AF447 [Archive] - Page 8

stickyb

17th Jun 2009, 01:25

I have gone back again to look at the ACARS messages. I posted in #843 on 9th June that at least some of the messages had been truncated, but not many people seem to have picked up on that fact.

Now, looking at the format of the printout, what else can be discerned?

1. the listing seems to be a subset of messages extracted from the total acars info available for AF. The selection criteria appear to be a) by reg no. FGZCP and b) by time - 120509 thru 010609

So someone has run a programme that does "show me a list of all acars messages received from FGZCP between 150509 and 010609

There could well be other filtering applied, as I am led to understand that other things are reported on acars on the normal takeoff/landing event.

2. The list appears to be displayed in earliest flight first order, and latest message first within flight. This seems slightly confusing, as you have to then read down the printout from page 1 for a chronological sequence of flights, buit then having found the flight you are interested in go to the bottom of the list for that flight and read backwards to get a chronological sequence of messages.

3. The timestamp displayed as part of the messages is not the timestamp used for sorting the messages into the displayed order, as some messages "appear" to be out of sequence. Maybe there is a separate undisplayed timestamp such as arrival time, and maybe the messages are not even transmitted in chronological sequence - some messages could be deemed more important than others and therefore jump the transmission queue.

4. The appears to be a "trailer" message at the end of a flight. This is the message with just / from what i assume is the previous flight, along with the PFR message from 2013. Maybe someone can decode that?

Therefore my assumption is that the first 27 pages contain messages from previous flights of that airframe. What puzzles me is that the list seems to go on for 256 pages, implying that there are many more messages following on from the ones we have seen. It is certianly an odd coincidence that the list would end exactly on a page boundary. I would also add that 256 is one of those "magic" numbers in computers, and could just indicate that a lazy programmer couldn't get the code right to count the number of pages that were going to be printed.

All this simply leads me to caution on attributing too much authenticity to these messages

ELAC

17th Jun 2009, 01:30

ACARS information.

It seems convenient that we see two ACARS messages concerning AF 444 on the 31st of May, preceding any messages relating to AF 447 -

However we see no messages relating to any other flight, post- the supposed 'last message' from AF 447 at 02:14z.

This leads me to question whether or not there were any further messages from 447.

Surely it would put it to rest, if we for instance had seen the string of messages from AF447 cease, and the next batch from another flight begin (as was seen with the messages from AF 444 leading into the AF 447 messages).

To whatever degree these messages have been truncated, I can't be sure we're getting the complete story from beginning to end.

These are pages 28, 29 isolated from list of messages 256 pages long.

What is shown on page 27?

JLL.

JLL,

I think you're wandering over into conspiracy theory territory here. First off, to my knowledge the ACARS message report that we've seen is not a document released by an official source within Air France or BEA but rather was printed off by someone with access to the AIRMAN system who then made it available to the media. It is that individual who will have chosen what they considered relevant and what not, not any part of the officially involved parties.

Second, if you review the page headers you'll notice that they they include a block that reads "Materiel: AV FGZCP REG". I'm no expert on the system but a reasonable guess is that the output listed below is a result of a search for messages transmitted by FGZCP and hence messages from other aircraft would not be shown. If they were you might see some interspersed between FGZCP's 26 messages. Obviously there would also be no messages to show subsequent to the last one received. As the last message on the sheet coincides with a page end we can't be sure that we are seeing all that there is, but particularly given the unofficial nature of the source can you think of any reason why they might have withheld anything they considered relevant?

Jetdoc

17th Jun 2009, 02:19

http://i658.photobucket.com/albums/uu308/Jetdoc1/341115.jpg

This is getting pretty funny. I dont recall seeing a fault message 34-11-15 but several pages back, someone posted a listed of components and their related AMM references and said that they were fault messages. I've reproduced the first page of eight pages of the AMM reference 34-11-15. As you can see, this tells you how to replace the Pitot probe.
These fault messages are for use by maintenance personnel as a starting point for troubleshooting. Different fault codes give different clues and different starting points in the troubleshooting process. Nobody stands around trying to interpert them.
I would hope that nobody thinks that this aircraft seriously produced 256 pages of faults. The airplane would have to have been falling apart one component at a time. There were probably endless streams of messages to the maintenance control department from all over the world that night and these messages wound up on these pages.

augustusjeremy

17th Jun 2009, 03:15

JetDoc,

In post 41 you will see the list of the 24 ACARS messages

In the third from bottom to top you will find the wording "34111506", among other things, which, as already discussed here, relates to the ATA code 34-11-15 which directs to the pitot tube (-s ?). The 06 relates to the flight phase (cruise)

I don't know if "Troubleshooting Manual" equals "Maintenance Manual". So in the "Troubleshooting Manual" - if it differs from the "maintenance manual" - maybe there is some other reference linked to the pitot tube(s) - in other words, linked to the same code 34-11-15.

pattern_is_full

17th Jun 2009, 03:21

I hope this will be taken as intended - as an anti-speculation post.

1. Is it really safe to assume that all three pitot tubes were giving false readings? All three might disagree - but that would also be true, would it not, if only two were giving false readings and the third was still functioning normally in all respects? In the event it probably does not matter, since the computers are going to report a three-way disagreement and toss it to the pilots in either case...I just caution against stating flatly that all three pitots failed. We don't know that.

2. The cabin altitude warning seems equivocal. Plane decompresses - or - plane rises 2,000 ft. in 20 secs. in a convective updraft - or - plane drops 2,000 ft. in 10 secs. in a convective downdraft - or - plane ascends/descends rapidly for some other reason. Would not any rapid altitude change in either direction that exceeded the pressurization/venting system's ability to keep up lead to this warning?

augustusjeremy

17th Jun 2009, 03:28

1. Is it really safe to assume that all three pitot tubes were giving false readings? All three might disagree - but that would also be true, would it not, if only two were giving false readings and the third was still functioning normally in all respects? In the event it probably does not matter, since the computers are going to report a three-way disagreement and toss it to the pilots in either case...I just caution against stating flatly that all three pitots failed. We don't know that.

We could ask a simpler question: Does the code 34111506 in the ACARS message set mean that there wasn't a valid airspeed reading/value availabe ?

TerraHertz

17th Jun 2009, 03:34

Publicly known ACARS messages originate from a June 4th (evening?) "French television station France2 produced the ACARS messages from the last minutes of the flight of the A330. The data was clear on screen and has since been reproduced here."

Flight 447 was lost on June 1st. So we have:
* 3 to 4 days interval between loss of Flt 447, and appearance of the public ACARS data.
* The data 'release' involved both error-prone visual/manual transcription from a screen capture, and a mainstream media source.
* At least one potential factual error has been identified in the data.
* The 'known' ACARS data is very likely incomplete - it omits non-maintenance streams, and possible records prior and subsequent to the available ones.
* There is no formal provenance to even the 'known' ACARS messages. I do not have a transcript of the TV station broadcast, so don't know the actual wording used. I must consider that there might have been commentary to the effect of 'typical', 'representative', etc in conjunction to the on-screen text. In any case, TV stations are under no legal obligation to be truthful, and we know nothing of their source.

One thing I find a little odd. All the copies of the 'ACARS text' I can find are images, as opposed to plain text files. Also, someone has gone to the trouble of creating those images complete with faint alternate line shading, as if they are direct scans of line printer output on typical fan-fold tractor feed paper. Yet these are supposedly manual transcriptions, from the screen of a TV news item?

I found two sources of this image:
http://img197.imageshack.us/img197/3410/acarsaf447e.png
http://www.eurocockpit.com/images/acars447.png
They are substantially the same image, but they are not identical. Examining the images closely in photoshop, via a red/blue overlay (see http://everist.org/flt_447/a-b_compare_flat.png) determines:
* They are exactly the same x-y size.
* They are identical in almost all pixels, except for three points of difference, where characters have been altered, added, or moved. (See yellow shaded items in my image.)
* Both versions very likely created by the same source, due to exact pixel correspondence of the non-aliased font used. One presumes that one or other version is an update, with corrections as errors from the visual transcription are noticed.
* They are most definitely electronic image constructions, rather than processed scans of paper documents. There are zero image/colour defects of the type resulting from scans, also the shifting of the "CTL SEC 1 FAULT" item could not result from a scan error.
* Both are identical in the "NAV TCAS FAULT" and the associated '3443' JASC code, which is suggested should read '3445'. (Shaded blue in my image.) We do not know if this is a transcription error, or if the original code really is '3443'.

From the above, one can conclude that the known images really are the product of a manual transcription from a TV frame-grab, as opposed to actual printout scans, merely *said* to be transcriptions to protect someone from charges of leaking confidential documents. Thus the TV station broadcast was the original source.

Now, I'm not suggesting that the known ACARS messages are a fabrication. However one must logically bear in mind that lacking a formal release origin, they easily _could_ be a fabrication.

Worth remembering, given the comments from several official sources that the flight recorders are unlikely to ever be found.

---Some previous relevent posts---
http://www.pprune.org/rumours-news/376433-af447-87.html#post5001546
Being curious about the source of the two pages of ACARS messages, which are labelled 28/256 and 29/256, I looked around to see where they originated. Amazingly, this seems to be it:
http://www.flightglobal.com/blogs/unusual-attitude/2009/06/af447-accident---icing-pitot-t.html
So the crucial text on which everyone is basing analysis, was hand copied from a screen visible during a TV interview! Furthermore I gather from other comments here, that this is just one ACARS stream (maintenance messages?) of several. Also that it isn't publicly known for certain that these two pages are even all the relevent messages from that stream.

http://www.pprune.org/rumours-news/376433-af447-89.html#post5002147
"I'm new to this forum, so hello to all gentlemen.
Some tiny details in the ACARS message list presented by Air France suggest that at least part of it may have been manually edited, a process prone to human error. Looking closely at it, I found a discrepancy between the warning labelled "NAV TCAS FAULT" and the associated JASC code. This code, 3443, stands for NAV/DOPPLER SYSTEM in the JASC classification. However, the a/c was not Doppler equipped. TCAS should be coded 3445.
All other codes appear correctly related to their labels.
Whatever explains this discrepancy, including a possible use of a slightly different classification by Airbus, I believe it should be considered doubtful that a TCAS FAULT warning ever happened."

http://www.pprune.org/rumours-news/376433-af447-89.html#post5002195
"There have been contradictory, vague and confusing descriptions of this 0214z warning and it would be helpful if one of the experts would clarify exactly what it means."

http://www.pprune.org/rumours-news/376433-af447-89.html#post5002268
"What is shown on page 27?"

Sleeping Freight Dog

17th Jun 2009, 03:42

ZFT

17th Jun 2009, 04:18

1)Without knowing what triggered the ACARS messages, how could you feed this into a simulator? (Assuming simulators have a total ACARS simulation which they do not).

2)How could you ‘factor in’ the weather and turbulence when these are still unknown?

jrv

17th Jun 2009, 04:21

Dutch Bru wrote:

Anyone for comments on the possibility that post 02.14ZT ACARS mesages got lost because of range issues concerning INMARSAT (non) coverage of that specific part of the Atlantic (covered in previous post) ???
A (deleted) post states that the messages are transmitted with ECC codes. The use of forward-error correction in a two-way radio scheme strongly suggests to me that the engineers were concerned enough to have implemented an ACK/NACK request-retry scheme so that a message garbled by, for example, a nearby thunderstorm. would a re-transmitted.

The accident investigators will look into this carefully.

augustusjeremy

17th Jun 2009, 04:39

Probably means nothing but let's feed the speculation a bit more:

from post 1190:

At FL 370 with a SAT to -51 ° C and a wind from 080 to about 18 Kts on AWY UB612 with OFF SET 1R, between the OBD and MLK in radio contact with Khartoum, as we were at the edge of layer cloudy with some light turbulence, I tied PAX.

We were at dusk with low brightness.
Then we entered the layer, and soon after we started having a slight BURNING SMELL that lasted about twenty seconds and that did not appear to be of volcanic origin (no smell of rotten eggs), but rather electrical smell to me and smell the air conditioning for the OPL. Then the smell has disappeared. The odor was confirmed by the PAX booth and PNC between rows 3 and 14 thereafter.

from a poster at the (already famous) Tim Vasquez website:

I am an Airbus A330/A340 Senior Training Captain (IRE/TRE) with Cathay Pacific in Hong Kong. As I'm sure you can imagine we experience our fair share of CB activity; and between June and October - Typhoons. We regularly get small ice deposits on the windscreen wipers and ice detector as cold as -54C. Very small amounts, but ice none the less. It only occurs in the upper levels of the anvil of active Cbs and enough to justify the use on engine anti-ice.

On 28th Sept 2004 ( I was a a brand new Captain) there was well defined typhoon ( I can't remember the name) centred on airway A1 between Taiwan and Kagoshima in southern Japan. The SAT at FL390 was around -56C. Heading South, it looked like we could make it over the top of the storm. As we reached the southern rim of the eye the temperature rose instantly to -39C and we entered a violent Cb. The ice build up was dramatic to say the least. Most of the lower half of the windscreen became encrusted and we encountered an electrical BURNING SMELL (which is not uncommon in the A330 in upper cloud).

Once we exited the cloud, the ice disappeared pretty quickly. There was no noticeable effect on the instruments

mm43

17th Jun 2009, 04:57

@TerraHertz

The source of your data was posted originally in this thread -
http://www.pprune.org/rumours-news/376433-af447-3.html

The original poster clearly identifies that it is not an original document, and that he has also modified a part of it.

mm43

Fargoo

17th Jun 2009, 05:14

I'm new to this forum, so hello to all gentlemen.
Some tiny details in the ACARS message list presented by Air France suggest that at least part of it may have been manually edited, a process prone to human error. Looking closely at it, I found a discrepancy between the warning labelled "NAV TCAS FAULT" and the associated JASC code. This code, 3443, stands for NAV/DOPPLER SYSTEM in the JASC classification. However, the a/c was not Doppler equipped. TCAS should be coded 3445.
All other codes appear correctly related to their labels.
Whatever explains this discrepancy, including a possible use of a slightly different classification by Airbus, I believe it should be considered doubtful that a TCAS FAULT warning ever happened.

Just to clarify, in the Airbus manual Chapter 34-43 is indeed TCAS.
Not heard of the phrase JASC before but there is little evidence that the ACARS messages have been manually edited.

Pontius Navigator

17th Jun 2009, 05:33

What is the exact age and flight hours of the accident aircraft.

Is there any information yet that the composite structure, particularly around hinge points etc., may have failed initiating an inflight breakup sequence.

I wonder if this may be a wake up call for aspects of composite airframe design, particularly at attach points.:confused:

Read the thread.

New aircraft 4 yrs, 18000 hrs, IIRC.

selfin

17th Jun 2009, 05:40

Publicly known ACARS messages originate from a June 4th (evening?) "French television station France2 produced the ACARS messages from the last minutes of the flight of the A330. The data was clear on screen and has since been reproduced here."

[...]

One thing I find a little odd. All the copies of the 'ACARS text' I can find are images, as opposed to plain text files. Also, someone has gone to the trouble of creating those images complete with faint alternate line shading, as if they are direct scans of line printer output on typical fan-fold tractor feed paper. Yet these are supposedly manual transcriptions, from the screen of a TV news item?

Guilty as charged :ugh:. Refer to the first three pages of this thread. User Lemurian provided directions to the summary ACARS list on June 5th at 00:00 BST - the list appeared during the 20H France2 television programme on June 4th. At 00:20 BST Danny posted screenshots of the video. At 00:35 Re-Heat posted one enlarged screenshot. At 01:01 and 01:21 users Lemurian and vapilot2004 respectively posted an abridged summary of the screenshots. At 01:26 Machaca provided enlarged screenshots.

At 04:09 I posted a reproduction of the list. The reproduction was intended to be posted in raw text form however the formatting of text on this forum does not allow multiple spaces. On previewing the posting the presentation became stylistically distorted. The text was therefore placed into Pastebin (http://pastebin.com/) and a screenshot was taken. This accounts for the alternate line shading. At about 16:00 - 17:00 I was sent a private message by two contributors drawing my attention to a single-digit typographical error in the ISIS report ATA section code. A corrected version was provided in lieu. Unfortunately numerous online fora took a copy of the erroneous version. I have privately contacted over a dozen distributors (including the NY Times) to bring their attention to the matter. Eurocockpit, IAG, Seattle PI, NYT and others have either already replaced the old version or are working on it.

