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AF447

Old 10th Jun 2009, 00:54
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Consider the A320 crash near Perpignan. Apparently they failed to recover from slow flight around 3000-3800msl and descended into the sea.
By the way the interim accident report for this flight seems to be very worth reading.

http://www.bea.aero/docspa/2008/d-la...la081127ea.pdf
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Old 10th Jun 2009, 00:55
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mseyfang, the Brazilian map showing where bodies were recovered was generally along a SSW-NNE axis. The current at 4N 30W is from east to west. The prevailing surface winds in that area would also be from east to west.



Chart from Wiki.

Last edited by SaturnV; 10th Jun 2009 at 01:03. Reason: clarification
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Old 10th Jun 2009, 01:02
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This isnt the time for internal squabbling.I dont know about others but I find posts from the self-appointed experts just as annoying as repeated enquiries about the ACARS LAV message.And they want to restrict contributions to this type of thread to pilots only..Last 2 constructive posts came from A330 tech and Fly by wife(#765) so go figure.Its all guesswork,all speculation,we know that.What is the alternative?Enforced silence.Is that better?

Naturally,the picture of an almost pristine and complete VS bobbing in the Atlantic and the report that bodies have been found 85kms apart seems like a smoking gun but I'll go along with ELAC(for now) and accept that they may not have encountered weather,lost airspeed and perhaps attitude reference and got their VS torn clean off in the ensuing upset.I see 411A was shot down in flames but what he said is correct.Use rudder(significant amount) for anything other than x-wind/asymmetric flying in a commercial transport and you do so at your own peril.Not suggesting AF crew did this(just in case ELAC
is still in"police" mode).

The Air Caraibe incident needs to be examined(the value of a precedent in any investigation is immeasurable) and focus maintained on the ACARS messages.
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Old 10th Jun 2009, 01:07
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The AA acident was not the only occasion that a rudder separation was a major factor in an accident. There was another incident when a significant section of either rudder or V/S come off on an A310 somewhere in the Caribbean. What was of interest in the photo of the AF V/S section is that it was not attached to anything else. This leads naturally to speculation (which is what all these posts are) that the V/S may have separated from the rest of the aircraft. Its obvious that there is much more that needs to be looked at but I could well imagine that the investigators will be instigating another line of investigation.
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Old 10th Jun 2009, 01:27
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wes wall;
No doubt there are many who share the same thoughts, but there is nothing which has been discussed that offers any credible evidence to any onset of trouble. What ever happen occured prior to the first ACAR.
Yeah, I don't think we're alone by any stretch - probably most crews here are quietly expressing the same thing when they discuss it, but there's just nothing to peg the "sense of it" on yet.

ttcse;
I also believe it keeps the af447 tail discussion inconclusive.
Yep. It's as inconclusive right now as it was a week ago last Monday. All we have are some disparate facts which cannot be placed in the accident sequence, and a few knowns such as the condition of remains, and of the vertical stab.

I might observe that the "CREW REST" wreckage may likely be from the F/A crew rest module, not the cockpit crew rest area. I say this because the cockpit crew area is not labeled, it generally being near the cockpit. But the F/A module is, in some cases, removable and as such, labeling makes a bit more sense, (when stored...not when 'in use'). The location of this module varies with airline - some are mid-wing, others near the tail section; to the best of my knowledge, all such modules are below the main cabin floor.

Last edited by PJ2; 10th Jun 2009 at 01:38.
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Old 10th Jun 2009, 01:43
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Thanks for the diagram of antenna locations, Saigon Lost. It gives evidence that the vertical fin was intact throughout the period of the ACARS reports, else there would have been HF Fail reports, too. The VOR antennas are not monitored, but the HF antenna couplers, in the leading edge of the vertical fin, are active LRU, Line Replaceable Units, that are powered, and provide fault reporting to the transceivers, which would, in turn, report to the ACMS, and from there to ACARS.

GB
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Old 10th Jun 2009, 01:50
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LH Ops shift change

Respectfully, I submit the following:

I was wondering about specific change points , and inflight shift change. And if there was a crew change once it was at cruise? I recall awhile back mid 1990s, ARSR report referencing some LH transition issues.
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Old 10th Jun 2009, 01:58
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Originally Posted by Finalapproach9L
Respectfully, I submit the following:

I was wondering about specific change points , and inflight shift change. And if there was a crew change once it was at cruise? I recall awhile back mid 1990s, ARSR report referencing some LH transition issues.
How can there be any "issues" with crews taking breaks?

