 miles) per day, the people said. They asked not to be named because the inquiry is confidential.

The computer model places the Airbus A330’s likely point of impact in the area where search teams found the first of hundreds of fragments of the plane, the people said. It will help to guide the French nuclear submarine Emeraude, which today joined the search for the cockpit voice and data recorders. There were no survivors among the 228 passengers and crew aboard Flight 447, bound for Paris from Rio de Janeiro.

(Full story here: http://www.bloomberg.com/apps/news?pid= ... 5r3f4cvLuU)

[beaverbob]

A sad side note to the discussion.

A lady and her husband missed their flight that night and took a later flight to France.
Yesterday the lady was killed in a car accident.

Is that not the strangest?

Bob

[mabcan]

Bob, what is your source ? There's nothing in the french medias about this couple since they arrived. In typing her name (Amina Ben Ouargha-Jaffiol) I don't find any trace of this kind of event.

About their arrival in France
http://www.midilibre.com/articles/2009/ ... llier.php5
http://www.rtlinfo.be/rtl/news/article/ ... 2C+en+vain

[Widow]

Wrong couple. Try this - TimesOnline: Woman Who Missed Flt 447 is Killed in Car Crash

[beaverbob]

I heard it on Global news a 6 PM an 1130 news radio this afternoon. The car accident was not in France. Sorry, I can't remember where it happened.

It just seems sad and ironic that she would be a 1/2 hour late for a flight that crashes and then have a fatal car accident 2 weeks later.

Bob

[Inverted2]

I heard it on Global news a 6 PM an 1130 news radio this afternoon. The car accident was not in France. Sorry, I can't remember where it happened.

It just seems sad and ironic that she would be a 1/2 hour late for a flight that crashes and then have a fatal car accident 2 weeks later.

Bob

Holy crap! I guess her time was up!

[Hotel Tango]

sounds like a scenario right out of those Final Destination movies.

[canwhitewolf]

3 more bodies found from lost Air France jetliner


http://www.google.com/hostednews/ap/art ... wD98P55D00