Original video

The directions originally provided by Lemurian need to be updated (the archive provided in his aforementioned post only shows the past week's worth of 20H broadcasts.)

1. Go to L'info en vidéo - France Télévisions (http://info.francetelevisions.fr/?id-categorie=JOURNAUX)
2. From the left margin select the category JOURNAUX
3. Select subcategory Editions nationales
4. Select programme 20H
5. Select from the central window (which will be populated by daily editions of 20H broadcasts) the broadcast of June 4th.

The summary ACARS list is covered between (approximately) 4 minutes 30 seconds and 8 minutes in (continue watching the broadcast until the end of the 8 minute point.)

The posting on the third page of this forum will now be edited again to reinforce the fact that this is not an official list.

takata

17th Jun 2009, 06:00

Hello,
Maybe this will clarify few details about ACARS and Pitots troubles:
_____________________

FROM : AIRBUS CUSTOMER SERVICES TOULOUSE
TO : ALL A330/A340/A340-500/A340-600 AIRBUS RESIDENT CUSTOMER SUPPORT MANAGERS
OPERATORS INFORMATION TELEX - OPERATORS INFORMATION TELEX
TO: A330/A340/A340-500/A340-600 Operators
SUBJECT: ATA 34 - REQUEST FOR INFORMATION CONCERNING IN-FLIGHT UNRELIABLE AIRSPEED
OUR REF: SE 999.0049/09/VHR dated 09 JUN 2009

CLASSIFICATION: GENERAL INFORMATION

1/ CONTEXT
As reported in AIT reference "AF447 Issue 3 June 8th 2009", there are 3 standards of pitot probes in service on the A330/A340 family aircraft:

- Thales (ex Sextant) PN C16195AA and PN C16195BA
- Goodrich (Rosemount) PN 0851HL

It is reminded that the 'BA' standard probe was made available to address low altitude water ingress events that generated a number of RTO on the A320 family program.

AF447 aircraft was equipped with Pitot PN C16195AA.

The intense speculation regarding these pitot probes has led many Operators to contact Thales or Airbus to:

- request an immediate replacement of the Thales 'AA' probes with 'BA' (Service Bulletins A330-34-3206, A340-34-4200, A340-34-5068)

- report recent and past (previously unreported) events of Unreliable airspeed.

These events, after analysis and confirmation, will allow to determine if any corrective action is warranted by the findings.

In this context, all Operators, equipped with Goodrich (Rosemount) or Thales (Sextant) pitot probes, are requested to report all confirmed in-flight Unreliable airspeed events.

2/ TYPICAL SIGNATURE OF UNRELIABLE AIRSPEED

To be sure that Unreliable airspeed events are correctly identified, please report events corresponding to the criteria as follows:

- Crew report indicates loss or discrepant IAS (Indicated Airspeed) on CAPT and/or F/O PFD and/or Standby Airspeed indicator (ISIS).

- Typical ECAM Warnings were seen:

NAV ADR DISAGREE
NAV IAS DISCREPANCY
F/CTL ALTN LAW
F/CTL RUD TRV LIM 1(2) FAULT
AUTO FLT AP OFF
AUTO FLT A/THR OFF
STALL WARNING (audio call-out)
AUTO FLT REAC W/S DET FAULT

- Fault Message "PROBE-PITOT 1+2/2+3/1+3" was possibly also seen.
- Maintenance report indicates that event was NOT due to a system failure.

3/ AIRBUS REQUEST

Please send all reports corresponding to the above typical signature via email to "[email protected]". Please be sure to include the following points:

- Aircraft MSN affected
- Pitot part number fitted at the time of the event
- Date of event
- Aircraft location at the time of the event.
- Flight phase at the time of the event.
- Altitude at the time of the event
- Weather conditions at the time of the event.
- Indicate what effects on IAS were seen on CAPT and F/O PFD and Standby Airspeed indicator (ISIS).
- Other associated cockpit effects were seen (ECAM warnings etc.)

Volume

17th Jun 2009, 06:04

Is there any information yet that the composite structure, particularly around hinge points etc., may have failed initiating an inflight breakup sequence.Only information available yet is that a major structural element made from composite (the vertical stabilizer) broke of the aircraft and is basically intact, indicating that it broke of quite early in the breakup sequence, most probably already far before the final impact. The point of fracture lies within the metal structure this composite part is attached to. See This picture (http://www.fab.mil.br/portal/voo447/FOTOS/loc_fotos/foto_1.jpg) for example, the two aft metal lug fittings are still attached to the fin with some remainder of the according metallic fuselage frames still attached.
So sorry metal lovers, this time it does not look like a composite issue.

Pontius Navigator

17th Jun 2009, 06:20

Only information available yet is that a major structural element made from composite (the vertical stabilizer) broke of the aircraft and is basically intact, indicating that it broke of quite early in the breakup sequence, most probably already far before the final impact. The point of fracture lies within the metal structure this composite part is attached to. See This picture (http://www.fab.mil.br/portal/voo447/FOTOS/loc_fotos/foto_1.jpg) for example, the two aft metal lug fittings are still attached to the fin with some remainder of the according metallic fuselage frames still attached.
So sorry metal lovers, this time it does not look like a composite issue.

indicating that it broke of quite early in the breakup sequence, most probably already far before the final impact

Any evidence to adduce probable from possible?

Dysag

17th Jun 2009, 06:54

You said "I know of no cockpit crew rest installations which are not near the cockpit. I have seen one option when in the cutting-metal stage for cockpit crew rest facilities below the tail where the F/A's facility was also located and it was rejected out of hand by the pilots association, for what ought to be, (but I take nothing for granted on this thread), obvious reasons."

Probably not relevant to AF447, but the normal cockpit crew rest offering on the A340-500/600 is in the bulk hold. I believe there are several in service with it.

Graybeard

17th Jun 2009, 06:55

There was a lot written about WXR in the first thread, and most of it got deleted before the ink was dry.

There is a little in Tech.

GB

TerraHertz

17th Jun 2009, 07:31

Thank you Selfin for the very detailed history of how the distributed ACARS messages came to be, and their format. It's great to have all that recorded in one place.

However my intent wasn't to attack whoever had transcribed them from the TV images, just to establish that they were, and what their arrival from that source implies. Your explanation doesn't alter the point I was working up to, which is that the original source is a mainstream TV broadcast. And hence that there is still no official release of this data, with any kind of legal responsibility to be accurate and complete.

So one must bear in mind there's at least a potential that what we have could be a fabrication.

d747

17th Jun 2009, 07:37

Hi,
My second post on here so please be gentle....

Regarding the CVR and FDR pingers, Is it possible that the frequency may have changed they are transmitting on?
I was watching one of the discovery channels Air crash programmes regarding an incident with I think an Air India 747 and when they found the tones transmitted they were at a much higher frequency (becasue if water ingress I guess into the electronics) I do understand thease programmes are not exactly accurate!

I havn't read the full 90 pages becasue time only allows me to look here evey now and again so appoligies if this has beed discussed

Kind regards

Dave

Wader2

17th Jun 2009, 08:22

Regarding the CVR and FDR pingers, Is it possible that the frequency may have changed they are transmitting on?

Conceivable but irrelevant.

A radio transmitter typically transmits on one frequency that will only be picked up by a receiver tuned to receive signals on that frequency.

A sonar receiver is a broadband receiver, like a radio hams airband broadband receiver. It will be detecting soundwaves across the entire frequency spectrum.

The beacon transmission frequency was posted earlier. There is one problem with underwater sound and that is ray path propagation. My memories of oceanography are fading except to say that the soundwaves do not travel in straight lines. They will curve and slow as they approach the surface. They will be reflected from the thermocline at about 300-450 feet depending on surface temperature anr previous weather conditions. They will descend before curving back toward the surface. These give rise to convergence zone detection many miles from the source and no immediate clue as to distance if they are detected in the 2nd or 3rd convergence zone, typically a band 4 miles or so wide 30 odd miles apart.

Once near the source then direct path will lead to ultimate location.

The propagation distance deoends, amonst the other criteria, on the emitter frequency with lower frequencies propagating further.

I have copied a piece from #770 from the earlier thread:

[quote]At the frequency of the DFDR/CVR pinger (37.5khz) the average absorption rate in sea water is between 6-10 dB/km. This does not take into account thermal layers. The relationship between absorption and frequency is more on a log scale rather than linear. Lower frequencies can travel further than higher ones, not unlike the audio range in air./[quote]

Combined this suggests that a short range, direct path detection is more likely that a long range convergence zone detection. It returns the issue to a needle in a haystack situation.

minstermineman

17th Jun 2009, 08:45

In the French press conference shown on tv today great emphasis was placed on how reporters / media are coming up with wild theories about probable causes and scenarios for this incident, and that the official investigation was the only reliable way for the information to be forthcoming.

Wonder where a lot of this speculation came from . . . .

HarryMann

17th Jun 2009, 10:23

French: No conclusions yet in Flight 447 probe

French: No conclusions yet in Flight 447 probe - News (http://www.aol.com.au/news/story/French-No-conclusions-yet-in-Flight-447-probe/2095091/index.html)

John47

17th Jun 2009, 11:20

JASC Code Joint Aircraft System/Component
The JASC Code Table is a modified version of the Air Transport Association (ATA) Spec 100 Code. It was developed in 1991 by AFS-600 for technical classification of SDR’s.
The JASC Code Table contains abbreviated titles that clarify the intended use of the code.
ATA Spec 100 Codes contain three (3) digits -- JASC Codes use a four (4) digit format.
For Example: In ATA chapter 24, Electrical Power, the JASC Code for Electrical Power System Wiring is 2497. In chapter 29 Hydraulics, the JASC Code for Hydraulic Power System Wiring is 2997.

The JASC Code Table and Definitions can be found on FAA website FAA: Home (http://www.faa.gov/)

gillesf

17th Jun 2009, 12:20

In French, at Le Point : actualité internationale, économie, actualité Française (http://www.lepoint.fr) (my quick but accurate translation below the french text):

À l'occasion du troisième point effectué par le Bureau enquête et analyses pour la sécurité de l'aviation civile (BEA), Paul-Louis Arslanian, patron de l'organisme chargé de l'enquête technique sur la disparition du vol Rio-Paris au-dessus de l'Atlantique avec 228 personnes à bord (http://www.lepoint.com/actualites-societe/2009-06-01/au-large-du-bresil-un-a330-d-air-france-disparait/920/0/348390) , n'a pas caché qu'il ne disposait pas des rapports d'autopsies des victimes. Celles-ci ont été menées à Recife par les autorités brésiliennes en présence d'officiers de police judiciaire français. Mais le médecin enquêteur du BEA n'a pas été autorisé à y assister. Ce spécialiste est pourtant mondialement reconnu et avait notamment été associé aux autopsies à New York lors du crash du TWA 800, accident survenu en juillet 1996 au large des côtes américaines.

During the 3rd briefing by the BEA, Paul-Louis Arlanian, head of the investigation on the AF447 disappearance, has indicated that he did not have access to the autopsy reports of the victims. These autopsies were conducted in Recife by the Brazilian authorities, in the presence of French police officers. But the BEA investigating doctor has not been authorized to be present. This specialist had been associated to the autopsies in NY of flight TWA800 in July 1996.

RWA

17th Jun 2009, 12:33

Thanks, HarryMann, for the link on the press conference.

Not unexpected I suppose......

But one thing appears very odd. A bit more info. in this similar story:-

"He said a French pathologist sent to Brazil had not been authorised to take part in the autopsies of recovered bodies, and France had not had access to the Brazilian autopsy results.

"During his televised news conference he declined to say more on the subject, but afterwards he was pressed by reporters to say if he was dissatisfied with the lack of access given to the French doctor.

"I am not happy. Eventually, I hope I'll have an explanation. For the time being it is a fact and nothing more. Please don't try to create problems between France and Brazil," he said."

No French access to Brazil plane crash autopsies - swissinfo (http://www.swissinfo.ch/eng/news/international/No_French_access_to_Brazil_plane_crash_autopsies.html?siteSe ct=143&sid=10838622&cKey=1245236902000&ty=t)

Why on earth aren't the autopsy results being passed on to the investigators? Apart from anything else, they'll be absolutely crucial in deciding whether the victims died in the air or in the sea?

PJ2

17th Jun 2009, 12:53

Dysag;
Probably not relevant to AF447, but the normal cockpit crew rest offering on the A340-500/600 is in the bulk hold. I believe there are several in service with it.Thanks; that coincides with the arrangement we saw when asked to examine alternatives for the -500. Perhaps this is the normal offering from Airbus, from which changes may be made. We thought that for cockpit crew, being at the tail of the aircraft wasn't the best idea. That said, the other option behind the cockpit is prone to noise from the galley. I think the 777 has the best arrangement I've seen. The worst was the A330 which was in the J-cabin with a velcroed tent.

Gringobr

17th Jun 2009, 12:57

For those of us who know ( and love ) Brazil,it is probably just bureaucracy, I am sure the French will be given all the results,...

HarryMann

17th Jun 2009, 13:06

Indeed, it would be nice to think there were no obstacles in the modern world to fully co-operating in such matters and neither political, legal, fiscal or national interests prevents a full and fair sharing of information, responsibilites as well as resources...

Professorrah

17th Jun 2009, 13:33

Not wishing to promote any particular newspaper, but this artical seem as good as any and in English

Air France crash investigators: relatives must be patient - Telegraph (http://www.telegraph.co.uk/news/worldnews/europe/france/5558302/Air-France-crash-investigators-relatives-must-be-patient.html)

YRP

17th Jun 2009, 14:52

Originally posted by BOAC:
3) There have been several (I think unanswered) requests here for positions of the groups of bodies found. Do we have any, and has anyone back-plotted the position of the second recovery vis a vis ocean currents to see where they would have been in relation to the first, and likewise for the first to the POSSIBLE crash site?

Even if this information were available, I think it would be difficult to analyze properly. Most people here are not experts on ocean currents. An earlier post mentioned diverging surface currents in the area, and that the sub-surface currents might differ from the surface. So for bodies, which sink and then (I'm assuming here) surface at varying times, backtracking currents to the crash site sounds at least tricky if not completely unreliable.

The same might apply to wreckage. It may be that as the plane (whether it impacted intact or in pieces) sank, pieces of wreckage broke off or worked loose underwater at various times and floated to the surface at different speeds depending on the boyancy of each piece. So backtracing might not be a simple as (speed of current) * (time since accident).

I'm not saying these analyses can't be done. They will be done and by the trained experts. But I will go out on a limb here and say that most posters here do NOT have the background required. For example without years of mechanical/structures/metallurgical engineering education or experience, someone just is not qualified to say whether impact forces could have broken off the VS from an intact airplane or whether it must have separated in midair.

There are frequent pprune posts arguing that non-pilots should not critique pilot actions, and I support that fully. But let's apply the same standard to accident investigation.

NotPilotAtALL

17th Jun 2009, 15:48

Hello,

Air France crash investigators: relatives must be patient

Air France crash investigators: relatives must be patient - Telegraph (http://www.telegraph.co.uk/news/worldnews/europe/france/5558302/Air-France-crash-investigators-relatives-must-be-patient.html)

Seem's it' a constant request by the BEA ....

Relatives of the Charm el-Cheikh, crash Flash Airlines FSH 604 are a perfect exemple of patience ....

augustusjeremy

17th Jun 2009, 15:52

- doesn't really answer aj's question about the Inertial Systems? Are there any required parameters other than profile rate?(First I would like to thank PJ2 for pointing to the diagram at post 1034.Thanks BOAC for your comment)

There are messages in that ACARS list that relate exclusively, specifically, to the inertial reference systems.

I understand that the ADIRUS are composed by Air Data Units (then airspeed would obviously play a role) and Inertial Reference Units (which don't have air data as input).

PJ2

17th Jun 2009, 16:15

YRP:
Let's be serious here. Accidents are not investigated by the court of public opinion. Does anyone here know whether the ACARs messages are transmitted reliably, or lossy? What is the transmit order, same as events, or based on priorities? How does the timestamping work? Specifically what messages does Air France enable/disable? What about messages that have _not_ been reported (eg excess cabin altitude)? Would there have been one, or is there no message for that event?
Precisely.