At my airline we have 3 pilots on flights over 9 hours. Typically on a 10 hour flight all 3 pilots are in the flight deck for 30 mins after T/O and 30 mins before landing.

The remaining 9 hours would be split into 3 hour breaks for each pilot. Junior guy usually takes the first break and the flying pilot takes his choice.

Longer flights would sometimes get a long and short break for each pilot.
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Old 10th Jun 2009, 02:21
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How can there be any "issues" with crews taking breaks?
The issues might be somewhere else. No problem with breaks, it only depends WHERE the crew can rest and HOW.

First, if you need to rest right after beginning duty, you'r rather sit, eat, read or watch a movie to relax, because you can't sleep just having barely gotten up. Some airlines just provide a sleeping tube, that's it! You can't eat or sit up for hours!! Rest is reduced to torture and basically not giving what was intended, you'll get red-eyed pilots. Safety compromised.


Second, if the crew rest facility is way back in the aircraft (especially if it is a mobile one), then access confines you to travel through the whole cabin, during service, or worse, during a uncontrolled flight phase and panicking passengers. Why would this be an issue? Simply because in a 3 man cockpit, the captain will also rest, typically in the middle of the flight (!) and would want a rapid access to his seat in case of trouble. Furthermore it has been proven over and over again, that in trouble all hands on deck helped save the flight. 3 men are better than 2 with increased and emergency workload. Placing crew rest away from the cockpit might save money, but you compromise safety again. This is not only a Airbus issue, mind you.

Two questions arise here:
- When was the skipper resting? Was he in the cockpit?
- Where was the crew rest bunker placed? Could the 3rd pilot access the cockpit in due time to help?
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Old 10th Jun 2009, 02:23
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Thanks for the diagram of antenna locations, Saigon Lost. It gives evidence that the vertical fin was intact throughout the period of the ACARS reports, else there would have been HF Fail reports, too. The VOR antennas are not monitored, but the HF antenna couplers, in the leading edge of the vertical fin, are active LRU, Line Replaceable Units, that are powered, and provide fault reporting to the transceivers, which would, in turn, report to the ACMS, and from there to ACARS.
Awesome post. A perfect example of why this board rocks! You just crossed the early breakup hypothesis off the list.
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Old 10th Jun 2009, 02:27
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TCAS Fail

Re-thinking the TCAS Fail report, and inputs that could have caused it:

Airspeed: airspeed has no input to the TCAS, so possible clogged pitot is unrelated.

Altitude input fail: Altitude data goes to the transponder, not the TCAS processor. Transponder would report Altitude Fail, but that is redundant with the ADIRU air data fail message, so may be suppressed. Transponder would revert to Mode A, making the TCAS inoperative, which would trigger a TCAS message. It's hard to tell from the ACARS reports if the Altitude function of the ADIRU was inoperative as well as airspeed.

Attitude Fail: Pitch & Roll are fed to TCAS, so IRU Fail would trigger the message.

Heading Fail: used only for smoothing target movements, so not worthy of a TCAS report.

Radio Altimeter: unlikely that both could fail at this time, although they can lock onto really heavy rain, but not at FL 350.

Antennas: A TCAS antenna fail would trigger TCAS Fail. Hate to say it, but one cause could be lightning.

GB
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Old 10th Jun 2009, 02:31
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Air India 182 was restricted to 35,200 feet and 290 knots as it was ferrying an engine. The bomb detonated while the plane was at 31,000 feet and 296 knots. The plot of the wreckage on the sea floor revealed that it was mostly scattered along a NW-SE axis over a distance of 6.5 NM, or generally between 12.49W and 12.41W. The westernmost definitively identified portion of the wreckage was found at nearly 12.50W. Lighter and smaller pieces constituted most of the wreckage on the easternmost portion of the axis.

Plot can be seen here on the last page of the pdf.

http://www.publicsafety.gc.ca/prg/ns.../CASBai-en.pdf

All the bodies were recovered within five days, which may have been more a function of the plane being tracked by radar, and relative proximity to the Irish coast. The report does not indicate there was significant dispersal of floating wreckage by current or wind. Between 3 and 5 percent of the plane was recovered as floating wreckage.
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Old 10th Jun 2009, 03:19
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I admire the way you deduce and reason, Graybeard . Makes this thread worth following. Thank you.
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Old 10th Jun 2009, 03:32
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POOL..........this is NOT an Airbus or Boeing issue ( crew rest location )

It's the AIRLINE that specify where the rest is located depending on how cheap they are.