BOAC:
Thanks - you're right.

AJ:
Here's a description of the ADIRS:

The Air Data and Inertial Reference System (ADIRS) supplies temperature, anemometric barometric and inertial parameters to the EFIS system(PFD and ND) and to other user systems (FMGC, FADEC, PRIM, SEC, FWC, SFCC, ATC, GPWS, CMC, CPC).
The system is comprised of:
– three identical ADIRU's (Air Data and Inertial Reference Units). Each ADIRU is divided in two parts, either of which can work separately in case of failure in the other :
• the ADR (Air Data Reference) part which supplies barometric altitude, speed, Mach, angle of attack, temperature and overspeed warnings.
• the IR (Inertial Reference) part which supplies attitude, flight path vector, track, heading, accelerations, angular rates, ground speed, vertical speed and aircraft position.
The ADIRU gives the true heading instead of magnetic heading :

– above 82° North
– above 73° North between 90° and 120° West (magnetic polar region)
- above 60° South
– one ADIRS control panel located on the overhead panel for modes selection (NAV, ATT, OFF) and failure indications.
– 2 GPS receivers, which are connected to the IR part of the ADIRU's for GP/IR hybrid position calculation.
– four types of sensors :
• pitot probes (3)
• static pressure probes (STAT) (6)
• angle of attack sensors (AOA) (3)
• total air temperature probes (TAT) (2)
These sensors are electrically heated to prevent from icing up.
– eight ADMs (Air Data Modules) which convert pneumatic data from pitot and static probes into numerical data for the ADIRUs.
– a switching capability for selecting ADR3 or IR3 for instrument displays in case of ADIRU 1 or 2 failure.
– a MAG / TRUE pushbutton switch, used during polar navigation.
– AC BUS provides to normal electrical supply. DC BUS provides a back up possibility through an inverter.

Hope this helps!

FrequentSLF

17th Jun 2009, 16:36

RWA

Why on earth aren't the autopsy results being passed on to the investigators? Apart from anything else, they'll be absolutely crucial in deciding whether the victims died in the air or in the sea?

It might be that the Brazilian coroner before passing the results wants to be 100% sure of them, just to avoid unneeded speculation?

RatherBeFlying

17th Jun 2009, 16:46

Whatever happened to the rest of the structure, this bit of a galley seems not to have been subjected to major forces. It even looks like the trash bin stayed attached with some contents.

Possibly it went below the surface with the external structure it was attached to, came loose and floated back up.

DorianB

17th Jun 2009, 16:51

Link to deleted (among other) photos:

Pictures by DorianB - Photobucket (http://s635.photobucket.com/albums/uu79/DorianBanks/?newest=1)

DorianB

17th Jun 2009, 16:59

Pulled up by Fragata Constituição (http://www.flickr.com/photos/niloaurnheimer/2991301089/) yesterday.

RuudA

17th Jun 2009, 17:10

Originally posted by BOAC:
There have been several (I think unanswered) requests here for positions of the groups of bodies found. Do we have any, and has anyone back-plotted the position of the second recovery vis a vis ocean currents to see where they would have been in relation to the first, and likewise for the first to the POSSIBLE crash site?

My answer:
The Brazilians gave information about the location of bodies on 9 and 16 June.
In the next picture I have combined this two pictures (orange spots = 9 June; red spots = 16 June).
http://img.ruudabeln.nl/090616dia3.jpg
In this picture I also give the possible drift of the bodies (in yellow)
(see debris and impact-location #1374) (http://www.pprune.org/rumours-news/376433-af447-69.html#post4994350))

YRP said:
Even if this information were available, I think it would be difficult to analyze properly. Most people here are not experts on ocean currents. An earlier post mentioned diverging surface currents in the area, ...... backtracking currents to the crash site sounds at least tricky if not completely unreliable.

I totally agree with YRP.
I know that even for a specialist this backtracking takes a lot of time and is difficult and uncertain.

But nevertheless we don't have a lot of time to find the black box.
And this forum can maybe answer the next question:
Simple backtracking shows a discrepantion between the possible impact-location and the location of ultimo ACARS report: is that possible?

Will Fraser

17th Jun 2009, 17:10

petermcleland it is the same, sloppy knots and all

petermcleland

17th Jun 2009, 17:19

Will Fraser

"petermcleland it is the same, sloppy knots and all"

No I don't think so Will,...It seems to have a clean and undamaged internal structure (top of picture), as opposed to the ragged and torn parts of the VS root structure that we have seen before.

ACLS65

17th Jun 2009, 17:33

petermcleland: I think the base of the VS and debris are just cut off in those pictures making it look like there is a clean edge. I believe the angle of the rudder is the same. Hopefully we are only missing one AC in that area.

DorianB

17th Jun 2009, 17:35

AF447 Pictures (http://photobucket.com/af447)

BOAC

17th Jun 2009, 17:37

Thank you, RuudA - very informative. I cannot quite understand the 'drift', and what are the 2 unlabelled orange dots?

One would hope that oceanographers can do something there. Time is running out.

If the white circle is the focus of the search area I hope they have good reason for siting it on the floating fin.

venux

17th Jun 2009, 17:45

pattern_is_full said:
2. The cabin altitude warning seems equivocal. Plane decompresses - or - plane rises 2,000 ft. in 20 secs. in a convective updraft - or - plane drops 2,000 ft. in 10 secs. in a convective downdraft - or - plane ascends/descends rapidly for some other reason. Would not any rapid altitude change in either direction that exceeded the pressurization/venting system's ability to keep up lead to this warning?

That would NOT be the case if the warning message indicates that plane altitude is in danger of overtaking cabin altitude, as was stated early in the thread. *IF* that is the true meaning of the warning message, then at 0214z the plane had just started a rapid descent, with an intact cabin, at an angle that still permitted the sending of the ACARS message.

md80fanatic

17th Jun 2009, 17:51

It's puzzling to find such a large internal structure (portion of galley), without finding any smaller pieces of the same obviously buoyant material that it was attached to. Like finding a bedroom closet in the middle of the woods, with no bedroom in sight.

Of all the items on an aircraft, the galley is nearly the last item I'd expect to still be floating after 16 days. Since it was, I am surprised there isn't more of this plane to be found within eyesight of this piece (subject to the exact same currents)?

More data brings exponentially more questions.

PJ2

17th Jun 2009, 18:13

md80fanatic;
More data brings exponentially more questions.
Yes it does, in terms of "how", but large chunks of intact wreckage, (especially the latest made available/linked to by DorianB) mean that there was not a high-speed collision with the water as was the case with SW111.

The airframe broke up sufficiently to permit large pieces to exit relatively free of damage from other large pieces. We do not know when or how this occurred. "Shrapnel" damage is visible on many of the large sections, which would be expected. The nature of these telltale markings may, with hard sleuthing, indicate something about a breakup pattern....or not.

With careful examination regarding any part number markings or with drawings, many of the collected parts' location in the airframe may be determined. At this point, very little can be known about location of anything we now have photos of.

I think we can say all this with some reliability now, but regarding airframe breakup we cannot answer the questions:

- At what altitude(s) did the initial breakup occur or was it upon contact with the sea?

- What broke free first? (Evidence of the horizontal stabilizer, wing parts and engine cowlings, (same honeycomb material) have not been found, nor have wheels, (I say this only because there is a photo of a bogie floating free in the Abijan accident discussed earlier in this thread - I realize this may be a smaller possibility here).

- When did the VS break free?

- The question of further ACARS data has been asked, but not answered.

- An far-fetched question might be asked about what, if anything, did satellites see at 02:14+ Z in terms of a flash or anything else unusual. Just haven't seen any comments re this.(dealt with below).

Been Accounting

17th Jun 2009, 18:21

The galley is made of Honeycomb structure which contains sealed air pockets.

In addition there are Standard Units still in the galley structure. I don't know how well sealed they are but I imagine that it would be easy to trap (say) 100litres of air in the whole structure.

Hence the galley (liberated from the trolleys) floats. Look how high it is out of the water.

http://i635.photobucket.com/albums/uu79/DorianBanks/echo.jpg

Why just this galley (5 Trolleys - Door 2?) and not others??????

captains_log

17th Jun 2009, 18:21

MD80 Fanatic

Of all the items on an aircraft, the galley is nearly the last item I'd expect to still be floating after 16 days. Since it was, I am surprised there isn't more of this plane to be found within eyesight of this piece (subject to the exact same currents)?

Exactly my initial thoughts, we are all aware of the effects of an object of this mass hitting water at such velocity is comparable to hitting terra firma.
Some input from experienced investigators would be preferable, what's the PROBABLE result of:

1. Mid air break up/ high altitude
2. High velocity /high angle impact
3. Low velocity/low angle impact.

Due to my limited experience id rather not be shot down for making an uneducated speculation at how the galley has somehow been thrown clear or survived a potential heavy impact, at the same time it seems most of A/C sank. Otherwise we would of expected a considerable amount of boyant debris. With non boyant objects sinking.
Decomposition happens slower in water but bodies should eventually float. Surely they're contained in the A/C still? Surely some of the wheels stayed intact, that's alot of bouyancy.

PJ2

17th Jun 2009, 18:24

PN;
I thought that that would not have been possible given the states ITCZ activity.
Almost certainly you're right - anything unusual would be obscured by cloud etc - just casting about at this point.

ClippedCub

17th Jun 2009, 18:25

We still can't conclude an in-flight break-up with the evidence at hand. Though I think speculation leads to a more thorough understanding of one's equipment, and is therefore healthy, some here would jump on you for speculating that this is an in-flight break-up.

Gringobr

17th Jun 2009, 18:31

Bodies may float if they do not have ruptured stomachs
Once ruptured, or after decomposition which may take up to 3-4 weeks, they will sink... which is why the big rush was on to find them, and fewer (only one yesterday) are being found.
Autopsy reports also state it is probable that the aircraft hit the water in a near horizontal position because of the majority of 4 fracture type injuries, (ie virtually no head injuries)
Google FAB, the Brazilian Air Force site they have daily press releases and photos in English

DorianB

17th Jun 2009, 18:36

Clickable thumbnails:

http://i635.photobucket.com/albums/uu79/DorianBanks/th_charlie.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=charlie.jpg)

http://i635.photobucket.com/albums/uu79/DorianBanks/th_fox.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=fox.jpg)

http://i635.photobucket.com/albums/uu79/DorianBanks/th_echo.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=echo.jpg)

http://i635.photobucket.com/albums/uu79/DorianBanks/th_bravo.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=bravo.jpg)

Pontius Navigator

17th Jun 2009, 18:37

how the galley has somehow been thrown clear or survived a potential heavy impact, at the same time it seems most of A/C sank.

Or has not yet been located.

Otherwise we would of expected a considerable amount of boyant debris. With non boyant objects sinking.

The obvious freeboard of this galley portion could lead to a significant dispersal with respect to debris that is fully waterborne and not exposed to the wind.

Decomposition happens slower in water but bodies should eventually float. Surely they're contained in the A/C still?

This is a key fact and relevant to the 9/16 Jun positions.

Surely some of the wheels stayed intact, that's alot of bouyancy.

But only if they became detached from the rest of the structure. Remember also that wheels are dark and thus more difficult to spot than the wreckage we have seen so far.

overthewing

17th Jun 2009, 18:39

To my untutored eye, the pieces of the plane that have been retrieved seem to be in remarkably good condition, and also remarkably large. Having looked at photos from crash sites (on the ground) over the years, I often get the impression of the plane being shattered into tiny pieces. If my impression is at all accurate, this fragmentation is presumably due to a violent collision with the ground? The ocean is no less hard when you hit it, so does this tell us anything about the impact made by AF447?

PJ2

17th Jun 2009, 18:40

ClippedCub;
some here would jump on you for speculating that this is an in-flight break-up.
Yes, understand - though I tried to stay away from "concluding", it can read like that, so guilty as charged and being taken to task would be fair game I think. The alternatives are expressed below in another's post seems to cover all bases...

At the same time, we have large chunks and not a SW111 wreckage pattern so there is at least something in that. Post modified, with thanks.

grizzled

17th Jun 2009, 18:45

Given that speculation is part of what this forum and this thread are about, the most accurate speculation (though that term in itself can be problematic) that can be done in most situations like this, is to speculate on what things, with given facts, most likely are NOT true. Informed speculation (as has been previously mentioned) often provides an investigator with assistance in where to look and what to look for.

I may have missed somehting (as I often do . . ) this morning, but I haven't seen anyone say that the new pix lead us directly to inflight break up. Using the process I mentioned above, the size and condition of the portions recovered in the recent pix do lead us away from the notion of a high speed / high angle impact with the surface.

Investigators will indeed be ticking off a few boxes as we write these things. But in almost all instances they will be ticking the box that says "Not Likely" rather than the box that says "Likely". And, over the next few weeks and months, they will continue to do so -- very slowly, and very carefully.

lomapaseo

17th Jun 2009, 18:58

PJ2

"Shrapnel" damage is visible on many of the large sections, which would be expected

I go for hours without reading this thread but from the posts so far it appears that the posters are referencing photos etc. that are now deleted.

I agree that much can be discerned by examining the photos against experience although the best we might do is decide how much it broke up in the air.

Your use of the word shrapnel is intriguing. I tend to use that word only in describing impacts to a structure from smaller individual objects moving at a much higher velocity and from a funnel source(explosive blasts, uncontained engine bits etc.) In the event of a breakup either in the air or against the water the velocity gradient between major parts is not as pronounced and scaring and longitudinal (along the axis of flight) gouging is more evident.

If you could point to a photo of what you meant I could understand better.

Will Fraser

17th Jun 2009, 18:59

The Galley structure is likely not a part of fuselage 'architecture'. Its shape and appearance as 'infill' or 'appurtenant' structure and its seeming lack of freefall through high speed airmass or high speed impact need some noodle work. Perhaps it may have been 'sheltered' at impact and floated free of a substantial part of the hull post impact with the sea?

takata

17th Jun 2009, 19:05

@RuddA
The debris fields are already maped and numbered by the BEA.
See here:
http://www.bea.aero/fr/enquetes/vol.af.447/recherches.en.mer.pdf

The comment including facts is quite short and in French:
Bureau d'Enquêtes et d'Analyses (http://www.bea.aero/fr/enquetes/vol.af.447/com17juin2009.php)

S~
Olivier

captainflame

17th Jun 2009, 19:07

Orange spots are sites of debris recovery (derived from "tail fin" tag on map)

"Ultimo reporte" is likely to be the last VHF transmission or reporting point when leaving the Brasilian radar controllers. This is when they transmitted estimating TASIL 50 min later (transmitted at 01:33 for TASIL at 02h23).
This transmission may have also included the turbulence report. (unless it was just a bit ealier). This was not explicit from BEA daily briefings from last week...

PJ2

17th Jun 2009, 19:09

lomapaseo;
I am using the word "shrapnel" here to describe smaller pieces hitting larger pieces in a break-up sequence but am not implying or conveying anything more than that.

The word is perhaps the wrong one to use in this case as it may imply an "explosion", which is not what I am trying to convey.

Rather than post photos I can refer you to the F/A seating structure, the spoiler panel, the structure with the video screen attached, for example, where there are both fractures and marks which may be the result of that structure being struck by other parts.

If hypothetically we found blue or red paint on some parts, we could surmise that they had come into contact with the fin, for example. That's the kind of thinking. I am not saying this is the case with anything - I'm just using this as an example.

Whether such accident investigation analysis would yield meaningful information is wholly uncertain given the tiny collection of structure available but it is a technique used. I am not an AI but am familiar with some of the processes.

Captain Airclues

17th Jun 2009, 19:39

overthewing

If you descend with a blocked pitot then the aircraft will rapidly exceed Vne, unless the pilots fly 'attitude'. The reason for this is that the pitot pressure remains the same whereas the static pressure increases, causing underreading of the speed. I have tried this on the simulator, descending with a constant IAS (not all simulators have this function), and Vne was exceeded after about 5000ft.
Conversely if the aircraft climbs at constant speed with a blocked pitot then it will stall unless attitude flying is used.

Dave

Flyinheavy

17th Jun 2009, 19:51

@LostInSaigon:

1) Descending to warm air would mean a huge fuel penalty. They only have enough fuel to reach their destination at cruising altitudes. Descending even for a short time would mean they would not have enough fuel to complete the flight

Correct me, if I am wrong, but reaching my destination, would be the least of my worries in that situation.

As far as I have seen the ISIS has the Altimeter included, so not so sure about Stby Altm.

Just my impression......

thesandbox

17th Jun 2009, 19:55

I'm wondering, Poison's message aside, has anybody fed the sequence of
ACARS into a simulator to see what the result is? Either in reverse order of received, or in order listed on the ACARS message. Does one message trigger the next one in line? At what point does the aircraft simulator become uncontrollable or unrecoverable? Factor in the weather, turbulance, etc.
You should have some sort of idea as to what happened in what sequence and what type of break up they were looking at?

and

1)Without knowing what triggered the ACARS messages, how could you feed this into a simulator? (Assuming simulators have a total ACARS simulation which they do not).

....but can they, and have they, compared the initial ACARS messages, possibly the ones with the initial problem, with those of the other 4 or so known and mentioned very similar cases with the pitot tubes... Yes in the other incidents the pilots were able to regain control after a couple of minutes but I would think if the problems all arose from the same cause then the initial ACARS messages of those incidents during that time would be the same or very similar. They surely have a maintenace log of those. Have not seen anything on this yet...

BigHitDH

17th Jun 2009, 20:00

lomapaseo, PJ2,

I find your "shrapnel" comments interesting, I had the same thought when I first studied photos of the VS.

Take a look at this shot: http://www.fab.mil.br/portal/voo447/FOTOS/080609/foto_3.jpg

I can see 3 "cuts" in the leading edge of the VS, anyone else concur?

quaeler

17th Jun 2009, 20:15

LIS -
1) Descending to warm air would mean a huge fuel penalty. They only have enough fuel to reach their destination at cruising altitudes. Descending even for a short time would mean they would not have enough fuel to complete the flight.

This is the purpose of both discretionary extra fuel and Dakar.

captainflame

17th Jun 2009, 20:16

As written (by me among others) in previous posts, the ISIS is a self contained instrument providing Airspeed from stby pitot, attitude from internal gyros, Altitude from STBY static ports, and slip/skid info from accelerometers,

ISIS IS the stby instuments ! :ok:

direct inputs from the pitot and from the static ports are provided. No computer inbetween !!

Also, the FMGC provides a "backup altitude" which is provided from the GPSs on the DATA / GPS page. It's not a pressure altitude, but nevertheless gives a good idea of whether you are at 35000' or 2000' !!

The QRH checklist for "Unreliable airspeed" suggests to use this it by the way.

please read the important info provided on the thread so IT is not clogged with redundant, already asked and answered questions !:ugh:

thesandbox

17th Jun 2009, 20:24

Will Fraser

17th Jun 2009, 20:25

BigHitDH - with its poor resolution, that photo doesn't contribute to me what you see.

The Galley is installed as a unit (module) at the plant, so its strength is intrinsic, but well short of a/c substructure design. It may well have been robust enough to resist fragmentation while falling (free, on its own), but probably not strong enough to resist high speed air mass. If a/c underwent some sort of structural compromise of the pressure hull, doesn't mean it didn't remain substantially complete to enter the water at a velocity much lower than that experienced at cruise.

Pontius Navigator

17th Jun 2009, 20:28

aguadalte

17th Jun 2009, 20:32

Quote:
Originally Posted by overthewing http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/buttons/viewpost.gif (http://www.pprune.org/rumours-news/376433-af447-93.html#post5004157)
This is doubtless a dumb set of questions; if so, I apologise.

If you're flying the plane, and all the computers suddenly throw in the towel, is there any way of knowing what altitude you're at?

If you suspect that the problem is iced-up pitots, would descending to a lower altitude in order to unblock the tubes be sensible, or not?

Is there any way to know that you're a lot closer to the ocean than you'd like to be?

I sense that you are suggesting they possibly descended to find warm air to melt the frozen pitot tubes and then possibly impacted the ocean because they didn't know their altitude.

1) Descending to warm air would mean a huge fuel penalty. They only have enough fuel to reach their destination at cruising altitudes. Descending even for a short time would mean they would not have enough fuel to complete the flight.

2) The standby altimeter relies on barometric pressure only and will continue to give accurate readings even with total electric or computer failure.Lost,
I'm very sorry but I have to disagree:
ETOPS flight planing has legal requirements for fuel reserves in case of In-flight Engine Shut Down, plus, de-pressurization (one or two engines running) to reach ETOPS suitable alternate aerodromes. In warm air (equatorial area) one reaches positive TAT readouts between 20 to 15000, and I'm sure a very positive TAT at about 10000'. In the event a pilot decides to descent for safety reasons, there is no pressure to continue to destination. Commercial interests, always come after safety. He may latter decide to climb again, but the decision process to resolve a failure is far more important than to comply with time-tables.
Flyinheavy:
As far as I have seen the ISIS has the Altimeter included, so not so sure about Stby Altm. I tend to agree with you. And in my very humble opinion, without IR's and a faulty ISIS, they would not have the slightest chance to keep control of the aircraft.

Graybeard

17th Jun 2009, 20:40

Haven't seen it mentioned. What would be the expected CG at cruise?

Some of the data are consistent with a flat spin.

GB

SaturnV

17th Jun 2009, 20:41

From the Air India 182 investigation report:

The [floating]wreckage consisted mainly of various leading edge skin panels of the left and right wings, left wing tip, spoilers, leading edge and trailing edge flaps, engine cowlings, flap track canoe fairing pieces, landing gear wheel well doors, pieces of elevator and aileron, cabin floor panels, cabin overhead and upper deck bins, passenger seats, life vests, slide rafts, hand baggage, suitcases, personal effects and a number of internal fittings. The floating wreckage constitutes about three to five percent of the aircraft structure.
................

The wreckage was then transported from Ireland to Bombay, India where it underwent further examination by the Floating Wreckage Structures Group which then produced a report which was submitted to the Indian Inquiry. The report concluded:
- There was no evidence of fire damage.
- There was no evidence of lightning strike damage.
- The cabin floor panels from the forward and rear sections of the aircraft separated from the support structure in an upward direction (floor to ceiling) pulling free from the attaching screws and, in some cases, breaking the vertical web of the seat track/floor beams.
- The position of the leading edge flap rotary actuator and the damage to the flap structure indicated that the leading edge flaps were in the retracted position.
- The six spoiler actuators found were in the retracted position. The lower surface of all the spoiler panels showed signs of spanwise skin splits with the edges curled into the core of the honeycomb. The report concluded that this was possibly due to the loading of the spoilers by being deployed in flight at high speed, resulting in compression on the lower surfaces. This, in turn, caused splitting of the lower skin into the honeycomb.
- The right wing root leading edge, number 3 engine inboard fan cowling, the right inboard midflap inboard leading edge, and the right stabilizer root leading edge all exhibited damage possibly due to objects striking the right wing and stabilizer before water impact.

In addition to the above conclusions, the following significant information regarding the floating wreckage is noted in the report:
- The aircraft was carrying a -7Q engine at the 5th pod and a -7J 5th pod kit in the aft cargo compartment. In all there were 14 engine fan cowls (four in the aft cargo compartment). Out of these 14 fan cowls, nine, including six from the working engines and three from the aft cargo compartment, and two additional pieces of fan cowls were found. Five of the fan cowls from the working engines showed folding damage lines at about the three and nine o'clock positions. The number 3 engine inboard fan cowl had severe impact damage on its leading edge and had small outward puncture holes but no penetration through the outer skin in the lower centre region. The two fan cowls of the -7J 5th pod kit stowed in the aft cargo compartment showed severe damage. One piece was cut at one corner in an arc of about 20 inches diameter and its external skin was peeled back.

- The cockpit entry door and the side bulkhead panel were found relatively intact but had come out of their attachments.
- Twelve toilet doors out of 16 were found and were relatively intact but had come out of their attachments.
- Cabin interior panels and overhead bins of the main and upper decks which were recovered exhibited only minor damage.
- The wooden boxes which contained the fan blades of the 5th pod engine were loaded in container 24L in the forward cargo compartment and were found broken apart exhibiting no burn marks.
- One passenger oxygen bottle and one portable oxygen bottle were recovered and showed no sign of damage.
.....

- Two pieces of the cover of an overhead locker originating above either door 2R or 4R were also found on the foreshore [of Wales]. They were partially damaged and blackened by fire. Mr. Clancy [an explosives expert] concluded that this indicated the presence of fire.

The CASB in its examination of the floating wreckage noted the following:
- The fan cowls of the number 4 engine had a series of five marks in a vertical line across the centre of the Air India logo on the inboard facing side of the fan cowl. These marks had the characteristic airfoil shape of a turbine blade tip. It is possible that a portion of the turbine parted from the number 3 engine and struck the cowl of the number 4 engine.
- The upper deck storage cabinet which was located on the left side had unusual damage to its bottom. A large rounded dent in the bottom inboard edge of this stiff cabinet structure revealed smooth stretching without breakthrough. The damage did not seem to be achievable by inertia or impact forces as the cabinet except for the bottom was undamaged. The damage was considered by a CASB investigator to be compatible with the spherical front of an explosive shock wave generated below the cabin floor and inboard from the cabinet; however, it is not known if this damage could be caused by some other means.
- The right wing root fillet which faired the leading edge of the wing to the fuselage ahead of the front spar had a vertical dent similar to that which would have resulted had the fillet run into a soft cylindrical object with significant relative velocity. The paint on the inboard chord appeared to be scorched brown in the centre areas of three honeycomb panels. It has been determined that sudden heat can turn these panels brown, but it is not known if other reasons for the discolouration exist. The fillet abutted the fuselage side at the aft end of the forward cargo compartment.

Would seem a greater variety of wreckage recovered from AI182 than from AF447, and more helpful to the investigators with respect to the sequence.

SaturnV

17th Jun 2009, 20:54

Air India 182 autopsy results.

2.9 Medical Evidence
Medical examination was conducted on the 131 bodies recovered after the accident. This comprises about 40 per cent of the 329 persons on board. It should be noted that assigned seating is based on preliminary information. Also, the exact position of passengers is not certain because it is not known if passengers changed their seats after lift-off. On the information available, the passengers were seated as follows:

Passengers:*
Seats Available Occupied Bodies Identified

Zone A 16 1 0
Zone B 22 0 0
Upper Deck 18 7 0
Zone C 112 104 + 2 29
Zone D 86 84 + 1 38
Zone E 123 105 + 3 50
SUB-TOTAL 377 301 (+6 infants) 117
Crew:
Flight Deck 3 3 0
Cabin 19 19 5
TOTAL 399 329 122

There were 30 children recovered and they showed less overall injury. The average severity of injury increases from Zone C to E and is significantly less in C than in Zones D and E.

Flail pattern injuries were exhibited by eight bodies. Five of these were in Zone E, one in Zone D, two in Zone C and one crew member. The ignificance of flail injuries is that it indicates that the victims came out of the aircraft at altitude before it hit the water. There were 26 bodies that showed signs of hypoxia (lack of oxygen), including 12 children, 9 in Zones C, 6 in Zone D and 11 in Zone E. There were 25 bodies showing signs of decompression, including 7 children. They were evenly distributed throughout the zones, but with a tendency to be seated at the sides, particularly the right side (12 bodies).

Twenty-three bodies showed evidence of receiving injuries from a vertical force. They tended to be older, seated to the rear of the aircraft (4 in Zone C, 5 in Zone D, 11 in Zone E, 2 crew and 1 unknown), and 16 had little or no clothing. Twenty-one bodies were found with no clothing, including three children. They tended to be seated to the rear and to the right (3 in Zone C, 5 in Zone D, 11 in Zone E and 2 unknown).

There were 49 cases showing signs of impact-type injuries, including 19 children (15 in Zone C, 15 in Zone D, 15 in Zone E, 1 crew member and 3 unknown).

There is a general absence of signs indicating the wearing of lap belts. Pathological examination failed to reveal any injuries indicative of a fire or explosion.
*See Appendix C for interior seating arrangement.

From a report of flail injuries from use of ejection seats:
Q forces are related to indicated airspeed rather than true airspeed. These forces increase with the square of the velocity thus producing the recommendation that pilots should reduce airspeed and increase altitude prior to ejection (3). Q forces have been divided into those produced by windblast, resulting in injuries such as petechial and subconjunctival hemorrhage, and those injuries produced by flailing of the head and extremities. Flail injuries are the result of the differential deceleration of the extremities in relationship to the torso and seat. Flail injury occurs as a consequence of the extremities leaving their initial position, building up substantial acceleration, and then suddenly stopping. The sudden stop may produce a bone fracture, joint dislocation, or total disarticulation.

The Brazilian autopsy reports are suggestive of numerous bodies with flail injuries.

Coyote44

17th Jun 2009, 21:21

Should'nt you consider TAT rather than OAT??? What do you think the TAT was??

protectthehornet

17th Jun 2009, 21:36

You two are the only people on this thread worth reading.

and given a choice between descending and getting my pitot tubes back and using more fuel or NOT getting my pitot tubes back and dying...what is wrong with this question.

I haven't left North America in my flying. But I have had to fly below the Flight Levels in jet transports for various reasons...the fuel penalty isn't that great...it is doable,manageable etc.

GEE GUYS (not dc8 and clues) ...what happens if you lose pressurization...and have to fly at 10,000feet!

shaking my head at some of the stuff I see.

lomapaseo

17th Jun 2009, 21:51

I can see 3 "cuts" in the leading edge of the VS, anyone else concur?

I finally downloaded and collected all the pics that managed to survive the posts here (probably only 20%). This makes it a little easier to reference comments back to a pic.

My quick look at the VS leading edge does shows the cuts that you refer but I could' only resolve those if I had a pic 0.5-1.0 X. Somebody with a before pic (airliners net?) might confirm if they they're before hand. Otherwise I would suspect rope lashings to recover the part.

I now see what PJ2 was referring in his posts. Most of what I see are breakups and scarring at relatively low speed not a dive into the water.

I tend to go along with the reports from the somebody close to the investigation that the aircraft broke up partially before it hit the ground (like AI, SA, PA103, TWA800 etc.). However many of the photos are probably from parts that stayed with the larger aircraft sections until they struck the water at freefall speed (significant drag so their terminal velocity would have been low).

Thus I suspect that allowing for some drift the rest of the plane is in the begining of the drift area where parts like the galley and crew rest seats were found.

For any of you water borne experts out there. Is it practical to plant a couple hundred floating bottles (or rubber ducks) out there and track where they end up in several days just to confirm how far the currents might have moved them until they were recovered? Forget the underwater currents, the stuff that I have seen never got more than a few feet below the surface (no signs of hydraulic loading)

of course the investigators are way ahead of us internet folks on this stuff.

DorianB

17th Jun 2009, 21:56

I believe I have most pics in the URL below - if anyone knows of (relevant) missed ones please PM me the URL:

AF447 Photos (http://photobucket.com/af447)

lomapaseo

17th Jun 2009, 22:03

DorianB

I believe I have most pics in the URL below - if anyone knows of (relevant) missed ones please PM me the URL:

Yes indeed you have the best collection I have seen:ok:

You are a great help to folks like me that devour photos for confirmation of speculations.

I wonder where Machaca is he usually has great sources for this kind of stuff

ettore

17th Jun 2009, 22:29

This link redirects you to the picture, not to the report (sorry, I did try to insert the pic itself but I couldn't):

The Associated Press: Autopsies suggest Air France jet broke up in sky (http://www.google.com/hostednews/ap/slideshow/ALeqM5iOegnahAFcEgwJZ4WKGkVz9Dgq5wD98SL8A80?index=1)

http://www.google.com/hostednews/ap/slideshow/ALeqM5iOegnahAFcEgwJZ4WKGkVz9Dgq5wD98SL8A80?index=1

This photo released Wednesday June 17, 2009 by the French army shows soldiers approaching a piece of debris believed to be part of Air France flight 447, during continuing searches for debris and bodies on Friday June 12, 2009 in the Atlantic Ocean. Air France Flight 447, en route to Paris from Rio de Janeiro with 228 passengers and crew, went down in the ocean on June 1. (AP Photo/ECPAD) NO SALES

aguadalte

17th Jun 2009, 22:32

protectthehornet:
and given a choice between descending and getting my pitot tubes back and using more fuel or NOT getting my pitot tubes back and dying...what is wrong with this question.