The 777 has an overhead crew rest for the cockpit crew above the first class cabin available, BUT some Airlines choose to go with a cheaper option instead. ( down the back cargo hold )

So don't blame Airbus or Boeing.
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Old 10th Jun 2009, 03:50
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In my understanding

tropical storms have a lot of energy esp at lower levels.

Like Tagor sys, Lateral separation is often the best.

While at low altitudes, the speed margin is more, so is the severity of turbulence and icicng esp at SAT above -40 deg C

Further in Europe and in any monsoon type of weather, at lower levels one would definitely be in icicng conditions for a longer period of time .

I suppose it would be a calculated risk at the time to go around a storm (if you can vertically?) vs through it.

Hope this helps...
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Old 10th Jun 2009, 04:06
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Mods please...Some of these first time posters obviously have no knowledge of aviation! I suspect some of them are media.
That is why the forums have a report this post function. Replying to (and quoting!) the offending post is not likely to be spotted by the mods as quickly as reporting a post will be. You click on this - - just over in the left hand area, beneath the poster details, to report a post.
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Old 10th Jun 2009, 04:31
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GE90115BL2 wrote:

It's the AIRLINE that specify where the rest is located depending on how cheap they are.

The 777 has an overhead crew rest for the cockpit crew above the first class cabin available, BUT some Airlines choose to go with a cheaper option instead. ( down the back cargo hold )
So don't blame Airbus or Boeing.
It's precisely for guys that have a problem with AB vs. B that I wrote:

Placing crew rest away from the cockpit might save money, but you compromise safety again. This is not only a Airbus issue, mind you.
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Old 10th Jun 2009, 04:38
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Naturally,the picture of an almost pristine and complete VS bobbing in the Atlantic and the report that bodies have been found 85kms apart seems like a smoking gun but I'll go along with ELAC(for now) and accept that they may not have encountered weather,lost airspeed and perhaps attitude reference and got their VS torn clean off in the ensuing upset.
@Rananim

Now hold on a minute there Sunshine. I stated absolutely nothing of the sort. The only thing I have stated is that there is no evidence available from which the actual track of the flight relative to the weather can be determined. Did they deviate or not, I don't know and neither do you. Did the accident occur from inadvertent penetration of a CB causing an upset? Or, was it the result of circumstances similar to those experienced by the Air Cairibe flights while deviating around convective weather but while still in cloud compounded by an ensuing incorrect pilot response? Or, is it possible that the accident resulted from an extreme turbulence upset while deviating clear of the storms?

Three different possibilities (at a minimum) with different implications regarding potential failures of the aircraft or the crew. None can be proven without the requisite evidence, so what's the point of pre-judging on the basis of the limited bits of information we do know?

ELAC
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Old 10th Jun 2009, 04:44
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Excellent Points by captainflame

Captain Flame posted:

Let's put this one to rest once and for all !

The message F/CTL RUD TRV LIM Fault is justified by the loss of the ADR data.

As said previously in this thread, the rudder travel is then limited to 10 degrees and full deflection is only recovered at slats extension.

An Air Caraibe A330 incident report is circulating (in french) which describes a (survived) event sounding very similar to the AF447 event.

In the air Caraibe event (which I will try to find in english)....icing over of the Ptot probes and TAT probe at FL 350, in transoceanic equatorial WX, with severe turbulence, occured.
The following ECAM messages, flags and system reversions are consistent with the ones reported ont the AF447 ACARS report.

As decribed earlier in this thread, the TAT increase from -14 to -5 degrees typical of an iced up probe measuring the ice temperature instead of the Ram Air.
At some point in this event the CAS, MACH and ALT go respectively from 274Kts, M0.80 and FL350 to 85kts , M0.26 and FL347.

At the same time the cascade of ECAM warnings and cautions include NAV ADR Disagree, F/CTL ALT LAW, F/CTL RUD TRV LIM, ENG EPR mode faults (different engines there), Speed Flags on PFDs, loss of FDs, A/THR, etc....Including at some point STALL STALL audio warning (no protection in ALT LAW)

Summarily, the PF flew "pitch and power" with PNF on QRH unreliable speed indication, disregarding the STALL warning and using backup info of GPS Ground speed and Altitude (ND and FMGC).

Air Caraibe has modified all the 330 probes earlier this year.