I haven't left North America in my flying. But I have had to fly below the Flight Levels in jet transports for various reasons...the fuel penalty isn't that great...it is doable,manageable etc.

GEE GUYS (not dc8 and clues) ...what happens if you lose pressurization...and have to fly at 10,000feet!

shaking my head at some of the stuff I see.
Extended Twin [Engined] OPS require a certain amount of extra fuel to cope for Inflight Engine Shut-Down and Depressurization. This means that, if one has to descent to 10.000ft in any phase or part of the flight, one is assured to have enough fuel to reach a suitable alternate airport.

Having that in mind, if a pilot gets (yes it shows on ECAM) a failure of pitot heat, (and is unable to reset or cope with the situation) one can elect to descend to a lower altitude. TAT is the reference temperature to have in mind in such case and a descent to about 15 to 10000' will be enough to get rid off the icing conditions.

Again, in my opinion, they didn't have enough conditions to do it, due to lost of visual and attitude indications. (it doesn't mean they haven't tried it...)

I honestly think that we are loosing the big picture here. What we need to find out is why did that crew elected (or not) to fly into the bad weather and what happened to produce such a great deal of failures, with especial emphasis to [all] IR's and (partially, at least) to the ISIS. The rest is only a consequence, not the reason.

An A330 (or any other aircraft) is not flyable (at night, in weather) without attitude indication. The A330, in particular, may be flown without Flight Control Computers (PRIM's and SEC's), with an Hydraulic Double Failure, in Emergency Electrical Configuration, even without both engines (for a certain period of time, of course), but the failure of ALL IR's and ISIS is unquestionably problematic.(I know this is pure speculation, but - lets face it - that's what we are all doing here).

Just my two cents...ready to be flamed.

Edit to say, in my defense: if those IR's were not failed, why didn't we had a positive and unquestionable statement of Airbus Industrie mentioning a "partial failure"?

broadreach

17th Jun 2009, 22:48

Quote
Is it practical to plant a couple hundred floating bottles (or rubber ducks) out there and track where they end up in several days just to confirm how far the currents might have moved them until they were recovered? Forget the underwater currents, the stuff that I have seen never got more than a few feet below the surface (no signs of hydraulic loading)
Unquote

It would probably have been a good a idea to drop transmitter-equipped markers where wreckage or bodies were found, early on in the search. The aircraft that found the wreckage may well have done so, though I haven't seen any reference thereto. Bodies would have similar buoyancy and would tend to drift reasonably closely; objects like the galley, with much more windage, would be more subject to localised winds.

Obviously, the longer any collection of flotsam floats, the more it's likely to disperse, particularly so where the aircraft went down.

scriabh

17th Jun 2009, 22:57

I'm sure that the oceans are being monitored (and not by plastic water bottes) to collect data -- there is a lot of monitoring stations that give real-time data on ocean currents -- probably not in this area, and there are a lot of computer models. I am sure that data is being collected by the ships as they trawl for debris to get real-time data -- depth and surface information. again, something I know a fair bit about. my posts keep being deleted.

BigHitDH

17th Jun 2009, 23:03

Broadreach, Lompaseo,

Funny you should use ducks as an example, it reminded me of the "Friendly Floatees" accident that actually turned into a very valuable piece of science, makes for an interesting read:

Friendly Floatees - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Friendly_Floatees)

Dutch Bru

17th Jun 2009, 23:18

The "cuts" were already there before any ropes appliance:

foto_3.jpg picture by DorianBanks - Photobucket (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=foto_3.jpg)

And also on 14-05-2009 (need to save pic and magnify):

Airbus A330-203 - F-GZCP (Air France) par Jean-marc DAVID | Pictaero (http://www.pictaero.com/fr/pictures/picture,42364)

Starter Crew

17th Jun 2009, 23:19

if a pilot gets (yes it shows on ECAM) a failure of pitot heat...

Would a pitot heat failure produce any associated ACARS message or is the relevant message likely to be tied to those downstream components (e.g. ADIRU) as a start point for maintenance activity after flight?

DorianB

17th Jun 2009, 23:21

Here is a shot a day before the crash...showing the missing paint on the leading edge:

Photos: Airbus A330-203 Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/Air-France/Airbus-A330-203/1539421/L/&sid=fe8211c78d9b6ddbfd0db374397515ea)

A33Zab

17th Jun 2009, 23:21

Dazdaz:
Anyone know the engine manufacturer on this a/c?

GE CF6-80-E1A3

But will it make any difference?

DADDY-OH!

17th Jun 2009, 23:28

Starter Crew

Yes, an ECAM message relating to the Capts/F/O's PHC (Probe Heat Computer) would be flashed via ACARS in sequential order with other detected failiures.

Lost in Saigon

17th Jun 2009, 23:37

lomapaseo

17th Jun 2009, 23:40

scriabh

I'm sure that the oceans are being monitored (and not by plastic water bottes) to collect data -- there is a lot of monitoring stations that give real-time data on ocean currents -- probably not in this area, and there are a lot of computer models. I am sure that data is being collected by the ships as they trawl for debris to get real-time data -- depth and surface information. again, something I know a fair bit about. my posts keep being deleted

OK, so even without rubber ducks do you agree that they should now have a better idea where the big heavy stuff should be? Assuming of course that the location of some of the pieces of the found debris probably came from the aircraft when it hit the water in a free fall trajectory.

I'll check back more often for a reply lest you get deleted again :)

Mike-Bracknell

17th Jun 2009, 23:51

Why haven't the French Navy found the CVR/FDR's? Won't their batteries be getting exhausted by now?

Just what I was thinking - surely a towed array sonar can detect deliberate sonar pings from hundreds of miles away, so given the deployment time surely they'd at least have detected the pings by now, even if they've not pinpointed it?

Sawbones62

18th Jun 2009, 00:14

Considering the effects of average current or winds alone won't explain the dispersal of the floating wreckage. The pieces will move at different rates and directions depending on their size and shape - what sort of "sail" and "keel" is presented to the wind, waves and current will determine what will move in which direction. Each piece floating aircraft wreckage piece is uniquely asymmetric as compared to "Floaties" and likely less predictable in current or original location.

Nature gives an example in Vellela vellela (http://www.montereybayaquarium.org/animals/AnimalDetails.aspx?enc=VsGX+Lst7QbsYfiv29EAGQ==)- the By-the-Wind Sailor jellyfish. The are hatched far out to sea, half with "left-handed" sails and half with "right-handed" sails. In the Pacific, those with right-handed sails wash ashore in California, those with left-handed sails in Asia.

BreezyDC

18th Jun 2009, 00:14

For a forum that offers items that "may be of interest to interest to professional pilots" those on this thread certainly have a lot of interest in less pertinent details like the state of bodies, wreckage and parsing failure modes with incomplete information. I'd expect more interest in some of the lessons learned that effect us all, such as:

Use of radar for storm detection, especially above the radar top where ice crystals are less visible (touched on early in thread);
SOPs and issues when dealing with inconsistent flight data readings (covered by some more astute participants in this thread);
Potential and current technologies (and issues) associated with data and position reporting.But hey, there's always hope, and some have posted great info on No. 2.

(and yes, I've read all the posts, but think it's time to stop on this one)

HarryMann

18th Jun 2009, 00:22

Re: Galley/kitchen unit

It may well have been robust enough to resist fragmentation while falling (free, on its own), but probably not strong enough to resist high speed air mass.But being light and very stiff (sandwich construction, sic!) it'd slow down very quickly perhaps without significant damage... drastically & rapidly reducing airloads to minor free-fall conditions i.e.. it would be blown backwards very fast negating air-load build-up from total Q

Alternatively, if happened to be at the open end of broken fuselage and sinking, buoyancy might well release it to the surface.

Dutch Bru

18th Jun 2009, 00:25

Great job with the pics. Perhaps you would like to add this one as well ?

http://www.eurocockpit.com/images/ACARS.php

Dutch Bru

18th Jun 2009, 01:12

Paint and it can be a lot worse:

Photos: Airbus A321-211 Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/Air-France/Airbus-A321-211/1301626/L/&sid=68ebd27dcfdc78454c60b7ba3c84d20b)

EGMA

18th Jun 2009, 01:19

Re the comments on weather radar. It shouldn't be forgotten that radar cannot see through cells.

It may be that AF avoided a cell only to find a massive cell hiding behind it.

Dutch Bru

18th Jun 2009, 01:27

http://img3.imageshack.us/img3/9615/090601met9irzoomanim.gif (http://img3.imageshack.us/my.php?image=090601met9irzoomanim.gif)

Interesting report also of severe turbulence encounter of Dragonair A330, albeit with a less dramatic ending:

http://www.cad.gov.hk/reports/main3.pdf

Phatesse

18th Jun 2009, 01:42

Nice animation.

Look carefully just under and to the left of letter "T" in "Tasel" around 2:30 UTC. Goes away at 3:00 UTC. Do you see it?

Will Fraser

18th Jun 2009, 01:46

30-40 degrees shaft..... warm??? Quite the up elevator?

barstow

18th Jun 2009, 01:55

"Nice animation.

Look carefully just under and to the left of letter "T" in "Tasel" around 2:30 UTC. Goes away at 3:00 UTC. Do you see it? "

Yep, it goes away at 3:00 UTC because that's when the loop of the GIF finishes...... :ugh:

Hyperveloce

18th Jun 2009, 02:29

yes, the Air Caraïbe safety report is a must read: it describes a similar sequence of fault reports and the loss of any protection (expt. load factor) in alternate law 2, without any possibility to revert to normal law. It also reports that some parts of the "unreliable speed" procedures are difficult to implement in real time, that GPS altitude & ground speed were used, that the icing of the Pitot probes goes hand in hand with an augmentation of the TAT (which then reflects the ice accretion), and several undue alarms.
The following EASA airworthiness directive is about the Quantas A330 which plunged due to a faulty ADR of the ADIRU1 which generated a NAV IR1 fault... and a nose down
http://www.securiteaerienne.com/ill/EASA_EAD_2009-0012-E_1.pdf
the failing ADIRU couldn't be switched off and prevented from contaminating the other (reliable) data. Isn't it strange that one faulty ADIRU (only faulty in its ADR part), even if it did not declared itself faulty, could bring down a plane whereas you had two other functional ADIRUs to cross-check data and detect outliers/unconsistant measures (AoA): I don't understand where is redundancy here ?
Anybody knows whether laser velocimetry (already used by Airbus on planes to study the turbulences in the wake of their airliners) is envisionned in the future to augment the anemometric chain ?
Time is running, hope the many people at sea will succeed into the recovery of the black box.
Jeff

PS) from eurocockpit (based on the A330 troubleshooting manual):
34 11 15 EFCS2 : PROBE-PITOT 1+2 / 2+3 / 1+3
triggered the real time warning (WRN) "F/CTL ALTN LAW"
27 93 34 EFCS1 : FCPC1 or FCPC2 with many subsequent possibilities(the message is truncated after EFCS2X
34 22 00 ISIS : should read here ISIS (22FN- 10FC) ALTITUDE FUNCTION or ISIS (22FN- 10FC) ATTITUDE FUNCTION or (22FN- 10FC) SPEED OR MACH FUNCTION. truncated message again
34 12 34 IR2 : ADIRU1 (1FP1) / ADIRU2 (1FP2) or bien ADIRU2 (1FP2) or ADIRU2 (1FP2) / ADR BUS 1 or ADIRU3 (1FP3) / ADIRU2 (1FP2). message truncated, no way to say which of the 4 subsystems is failing
22 83 34 AFS : this is about the FMGEC1 (1CA1) but message trucated after (1CA1), beyond the failure of FMGEC1 itself, the TSM suggests 38 failure modes.

quaeler

18th Jun 2009, 02:42

barstow-
Yep, it goes away at 3:00 UTC because that's when the loop of the GIF finishesThat's illogical: there's a frame at 3.00 UTC which contains data; the data it contains is [presumably] valid -- it doesn't matter whether it's the last or the first frame, it is presenting information for the state at the timestamp given.

ClippedCub

18th Jun 2009, 02:53

Paint and it can be a lot worse:

We can say they didn't encounter significant hail from the condition of 447's VS. We can also rule out a high energy impact with the water.

GreatBear

18th Jun 2009, 03:01

Been reading this thread since June 1. The blend of fact and speculation has been just about right for a situation where facts are scarce, the unknowns are plenty, and the need-to-know is high. I'm sure that all you drivers get pretty focused, now, when cosying toward the coffin corner at FL370 and mach .8, asking yourself "what if" questions and wondering if you will be unexpectedly flying "tight ass," the way Google translated a French captain's comment earlier in this thread, describing his sudden high-altitude Direct Law flying experience, before the post was edited to read "seat-of-the-pants."

For those following this thread (over a thousand visitors at this very moment) who are interested in the needle-in-the-haystack problem (locating and raising the FDR and CVR from the deeps of the Atlantic Ocean), you should know that mounting such a subsea salvage operation is a HUGE undertaking requiring incredibly specialised gear, support vessels, large crews, scientific expertise, and lots of money. The NTSB and the FBI spent USD31.4 million on TWA Flight 800 (TWA Flight 800 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/TWA_800) and Air France Crash Update ? Deep-Sea Robots Could Recover Air France's Black Box - Popular Mechanics (http://www.popularmechanics.com/science/robotics/4320244.html)). BEA head Paul-Louis Arslanian is not optimistic.

Task: Find the aft section of the A/C. Assuming the FDR and CVR were not ejected, that's where the pinger(s) are mounted.

http://www.timestream.com/af447/searchArea.jpg

By June 16th, the Brasilian team seems to have narrowed the visual search area (area de busca visual) to a 19,000 sq. km swatch westward of TASIL (see above or link to original at http://www.fab.mil.br/portal/voo447/INFOGRAFICOS/160609/coletiva_160609.ppt). As RuddA pointed out earlier in this thread (#1374), backplotting ocean current drift and wind effect on debris is tricky, so acoustic trawling for the pinger may actually be going on in a swath as far as 200km eastward of the search for debris and remains. I have been a USCG licensed Merchant Marine Officer (Master) and also a Private Pilot for the last 30 years, mostly navigating in 2-dimensional space, and I can tell you that even with the most up-to-date current charts, weather reports, and the best local knowledge (not much of that mid-ocean), it's still a reverse-dead-reckoning set-and-drift calculation with sometimes unknown margins of error. Sort of like using a bubble sextant or wind triangle to update your ground vector every 300km based on TAS and heading, but in reverse (those Navigators have gone to the same place as the cockpit Flight Engineers). I'm sure the Brazilian/French team has spent hundreds, more likely thousands, of navigator man-hours best-guessing the "Ultimo Reporte" location and the debris drift.

It's pretty deep. Thousands of fathoms deep. And the terrain, near the Mid-Atlantic Rift (MAR), can be steeply mountainous (escarpment "slopes of at least 30o, with slopes up to 50o being common and maximum slopes reaching more than 60o" (Mid-Atlantic Ridge 29oN: New Insights on Ridge-Axis Faulting From High-Resolutio (http://adsabs.harvard.edu/abs/2003AGUFM.T12D0496S))). Dutch tugs chartered by the French Accident Investigation Authority (FAIRMOUNT EXPEDITION and FAIRMOUNT GLACIER - (Fairmount Marine B.V. (http://www.fairmount.nl/news.php?idObject=681))) are towing U.S. Navy listening sensors. The French nuclear sub, EMERAUDE (http://images.tvnz.co.nz/tvnz_images/news2009/technology-communication/submarine_2.jpg) is searching and listening. Pinger batteries may be dead in another two weeks, they say.

Without the pinger(s) it gets harder, but perhaps not impossible, to locate the wreckage. Towed Ocean Bottom Instrument (TOBI - TOBI (http://www.marine.gov.uk/tobi.htm)) might be able to resolve the wreckage from the sea floor topography after the pingers quit. 30kHz sidescan sonar with swath bathymetry capability, chirp sub-bottom profiler, three-axis high resolution magnetometer and an across track resolution of 2 meters could image a fuselage or wing(s) - A330 wingspan is 60.3 m (197 ft 10 in). For more on using this technology, see Searle, R. C. (Mid-Atlantic Ridge 29oN: New Insights on Ridge-Axis Faulting From High-Resolutio (http://adsabs.harvard.edu/abs/2003AGUFM.T12D0496S)) and D. K. Smith (Viewing the Morphology of the Mid-Atlantic Ridge From a New Perspective (http://www.agu.org/sci_soc/eosdksmith.html)). A decade ago Smith mapped the seafloor along the MAR some 25 degrees northward from TASIL:

http://www.timestream.com/af447/smithSeafloor.gif

Task: Recovery

Two French deep-dive manned submarines, 8m-long NAUTILE (Nautile (http://www.ifremer.fr/fleet/systemes_sm/engins/nautile.htm)) and its sister, the VICTOR 6000, and their support vessel (the POURQUOI PAS) are standing by (Business Report - French submarine has all the right credentials to lead search operation (http://www.busrep.co.za/index.php?fSectionId=2515&fArticleId=5023144)), ready to recover the FDR and CVR. NAUTILE worked the TITANIC wreck with two retractable manipulation arms and a sampling basket.

http://www.timestream.com/af447/nautile.jpg

This is a non-speculative status report dealing with the big picture and, I hope, with helpful links to detailed references. With respect to BreezyDC (#1886), I'd like to believe that in this particular case professional pilots are, indeed, interested in more than ACARS message sequencing, TCAS, FBW, weather radar, joysticks, and SOPs, as important as these discussions are. As SLF for more than a million miles, I'd rather fly with somebody in the left seat who has looked at *all* the material presented in this thread and taken reflective time to "noodle" through the many "what-ifs" -- someone with an agile mind (quick and always curious). Already, there are lessons learned and new AB-type pitots are (being) installed.

On the other hand, BreezyDC, you are probably right: perhaps time to restart this almost 100-page thread in a couple of new directions... Aside from progress reports or a "Found It!" announcement, might have to wait until the official required prelim report end of the month, and maybe not much will emerge, even then.

Let's hope that the batteries last, that the FDR and CVR haven't imploded, that the wreckage isn't jammed tail-first into a subsea ravine, and that the BEA has deep pockets. At this very instant, thousands of people are on the ground and on the water helping to better understand what the ACARS told us, what the debris and remains tell us -- and why. We are but two weeks into a catastrophic event that, for some, will never end.

ClippedCub

18th Jun 2009, 03:19

A classical spin entry into the water could explain a lot if the debris dispersion can be explained by wind and currents. Reviewing the 3-view, the rudder would be blanketed by the horizontal and with the wing sweep it would wind up pretty tight. The pitots wouldn't agree due to yaw rate and the rudder would be left in limited travel. Would be a tough recovery if it was even possible with the rudder limit. Would require a fluke (500 year?) warm air column with a sideslip at the stall break tough.

Will Fraser

18th Jun 2009, 04:44

One possibility without knowing the 'last permitted' deflection is how little rudder deflection is needed to overstress the VS at high mach. Without much in the way of instruments, what's left? Feel. A yaw is uncomfortable and telegraphs its stress in the seat cushion. The 330 is no different. That the Rudder was limited to 6 or 8 degrees doesn't prevent severe stress from impacting the tail. If there was coupling that followed an oscillation, that would be bad. There is not nearly enough of a sequential trail to establish much. A question I would have is how far into and up to the a/p disconnect limits did the a/c proceed? Was it one limit that nudged the trip out? A combination? The most important data is the amount of activity in each of the three axes were the pilots left with at disconnect? Not only that, but how much authority is too much for limited/degraded flight cues from the panel? Boxes.

PJ2

18th Jun 2009, 07:06

GreatBear;
Fabulous post, thank you.

PTH:
DC ATE and CAPT AIRCLUES
You two are the only people on this thread worth reading.Ouch!...:ouch:

and given a choice between descending and getting my pitot tubes back and using more fuel or NOT getting my pitot tubes back and dying...what is wrong with this question.

I haven't left North America in my flying. But I have had to fly below the Flight Levels in jet transports for various reasons...the fuel penalty isn't that great...it is doable,manageable etc.
In setting aside the fuel penalty for flight at substantially lower altitudes with turbine-powered aircraft, which engine-type are you referring to, the PW1's or the high-bypass PWs or Trents? I don't know what the fuel flows are for the smaller engines but I think the differences would be among the factors affecting the decision-making process to descend. A descent to say, 10,000ft for "warmer" air could increase the burn such that one is burning into all contingency fuels and possibly the MFOB. It's a very big decision. Of course, (as DC-ATE points out), diversion fuel should be in the plan, and of course it is - in this case, a diversion, say, to Recife, in a serious emergency, would be a possible choice. Of course, we do not know what this crew faced.

That isn't to say a descent to clear ice buildup is unwise or questionable - the captain must do what s/he must do to ensure safety and survival, but as you would know, the decision is not a simple nor a straightforward one.

I tend to think that in the emergent circumstances faced by the AF cockpit crew, the time and therefore the availability of such a decision was perhaps not there. What do you think?
GEE GUYS (not dc8 and clues) ...what happens if you lose pressurization...and have to fly at 10,000feet!
Planning for these kinds of contingencies by overseas long-haul carriers is a matter of routine policy including pressurization loss and engine-out descents. - quick example, YVR - HNL, a plan involving a diversion at 10,000ft with engine ice ON would use SEA, PDX or SFO then HIL/OGG depending upon winds/temps.

Diversion routes from anywhere along the flight-planned route as well as at either the equal time points or equal fuel points are analyzed for potential icing at 10,000ft. Where indicated, fuel is added to handle the additional burn. In these cases, the emergency plan is to arrive at the diversion airport having burnt into the MFOB.

ClippedCub;
A classical spin entry into the water could explain a lot if the debris dispersion can be explained by wind and currents. Reviewing the 3-view, the rudder would be blanketed by the horizontal and with the wing sweep it would wind up pretty tight. The pitots wouldn't agree due to yaw rate and the rudder would be left in limited travel. Would be a tough recovery if it was even possible with the rudder limit. Would require a fluke (500 year?) warm air column with a sideslip at the stall break tough.
The notion that AF447 possibly entered a "flat spin" has been broached a few times.

I am not an engineer nor a mathematician so my question is informed by a bit of reading...always a dangerous thing! Please bear with me as I had never asked the question as to whether a transport category aircraft could "flat" spin:

Given some distance between the two points round which any aircraft, but in this case a jet transport, would be theoretically rotating in a spin, namely the forward point or center of gravity, (weight?) and the aft point, center of lift and given a normal CofG position (about 4k kg of fuel would be in the tail at that point), and intact vertical and horizontal stabilizers, could these two points produce a flat spin under specific circumstances?

I have always perhaps laboured under the understanding that a transport category aircraft in a fully-developed stall would produce a substantial nose-down pitch attitude, possibly with spiral characteristics if roll angles were high and which would take an enormous amount of sky from which to recover.

I realize that any mass can "spin" and any aircraft with a narrow CofG, CofLift relationship could be made to flat-spin, but the development of same given usual characteristics of a high-altitude full stall do not seem to me to be conducive to the development of a flat spin.

There is precious little in the literature. D.P.Davies covers it but there is no discussion about "flat" spins, just the spiral dive stability and of course the various stall conditions including the "super-stall".

The question is "out there" and has been asked, so I think it is important to understand the nature of the stall, the spiral dive and the propensity to spin (or not) of this kind of airframe/airfoil.

If the mods deem this "Tech Forum" stuff, so be it - see you there. I think however it is "in context".

Many thanks,
PJ2

captainflame

18th Jun 2009, 07:37

Greatbear:

I'm sure the Brazilian/French team has spent hundreds, more likely thousands, of navigator man-hours best-guessing the "Ultimo Reporte" location and the debris drift.

:= they did not "best guess" the "Ultimo reporte"

This is the last VHF transmission of reporting point by the crew before leaving the Brazilian controllers. It is established that this report was made at 01:33 estimating TASIL at 02:23.

Though I agree, the search was initially launched by applying current/wind drift patterns.

Source: early BEA briefing on french TV

captainflame

18th Jun 2009, 09:17

Torque...:

- Most newspapers are today saying that the plane broke up in mid air. How is this possible? I always thought that airplanes could withstand all kind of punishements even fly inside the meanest cells (after all C130's do fly inside hurricanes) without breaking apart.
- Why did the crew decide to proceed inside a cell/storm that by looking at Tim Vasquez analysis for example, looked like a monster?

- There is ABSOLUTELY NO EVIDENCE that the plane broke up in the air. Media are picking up info, among other sources, on forums like this one !!!... where all kinds of pros and not so pros make comments, speculate, emit possibilities, pretend they are experts etc...

It is majorly BOGUS !!

C130 and other hurricane chaser airplanes are structurally MODIFIED to withstand extreme turbulence stresses. That's why they can fly inthere !

A civil airplane is not so modified and possibly could exceed its structural limits under certain circumstances, which are linked to LOSS OF CONTROL in flight.
An Airbus has Load factor protection in normal flight, and only looses this protection when Flight controls systems are severely degraded.
Load factor will however not protect them from other structural exceedance such as flying too fast (ie the never exceed speed)

Without going into too many details here....of course.

- There is absolutely NO EVIDENCE that the crew flew into a cell.
- There is absolutely NO EVIDENCE that there was any monster cell (typhoon type)
Even Tim Vasquez is being careful with his model.

Weather analysts report that the Convective weather pattern that night in that area did not present anything out of the ordinary, everyday equatorial storm system.

I'm French....can you tell ?:ok:

Wader2

18th Jun 2009, 09:34

Found an interesting discussion in the Tech Log forum on spin recovery in a 737 - theoretical I hasten to add - but spooky as the message is dated 20 May!

http://www.pprune.org/archive/index.php/t-374623.html

Finn47

18th Jun 2009, 09:51

Since the BEA press release from yesterday says

The last position message from the airplane was broadcast by the ACARS automatic system at 2 h 10 UTC.and this most likely means exact coordinates, why would anybody have to "second guess" the location of an "ultimate report"?

BOAC

18th Jun 2009, 12:26

Quote:
The last position message from the airplane was broadcast by the ACARS automatic system at 2 h 10 UTC. - any link to the 'press release', preferably in English? What do we have here? Runaway journalistic mis-interpretation of a statement? A previously unreleased ACARS message or part of? Just a spoof - or have I simply missed this pos report? If so, apologies - there's a lot of static here.

If true, and we ASSUME things went badly wrong at 0214Z, we have a circle of only 4 mins or so of flight to fix the initial crash site.

GreatBear

18th Jun 2009, 12:47

OK, captainflame and Finn47, "best-guessing" (not second-guessing) the seabed location of the AF447 hull is a PROCESS based on probabilities and a pot full of known and inferred datapoints. Debris locations and "Ultimo Reporte" are datapoints in that pot... Perhaps I should have said "best-guessing from the known and estimated flight path of the A/C and the location of found debris;" all are datapoints. Sorry for the confusion. Likely at play here is Bayesian search theory.

The most interesting search in similar circumstance to AF447 was conducted in 1968, for the nuclear submarine USS SCORPION, where Dr. John Craven, the Chief Scientist of the U.S. Navy’s Special Projects Division, successfully used Bayes’ Theorem of subjective probability to ultimately locate the wreck far from where many thought it should be found. The pot of data available in the AF447 case is eerily familiar:

"On May 27, 1968 USS SCORPION was reported missing with ninety-nine men on board. Nobody had any idea where SCORPION was or what had happened to her. All they knew was that the 3,500 ton nuclear attack submarine was due back in Norfolk, VA and had failed to arrive... The site of the first explosion – codenamed Point Oscar - marked where the search would begin. The water at Point Oscar was 2 miles deep. The SCORPION would have stopped imploding about 7,000 feet before she hit bottom, cutting off the acoustic trail. Depending on how fast she had been traveling, and in what direction, and depending on the force of the implosion and the position of her stern planes as she fell, she could have been thrown miles further... [Craven] asked a group of submarine and salvage experts to bet on the probability of each of the different scenarios being considered to explain SCORPION's loss. Once the bets were completed Craven sat down to draw a probability map... Years later mathematicians would write a book based on their work with Craven entitled "Theory of Optimal Search," the U.S. Coast Guard would adopt the method for search and rescue, and the Navy would use Craven’s interpretation of Bayes’ Theorem to locate sunken ordnance in the Suez Canal." (A good read at http://en.wikipedia.org/wiki/USS_Scorpion_(SSN-589) (http://en.wikipedia.org/wiki/USS_Scorpion_%28SSN-589%29))

This PPRuNe thread has been helpful, I should think, in providing expert data points and scenarios. As I said in my last post, likely thousands of expert hours have been invested in answering the best-place-to-search question. Certainly a lot of assets have been deployed to search "somewhere."

"Bayesian search theory is the application of Bayesian statistics to the search for lost objects. It has been used several times to find lost sea vessels, for example the USS SCORPION. The usual procedure is as follows:

1. Formulate a number of hypotheses about what happened to the vessel.

2. Corresponding to each hypothesis construct a probability distribution for the location of the vessel.

3. Construct a probability distribution for actually finding an object in location X if it really is in location X. In an ocean search, this is usually a function of water depth — in shallow water your chances of finding an object are good if you are looking in the right place. In deep water your chances are reduced.

4. Combine the above information coherently to produce an overall probability distribution. (Usually this simply means multiplying the two distributions together.) This gives the probability of finding the vessel by looking in location X, for all possible locations X. (This is like a contour map of probability.)

5. Construct a search path which starts at the point of highest probability and 'scans' over high probability areas, then intermediate probabilities, then the low probability areas.

6. Revise all the probabilities continuously as you search, i.e. if you have searched location X then the probability that the vessel is there is greatly reduced (though not usually zero) and the probabilities of all other locations must be increased. The revision process is done using Bayes' theorem."

Bayesian search theory - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Bayesian_search_theory)

OleOle

18th Jun 2009, 12:56

Press release 12 June 2009
Flight AF 447 on 01 june 2009
A330-200, registered F-GZCP
During the third Press Conference that was held on 17 June on the progress of the investigation into the accident to flight AF 447, the BEA presented the sea search operations (http://www.bea-fr.org/anglaise/actualite/af447/sea.search.ops.pdf) that are under way. It contains a map of the locations of the airplane debris, including the fin, that were recovered from the surface of the sea. This debris field corresponds to a relatively small area with a drift towards the north.
A targeted undersea search area has been established based on the position of the parts recovered – more than four hundred items have been referenced – and on the flight path of the airplane reconstituted from data transmitted by the ACARS. Exploration began on Wednesday 11 June with an increase in the means deployed until 16 June 2009.
During this press conference, the few validated facts available at this time were set out and detailed:
The airplane was in cruise at flight level 350 (about 10,500 metres).
No messages indicating problems were received on the air traffic control radio frequencies.
Close to the planned route of the airplane above the Atlantic there were significant convective cells characteristic of the equatorial regions;
The last position message from the airplane was broadcast by the ACARS automatic system at 2 h 10 UTC.
Between 2 h 10 and 2 h 14 UTC, 24 maintenance messages were transmitted by the ACARS, including 14 between 2 h 10 and 2 h 11.
Analysis of these messages shows inconsistencies between the various speeds measured. Most of the messages appear to result from these inconsistencies; they correspond to the loss of several flight assistance systems.
49 bodies were recovered between 6 and 11 June 2009.[/From News (http://www.bea-fr.org/anglaise/actualite/actu.htm)

4 min at 450 knots gives a radius of 30 nm.

It does not really fit to the difficulties of finding any debris in the first days of the search.

ClippedCub

18th Jun 2009, 12:58

C130 and other hurricane chaser airplanes are structurally MODIFIED

Negative. They are off the shelf. The only mods are for equipment.