Again, the Air caraibe report is VERY similar to what is now known of the AF447 troubles. (Weather, turbulence, airspeed data problems)


Guys I'm on the other side of the world, so while most of you are posting and moving on to other subjects, I'm counting sheep and then still responding to the "resolved" posts the day before! Forgive me if I'm five pages behind.

I hadn't read this A330 report earlier even though I downloaded it. Even though it is in French, It's clear most of the "events" logged about the accident/incident are almost identical. As the good "Captain Flame" stresses the engine EPR differences are moot, they are just airline customer engine selection options: For example on the previous gen aircraft the A310, you could order with Pratts w/EPR or GE's w/out EPR. In the latter case, since all you have is N1 for thrust settings you wouldn't get EPR (engine pressure ratio) errors logged (since you don't have those gages), you wouldn't see those EPR faults or warnings into the mtc computers. The aircraft system then reports these conditions to ACARs, and ACARs would then bundle this information into a data packets and beam it to the satellite or HF if, that service was paid for.

To oversimplify for non aviation types: ACARS is a telephone. If the Cable Guy (Installer) has problems with your TV/black box, he's going to ask you to use your telephone (ACARS) to report the faults to somebody back at his company (AOC/Maintenance Control) who is smarter than he is. Previous posters asked where the location coordinates for the last 0214z acars report came from since it didn't show up in the acars report. This is a good question. It appears the images on the first few pages of this thread from Channel2 France, are of a finished "environmental" report constructed for AF maintenance. We are not seeing the actual data packets (which would have sat broadcast coordinates,) which are broadcast line-of-sight to the satellite in a different computer language.

Here are excerpts from Wiki on ACARS:

SATCOM and HF subnetworks
SATCOM provides worldwide coverage, with the exception of operation at the high latitudes (such as needed for flights over the poles). HF datalink is a relatively new network whose installation began in 1995 and was completed in 2001. HF datalink is responsible for new polar routes. Aircraft with HF datalink can fly polar routes and maintain communication with ground based systems (ATC centers and airline operation centers). ARINC is the only service provider for HF datalink.
[edit]Datalink message types
ACARS messages may be of three types:

Air Traffic Control (ATC)
Aeronautical Operational Control (AOC)
Airline Administrative Control (AAC)

ATC messages are used to communicate between the aircraft and Air traffic control. These messages are defined in ARINC Standard 623. ATC messages are used by aircraft crew to request clearances, and by ground controllers to provide those clearances.
AOC and AAC messages are used to communicate between the aircraft and its base. These messages are either standardized according ARINC Standard 633 or defined by the users, but must then meet at least the guidelines of ARINC Standard 618. Various types of messages are possible, and these include fuel consumption, engine performance data, aircraft position, as well as free text data.....

(Each airline must tell its service provider(s) what messages and message labels their ACARS systems will send, and for each message, where they want the service provider to route the message. The service provider then updates their routing tables from this information.) Each type of message sent by the CMU [Communications Management Unit - CC] has a specific message label, which is contained in the header information of the message. Using the label contained in the message, the DSP looks up the message and forwards to the airline’s computer system. The message is then processed by the airline’s computer system.
This processing performed by an airline may include reformatting the message, populating databases for later analysis, as well as forwarding the message to other departments, such as flight operations, maintenance, engineering, finance or other organizations within an airline. In the example of a delay message, the message may be routed via the airline’s network to both their operations department as well as to a facility at the aircraft’s destination notifying them of a potential late arrival.
Those who claim that the ACARs data doesn't mean anything, are incorrect.
These messages are the best information we have thus far and they appear nearly identical to other A330 known mishaps. If history is any guide, since billions are on the line in Aircraft Ops and Sales, it may be years before the findings of this investigation are made public.

All my posts are just my opinion only.


CC
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Old 10th Jun 2009, 04:52
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Originally Posted by 727gm
Not saying ACARS messages are related to loss of VS.
............................................Doesn't help thread to try to put words in other poster's mouths.
Actually your post appeared to have alluded to this indirectly. I responded, but relented and was deleted.

No harm done I hope. It was getting tiring hearing about vertical stabilizers and the loss of AF447. The two are unrelated at this point as a causal factor according to the information, scant as it is, provided so far.

Even the Seattle Post had an 'engineer' claim the Rudder TRVL Limit message was not a reported fault of the limiter, most likely due to the loss of ADIRU data, but an actual rudder over-excursion.

I had previously posted a correct interpretation by a retired but qualified A330 engineer to the contrary and explained it in this post of mine earlier.

Sorry if I was a bit too harsh 727gm.
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