ClippedCub

18th Jun 2009, 13:19

I realize that any mass can "spin" and any aircraft with a narrow CofG, CofLift relationship could be made to flat-spin, but the development of same given usual characteristics of a high-altitude full stall do not seem to me to be conducive to the development of a flat spin.

Wasn't referrig to a flat spin, a regular nose low spin would explain a lot.

Spins occur when one wing is stalled and the other is unstalled. The Bucker Jungmiester and Jungman are legendary for snap roll and spin performance and the primary reason is because both upper and lower wings are swept 11 degrees or so. Pull into a stall, yaw, increasing sweep on one side and decreasing sweep on the other. The outer unswept wing produces more lift because it is now unswept and traveling faster. The inner wing is now effectively swept 20 degrees and is moving through the air slower than the outside wing.

Visualize this same dynamic starting with 25, 35 or even 45 degrees of wing sweep. It would be almost like effectively losing the entire wing on one side. The aircraft would spin like a top.

Once entered, since the engines are underslung, power would tend to flatten the spin out. Would imagine the engines being slung off in short order, since the spin would be violent once it was well developed. Would take a turn or two to really wind up and stabilize. Then the cg would travel aft which could promote flattening.

The assertion wasn't whether it was flat or not, either type of spin could explain a lot, long as it were upright.

DC-ATE

18th Jun 2009, 13:27

re. Post # 1873, P.94 -
by - EGMA -
Re the comments on weather radar. It shouldn't be forgotten that radar cannot see through cells.
It may be that AF avoided a cell only to find a massive cell hiding behind it.

WHAT is going on here?! Someone posted a very good explaination of aircraft radar in response to the above post. Because of that, I did not respond to save an 'extra' post being displayed. There were NO bad remarks or speculation in that response. It was deleted either by mistake or intentionally. Wish I would've saved it along with the persons name. Anyway.....my response was going to be something like:

I do not know what weather radar systems are in use today in 'modern' aircraft, but we had C-Band radar that COULD "see" through storm cells with NO problem, thereby enabling one to navigate through and around storms.....IF one chose to fly that way. I personally used the weather radar for its intended purpose. And that was to AVOID the weather, not find your way through it.

We do NOT know what the situation was with AF447 and their use of their weather radar at this time, and perhaps will never know. While it appears as though they were too close to the 'bad' weather, we really do not know.

I do not understand why someone is allowed to make a remark on here that is false and have their post remain only to have the rebuttal post deleted.:confused:

Graybeard

18th Jun 2009, 13:37

Thanks, DC-ATE. I re-posted it over at Tech, where it has already passed the good censor.

UAL used to say the other airlines avoided storms, while they co-existed with them. You may have got a rougher ride on UAL, but they always made it.

UAL was known for exceptionally good WXR training, whereas it was sadly lacking nearly everywhere else in the US. Astute airlines sent their pilots to UAL for Wx training.

GB

Not_a_pilot

18th Jun 2009, 14:21

From the June 17, 2008 BEA press release (http://www.bea-fr.org/anglaise/actualite/af447/pressrelease20090617.html) quoted above by OleOle, there is a link to this .pdf (http://www.bea-fr.org/anglaise/actualite/af447/sea.search.ops.pdf) that answers lots of the questions asked repeatedly about the investigation, including:
ships deployed
data exchange between French and Brazilian authorities
day-by-day maps of the locations of debris and corpses found
undersea map of area
how the beacons on the FDR and CVRs work including a sample of the sound
how the undersea searches are organized

Squawk_ident

18th Jun 2009, 14:35

There are very few people that will be allowed to speak through any media.
Almost only two:
Gérard Feldzer is one of them. Former Airbus pilot and instructor on Air France. He is retired and is now the Director of the Musée de L'Air et de l'Espace at le Bourget (very nice museum by the way).

François Grangier is the second one. Presented in all the Media as an Airline pilot and aviation accident expert at the BEA. It is almost impossible to know more about FG and particularly what airline employs him. Last time I saw him on TV he said he was just coming back from HKG but no journalist would be impolite enough to ask him on which airline. On some French forum there are (sarcastic) members saying that FG was driving the FGZCP when, while taxiing, it unfortunately cut an A320 horizontal stabilizer. I would therefore tend to think that FG is an AF pilot that is detached to the BEA if needed. Grangier has his own site that you can easily find.
These two persons are allowed to speak about airline crash and especially when it happens to a French airplane.
Because things are going fast and these two can't be everywhere, we can see others members speaking of the accident aircraft on various media. Always AF pilots and always members of the SNPL (syndicat National des Pilotes de Ligne) Union. All these AF employees can speak freely and say what they want about a disaster involving a (their) company aircraft.
FG at the end of a recent French TV talkshow on the 2nd of June ("C dans l'air" on France5 ) said something astonishing but very revealing of his state of mine. At the end of the emission some selected questions from the audience are sent by SMS. One question was about the ability of the submarine's sonar to get an echo from the bottom of the sea. FG sharply answered "Dead bodies doesn't make noise."
Unfortunately the broadcasting is not available in its integrality now. But you can see the latest one here (with GF of course, see below please).
My personnal feeling and I'm very sorry to say that, is that some people within official bodies in France are praying that these boxes shall never be found.

The "C dans l'air" talkshow of the 16th of June was titled : AF447 corpses are "speaking" (still watchable in its integrality but not for long I'm fraid because it's reduced after a while)

C dans l'air - France 5 (http://www.france5.fr/c-dans-l-air/index-fr.php?page=resume&id_rubrique=1183&date=2009-06-16)

Well only the fact that bodies were found 80km apart was discussed but nothing else interesting and, rather amazingly no doctors expert in autopsy were present. At the very last seconds of the talkshow there's a SMS question : Is the BEA independant from manufacturers, economic pressure or Grandes Ecoles? Answer by GF ( not FG this time...): No.....the BEA is (people starting to smile) influenced by nobody...heu yes it's the contrary, it's independant. Phew!

About the BEA. Some months ago their internet address was Bienvenue sur le site du Bureau d'Enquêtes et d'Analyses (http://www.bea-fr.org/) (yes .org !)to underline their total and absolute independancy from any States, Authorities and lobbies whatsoever.
This address/URL has changed (redirected) but if you still type it like this (or follow the link) you will reach the site. For how long? The BEA is depending of course of the Civil Aviation General Direction (DGAC) subsidiary of the French Ministry of Transport. We do not know the exact constitution of the investigation team. Who they are is a mistery. BEA is not the NTSB. Nothing on its site about that. Is there any member(s) of Airbus and/or AF, the answer is yes or very likely no, but normal ordinary French citizen still don't know about that. But the BEA is independant. Like in any modern western countries.
BEA has announced that it will try to publish a report before the end of June. It simply forget to mention that it is ICAO mandatory to publish an "intermediary" one within one month of an aviation accident.
What we know is that Paul-Louis Arslanian is the Chairman of the BEA. There was a press conference yesterday hold at the BEA office at Le Bourget. Nothing special happens except that BEA is saying that they know nothing about the bodies recovered. It can't be serious because we read these informations via the internet from Brazilian side. PLA is very displeased because the Brazilian medical team has forbidden to a BEA expert to enter their forensic laboratory at Recife. There are already 3 French experts in the place who are working with the Brazilian specialists but the BEA wanted their one to participate.

PLA became nervous near the end of this recording:
YouTube - Conf de presse du Bea sur AF447 news BFM 170609 (http://www.youtube.com/watch?v=HuP_Z99vqVE)

When a Brazilian journalist asked a question (+5mn47sec). We can hardly hear the question (in French) of the journalist but PLA said that he doesn't speak Brazilian (this journalist spoke a perfect French) and somehow abruptly give the parole to another journalist. This new journalist (female) questionned PLA on something ( I could not understand because journalists did not have a microphone) and he became irritated again.
At +2'34'' he said something about bodies "Tous les corps qui sont ou seront trouvés seront récupérés."
"all bodies that are found or will be found will be recovered" We can then hear some people starting to laugh.
Later on (+5'00) he said that "May be we are effectively approaching a little bit more of the goal" : "on se rapproche peut-être effectivement un peu du but" (with a restrained smile).

About the forensic specialists :
Le Figaro - Flash actu : AF 447: couac entre le Brésil et le BEA (http://www.lefigaro.fr/flash-actu/2009/06/17/01011-20090617FILWWW00615-af-447-couac-entre-le-bresil-et-le-bea.php)

sorry everything is in French but at least for the newspapers there are easy way to translate.

Herbie K

18th Jun 2009, 15:11

One post from me here and one only

A request

Many of us come here to read, learn and see what is happening in the aviation business. Its very interesting and not locked away as a private forum.

So PLEASE, would all the armchair pilots and those asking questions that break up the threads, please stop posting. Its pretty obvious that those users in the know (real pilots and technicians) are gradually working through a process of elimination and while it might not be used directly in the investigation, you can bet that there are people browsing the site in order to either jog their memory or examine other avenues that are mentioned.

Google is there, if you want to find out how systems work, google it, but please don't wear down the patience of the pilots, we don't want them to stop posting, the topics go stale or the board become exclusive.

Thank you for your time and the professionals for having us non-flyers here!

ps. Congrats to ES on his latest appointment.

lomapaseo

18th Jun 2009, 15:17

Does anybody have a photo of what this looks like undamaged in situ?

Airliners met etc.

The damage at the bottom has attracted my interest

http://www.fab.mil.br/portal/voo447/FOTOS/070609/foto_2.JPG

Carjockey

18th Jun 2009, 15:25

From 'The Times'

Airbus computer bug is main suspect in crash of Flight 447 - Times Online (http://www.timesonline.co.uk/tol/news/world/us_and_americas/article6523467.ece?Submitted=true)

Way back in this thread (or was it in the locked thread?) I expressed my opinion that more was known about the cause of this accident than was being said publicly.

Any comments?

Me Myself

18th Jun 2009, 15:50

Nothing new really. It's been suspected from the very begining.
let's suppose for one second they went through the same incident Qantas did in the kind of weather they were flying. You're toast.
The fact that AF shows full confidence in the Airbus is quite understandable.
Imagine what trough we'd be in if the fleet was grounded. That would be the death of us.

PJ2

18th Jun 2009, 16:00

lomapaseo;

I think this photo of the crew rest module shown below of a Lufthansa A340 module is what you're looking for?

http://i277.photobucket.com/albums/kk76/batcave777/Crewrestmodule.jpg

GHOTI

18th Jun 2009, 16:00

DC-10 fleet was grounded on less evidence than we have so far on the A-330. L-188s kept flying despite two in-flight shreddings because a California-based airline had only Electras in their fleet. Economics dictate safety policies.

ACLS65

18th Jun 2009, 16:11

carjockey: I thought the Times chose a rather sensationalist headline by referring to the "main suspect" as a "computer bug". While some hardware or software bug has not been ruled out, what the article text really talks about is the possibility the flight control system was receiving erroneous information from the sensors rather than a computer bug per se. As someone mentioned many msgs ago GIGO, garbage in, garbage out. It is quite possible that had a human computer been given the same information and situation that AF447 faced he/she may not have reacted any better.

lomapaseo

18th Jun 2009, 17:08

Thanks to all for confirming the photo that I posted was of a crew rest area in the cargo hold. It probably was discussed earlier with a link to the photo but I missed the link before it got deleted.

I suspect that the cargo area was opened before it hit the water and other bins were probably part of the debris field. Do we recognize other bin pieces in the other photos?

swish266

18th Jun 2009, 17:38

My personnal feeling and I'm very sorry to say that, is that some people within official bodies in France are praying that these boxes shall never be found.
Squawk ident : spot on!
A lot of fishy things coming up with the bodies and debris.
As I said on 2nd June
On CMC and ACARS
This system can be very customized. AF knows much more than they admit. They have been talking to their legal team right from the start. They will spoon-feed us the info when they are told its ok by their lawyers.

AF knows much more than they want it to appear to...
I would love the moderators to migrate the technical side of this discussion to Tech Log and leave this forum to not so technical speculation and rumors regarding this disaster...
I personally believe there was nothing wrong with the plane until it entered the severe weather. How and why it entered? To me the operational side presents much more opportunities for discussion...
We, professionals need to understand how come this exactly flight got to prove the 10000000 millionth probability in the statistics exercise...
:confused:
:confused:
:mad:

aguadalte

18th Jun 2009, 17:39

ISIS, stby altitude, altitude indications
As written (by me among others) in previous posts, the ISIS is a self contained instrument providing Airspeed from stby pitot, attitude from internal gyros, Altitude from STBY static ports, and slip/skid info from accelerometers,

ISIS IS the stby instuments ! http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/thumbs.gif

direct inputs from the pitot and from the static ports are provided. No computer inbetween !!

Also, the FMGC provides a "backup altitude" which is provided from the GPS's on the DATA / GPS page. It's not a pressure altitude, but nevertheless gives a good idea of whether you are at 35000' or 2000' !!

The QRH checklist for "Unreliable airspeed" suggests to use this it by the way.
Just a word to clarify that ISIS doesn't receive "attitude from internal gyros", it receives inputs from ADIRU1 and 3. It also receives inputs from Stand-By Pitot and Stand-By Static Probes.

If this aircraft was equipped with ISIS, it was surely also equipped with Back-Up Speed Scale and Back-Up Altitude, that displays on PFD's and gets information from AoA probes and GPS, respectively.

This is very important, once Back-Up Speed Scale and Altitude are only displayed when ALL ADR's are switched OFF. The old procedure (for the stand-by horizon equipped aircraft), would call for the trouble-shooting of the IR fault, and in case of all confirmed to be faulted, one would be advised to switch off those connected to Captn PFD and FO PFD, i.e., IR1 and 2. This would allow the aircraft to revert to Alternate Law.

This system (although brilliantly designed) seams to work fine in rather smooth air and on flight simulators, but I find it very difficult to see it properly working in a heavy turbulent environment, as seemed to be the case of AF447.

BOAC

18th Jun 2009, 18:02

Just a word to clarify that ISIS doesn't receive "attitude from internal gyros", it receives inputs from ADIRU1 and 3. It also receives inputs from Stand-By Pitot and Stand-By Static Probes. - I have been asking this for a while with no definitive answer - are you DEFINITE there is no laser gyro unit in ISIS? Others seem to think there is, and that the ADIRU inputs are pressure values only. SOMEONE in the Airbus world must know, surely? No wonder people are confused!

captainflame

18th Jun 2009, 18:46

ClippedCub:

I stand corrected !
Was thinking of other types used I guess. From memory, off one of these Disc. Cha. or Nat. Geo. footage...
Yeah I know, not quite first hand !

captainflame

18th Jun 2009, 19:17

aguadalte:

Just a word to clarify that ISIS doesn't receive "attitude from internal gyros", it receives inputs from ADIRU1 and 3.
:=

The problem, as said earlier, is that ISIS containts are classified. I know it sounds weird but again, no one opens up this box !!

While it is true that it gets inputs from ADIRU 1 and 3, it is also true that it contains gyros !!
What inputs from ADIRUs ? I have no idea because the Airbus doumentation does not describe this. It could be to compare data, or to receive inputs from AOA and such....

It also is linked to ILS receiver 1 for example as you can display the LOC/GS sacles and diamonds.

As a matter of fact, ISIS needs to "align" its ATTitude on power up, and has an in flight ATT re-initialization button as well.

So the GYRO, Attitude information IS definitely self contained !

It is a BACKUP instrument. We know how to use it, we know what can go wrong with it, we do not know how it works inside !
Do we really need to ? not so sure.

By the way it is powered by BOTH the DC ESS bus and Hot Bus 1

PJ2

18th Jun 2009, 19:25

BOAC;
I have been asking this for a while with no definitive answer - are you DEFINITE there is no l@ser gyro unit in ISIS? Others seem to think there is, and that the ADIRU inputs are pressure values only. SOMEONE in the Airbus world must know, surely? No wonder people are confused!

The ISIS is powered off the DC ESS bus with an auto-backup to Hot Battery bus 1.

While one can guess, I do not know what is meant by the terms, "accelerometer" and "gyrometer" in the "ISIS" box. The key in that understanding is, of course, whether or not if ADIRS 1 & 3 fail, does the standby horizon fail?

http://i277.photobucket.com/albums/kk76/batcave777/A330_ISIS_architecture_2009-06-1-1.png

Niveau390

18th Jun 2009, 19:30

Could it be that the data exchange with ADIRUs is only for comparison? Otherwise I am not sure why the ISIS box would contain its own gyro/accelero if not to provide independent information.

DorianB

18th Jun 2009, 19:47

Quote from the BEA website regarding these images:

"During the third Press Conference that was held on 17 June on the progress of the investigation into the accident to flight AF 447, the BEA presented the sea search operations that are under way. It contains a map of the locations of the airplane debris, including the fin, that were recovered from the surface of the sea. This debris field corresponds to a relatively small area with a drift towards the north."

June 10

http://i635.photobucket.com/albums/uu79/DorianBanks/th_June10.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=June10.jpg)

June 9

http://i635.photobucket.com/albums/uu79/DorianBanks/th_June9.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=June9.jpg)

June 8

http://i635.photobucket.com/albums/uu79/DorianBanks/th_June8.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=June8.jpg)

June 7

http://i635.photobucket.com/albums/uu79/DorianBanks/th_June7.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=June7.jpg)

June 6

http://i635.photobucket.com/albums/uu79/DorianBanks/th_June6.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=June6.jpg)

June 6-10

http://i635.photobucket.com/albums/uu79/DorianBanks/th_June6-10.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=June6-10.jpg)

PJ2

18th Jun 2009, 19:49

lomapaseo;
I suspect that the cargo area was opened before it hit the water and other bins were probably part of the debris field. Do we recognize other bin pieces in the other photos?
With one exception, I don't recognize other bin pieces but in the collection of parts on display there is/are:

- One exception re "bin" - what is probably a section of the F/A crew module marked "FWD"; I suspect it comes from the forward, left-hand side.

- Several overhead bin covers

- a longish, narrow section with two "porthole-ish" holes at the ends - I suspect this is part of a cabin bulkhead structure (from which the curtains hang, etc, likely between J-class and Y)

- the structure with the video screen is one of the bulkheads in Y-class which either divides the Y cabin or is part of the J-class/Y-class divider.

- the flourescent box is either the doctor's kit or the defibrilator. I note that it is essentially unscathed and still closed, (not broken open in the accident sequence). This kit was kept near the front of the aircraft but we do not know the location of this kit on the AF330's.

- there are a great many other smaller parts, all of which seem to be the same honeycomb structure - no surprise, as such structures float...

From the available information (photos), these large, intact parts exhibit fracture, tear or blunt force patterns (including being struck by other parts as described earlier) but not large deformation patterns or a shattering into small fragments normally seen in a high-speed impact with water.

What the rest of the structure may exhibit is not yet known.

The information supplied by Great Bear is encouraging in the sense that loss of the CVR/DFDR signals may not end prospects for recovery. This still recognizes the significant task at hand and when/if discovered, the difficulties in recovery.

BTW, the galley, which photos showed up on the 17th with the skin-diver, was actually found on the 7th, as indicated by this PPRuNe posting:

Galley photo June 07 (http://www.pprune.org/rumours-news/376433-af447-23.html#post4980356)

ClippedCub;
Thanks for your descriptions - I apologize for leaving my question and post open to interpretation regarding the suggestion of a "flat" spin - it wasn't yours I know but it has been made. I understand the dynamics of swept-wing flight and what happens in the stall/spiral/spin, (dynamic chord on the outside wing etc) but I wanted to understand how, and what the potential was, for a transport aircraft to enter/sustain a flat spin, where the nose is level or higher than the tail, given "normal" dynamics. In other words, with structural damage as per the BOAC 707 over Fuji which was a falling brick, all bets are off. To me, a steep nose-down attitude reaching very high speeds very swiftly and requiring great altitude to recover from, is far more likely an outcome from any non-recovered stall.

I'm using Davies' book but if you can point to other literature, I would be grateful.

PJ2

DorianB

18th Jun 2009, 19:50

http://i635.photobucket.com/albums/uu79/DorianBanks/th_BEADepthChart.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=BEADepthChart.jpg)

SaturnV

18th Jun 2009, 20:00

Dorian B, the red dots are body recovery points? (I assume a dot could be more than one body at that location.)

Is there any list that matches the recovered items with the number shown for the item? And do you have any information on whether the numbered grey dots displayed are for the relatively larger sections of recovered wreckage?

DorianB

18th Jun 2009, 20:12

augustusjeremy

18th Jun 2009, 20:17

99,9% probability of a meaningless relationship but who knows:

ISIS is linked to Adirus 1 and 3
IR2 (Adiru2 ?) was reported faulty by IR1 (ADIRU1) and IR3 (ADIRU3) (Is it true ?)
EFCS1 reported problems EFCS2 was having with pitot( - s ?) (Is it true ? Is EFCS2 linked to ADIRU2 ?)
ISIS has problems with gyroscope (comparison with ADIRUS 1 and 3?)

It is probably nonsense but I will post anyway.

PJ2

18th Jun 2009, 20:30

ttcse;
While I understand that basic crude swept wings tend to tip-stall and subsequently the center-of-lift goes forward (enhancing the unhelpful nose-high attitude), are the swept wings of modern transports fairly immune from this with normal loading?
I was wondering about this as well - Davies discusses this at length in his section on stalls and super-stalls but the last (3rd, 1971) edition was more than thirty-five years ago; the design of wings and chord sections has changed dramatically since then and I would like very much to know what handling characteristics might be reasonably expected during the approach to stall and the stall itself and the characteristic of pitch-up as the stall moves inward from the tips and the center of lift moves forward.

This may be tech-forum stuff but it is a current topic here so once again I am seeking a contextual response rather than a non-related discussion on the stalling characteristics of modern transports.

aguadalte

18th Jun 2009, 20:41

aguadalte:

Quote:
Just a word to clarify that ISIS doesn't receive "attitude from internal gyros", it receives inputs from ADIRU1 and 3.
:=

The problem, as said earlier, is that ISIS containts are classified. I know it sounds weird but again, no one opens up this box !!

While it is true that it gets inputs from ADIRU 1 and 3, it is also true that it contains gyros !!
What inputs from ADIRUs ? I have no idea because the Airbus doumentation does not describe this. It could be to compare data, or to receive inputs from AOA and such....

It also is linked to ILS receiver 1 for example as you can display the LOC/GS sacles and diamonds.

As a matter of fact, ISIS needs to "align" its ATTitude on power up, and has an in flight ATT re-initialization button as well.

So the GYRO, Attitude information IS definitely self contained !

It is a BACKUP instrument. We know how to use it, we know what can go wrong with it, we do not know how it works inside !
Do we really need to ? not so sure.

By the way it is powered by BOTH the DC ESS bus and Hot Bus 1

Captainflame:
My apologies, I may be wrong. (damn! I hate when I'm wrong:ugh:) And I hate (!) that "need to know - nice to know", Airbus philosophy :*)

capeverde2008

18th Jun 2009, 21:16

Quote from Captainflame:

"Weather analysts report that the Convective weather pattern that night in that area did not present anything out of the ordinary, everyday equatorial storm system."

This is just the possible complacency I have mentioned in previous posts.... there is no such thing as 'everyday equatorial storms'. These storms happen frequently and their activity vastly exceeds the structural integrity of most commercial aircraft. Full Stop! Wise up please to some sort of 'go-ahead-itis'.

NO COMMERCIAL AIRCRAFT SHOULD GO WITHIN 100nm LATERALLY of CB - ICTZ (Tropical Cumulo-Nimbus clouds) activity.....for any reason...FULL STOP. NEVER, EVER, don't even think about it.... or trying to overfly it. That is from MANY years experience and many grey hairs of wisdom!!

Many pilots/carriers have lived to tell the tale of bizarre encounters in this area. ICTZ CB activity that spans the globe around the equator is where Hurricanes/Typhoons form. I strongly feel that any FD crew operating anywhere in this area should be given specific AVOIDANCE weather understanding. Daylight views are one thing, however, night time...as many long-haul flights operate over....all one relies on is forecast, PIREPS, experience and WX Radar.

No matter how fancy and colourful the radar is; unless you are trained to interpret it accurately and trust that it is accurately reporting; you only have 'historical' data to go by. Vast activity happens in mere seconds at equatorial levels from a few hundred feet AGL to over 50,000ft.

At night, even with the most sophisticated WX radar, reports etc., what you see on screen is only an INTERPRETATION of what is going on. Dark red means dark red. Light green means light green. Both could indicate activity beyond the structural capacity of the commercial aircraft. Maybe this is also a speciality with new part-composite structures, such as used by Airbus & others in contemporary designs....whereby....the actual structure is not designed to 'X' structural limits...it is designed to be used in conjunction with 'damping devices' such as spoilers operating to assuage (lessen) vertical forces, for example.

We can get into many complicated design/structural issues if we want in this forum. However, there just seems a primordial lack of concern about flying into weather in the ICTZ, specifically anywhere near CB reports.

If you don't go anywhere near (as above), even if that means diversion/turn back you will have many happy landings and happy PAX (and fellow crew), who haven't endured many long minutes/hours of uncomforteableness/fear.

I rest my case.

Aiming for 'smooth as Silk' until I die and then let me be lifted to the heavens from mother earth in the widest ICTZ storm....sorta thing, guys & gals.

Sincerely,

capeverde2008 :=

wilyflier

18th Jun 2009, 21:20

Looking at DorianB`s charts (20.47, today thursday june 18)
With a certain amount of approximation....
I take estimate last position report as 0210/04
Distance of first centre of debris June 06 from above,66km
Distance travelled June06-07...........................9km
........................ June 07-08..........................30km
.........................June 08-09...........................35km
.........................June 09-10...........................50km
Any drift from Jun01-06 may be guessed at roughly 13km per day if impact at Last Pos Rept....
OR if drift was 9km per day or less ,impact was just 20 km from LPR,
At the most around 50-60 km beyond LPR if practically no drift; less than 4 mins at Mach.8

ACLS65

18th Jun 2009, 21:36

This is reassuring (not): "An A340 operator reported the loss of ISIS followed, during the same flight, by the loss of all Electronic Instrument System (EIS) Display Units (DU). The failure mode of ISIS has been identified as a time counter fault after 145 hours of ISIS continuous power supply. AD/A330/28 (DGAC AD F-2004-117) mandates the operational procedure to recover lost EIS Display Units, pending a new EIS standard addressing the misbehavior. Situations where EIS DUs and ISIS are simultaneously unavailable may result in hazardous consequences in certain phases of flight. This Directive requires a periodic on ground-reset procedure to prevent the ISIS failure by clearing the time counter." AD/A330/42 Integrated Standby Instrument System 13/2004 The temp fix was to cut power to the ISIS for more than 5 secs so it would reset.

Dutch Bru

18th Jun 2009, 21:41

Yes, there was quite a discussion before on the mobile crew rest (MCR), which posts have been deleted, including mine, one of which gave the link to the similar MCR on the 340 now reposted by PJ2. Thanks for that.

In the previous posts it was confirmed by a fellow poster, obviously in the know, that MCR on Air France's 330's are positioned below deck at the hight of the 3L/R doors just aft of the wing box.

The debris photo of part of the MCR outside panel as reposted by lomapaseo seems to show heavy underside damage, possibly caused by this part coming loose from the structure that is locked in the floor of the hold.

Just as lomapaseo theorises that this supports inflight break up, I'm still there with a theory of a low vertical and horizontal speed (mostly) intact, tail first impact (making the V/S breaking away, while damaging the rudder base), followed by a further deceleration in which the a/c broke aft of the wings, releasing the cargo container there (inter alia).

Obviously the real and heavily filled cargo containers crushing the MCR, allowing the part on the photo to break free.

Just trying to see what could have happened.

einhverfr

18th Jun 2009, 21:43

@acls65:

I am surprised that timer wraparound faults are not addressed better.... It is possible that this is a similar issue here which lead to a tragic ending because it happened in bad weather.

captainflame

18th Jun 2009, 21:44

Capeverde2008:

I was merely refering to weather analysts pont of views. TO THEM it wasn't any particular CB cluster. As you say they happen frequently...you mean like in "everyday" ?:cool:

It was in response to a previous post from a non aviation professional who was mentioning typhoons or hurricanes !!

I was certainly not implying that these things shouldn't be avoided.

So relax, avoid as you wish, retire soon, happy landings !;)

ClippedCub

18th Jun 2009, 21:55

PJ2, ttcse, others,

Not familiar with the referenced book, my experience comes from having an interest in the manner since I like aerobatics, working in the industry 30 years, and proprietary manufacturer data.

The tips of swept wing transports stall first due to induced flow upwash angles. You all know the leading edge produces negative pressures. Pick a wing station inboard. As the air passes next to that inboard station, but outboard from it, it senses that negative pressure and starts flowing upward. Therefore, that wing element sees a slightly higher local AOA. This follows for each chord wise strip, or tiny section of wing, and by the time you reach the tip, the induced upwash can be 2-4 degrees higher than the reference airplane AOA at cruise conditions. Wing twist is set by this for best efficiency. As you increase AOA in the clean configuration, the tip will stall, with an attendant nose up pitch break, and is a terrible stall characteristic. Good reason for not stalling a swept wing transport in the cruise configuration. True now as it was in the beginning.

Tip stall is mitigated by the use of flaps and slats for the T.O. and lndg configurations, and are used to tailor acceptable stall characteristics.

Flat spins are sensitive to cg position and power effects. The aerobatic single engine airplanes I've flown won't go flat without almost full power. This is due to prop wash increasing elevator power, forcing the tail down. Some of them are driven by prop centrifugal force and torque, like the Russian monster, the Yak-52. Some will recover very quickly just by chopping power and applying corrective controls. The Yak-52 wants a few more turns before it recovers once it's wound up.

You don't have a prop on an airliner, but there are underslung engines providing a nose up moment. Is it enough, maybe, nobody's ever done the math. One thing though, you don't want these big airplanes spinning. Boeing experience on the 707 taught everyone that. The 707 did a snap roll a couple of different times. They recovered the airplane due to the design requirements of the time. Think they certified under CAR 4a. Much more demanding than the current regs, so the 707 is a tough bird, still significantly damaged, but it returned the crew.

Not hard to envision current airliners tearing themselves apart in a spin. The engines would go, moving cg aft, maybe it goes flat. And/or the empennage would go, and/or the nose breaks lose. Who knows. The crew would be under tremendous g load in a fully developed spin. Due to inertia and mass, it would take a couple of turns to really wind up.

Hope this helps.

DorianB

18th Jun 2009, 22:09

Very interesting article on the US Coast Guard providing drift analysis technology and support:

Air France Flight 447 Recovery Assisted By U.S. Coast Guard And (http://www.govcon.com/article.mvc/Air-France-Flight-447-Recovery-Assisted-By-0001?VNETCOOKIE=NO)

PJ2

18th Jun 2009, 22:11

ClippedCub - yes, it does, many thanks for your time and effort. We'll see what else emerges in the next weeks.

Sorry, the book I'm referencing is "Handling the Big Jets" by D.P. Davies, first out in 1967, last ed. 1971 - can be found online and is the best (and, perhaps aside from "Flying the Wing"), only book on handling large transports which doesn't cater to manufacturer spin but is instead written with great knowledge and even humour, to airline pilots.

It is both the easiest thing and a very difficult thing to conjur a series of circumstances from the first hint of difficulty to initial degradation to the beginning of the actual accident sequence. One thing is for sure - there's a lotta people out there including cockpit crews, "into the books".

ClippedCub

18th Jun 2009, 22:18

"Handling the Big Jets" by D.P. Davies

If it's stood the test of time, must be good. The physics don't change so the book will still be valid.

Another geometric characteristic that would promote flat spinning in airliners would be the fuselage cylinder ahead of the wing. At extremely high AOA, it would produce a drag force in the positive lift direction ahead of the cg.

BOAC

18th Jun 2009, 22:20

we know what can go wrong with it,......................
Do we really need to ?..................

What is apparent here is that no-one DOES seem to know what can go wrong with it, so the answer to your second question is a resounding YES!

Wth such a spider's web of computer cross-chat, it is surely vital to have some sort of independent backup for that 'Titanic' moment when the infallable safety net breaks. Even basic uncorrupted attitude would be a start.:ugh: TAS and ALT are not essential, you can live without profile rate for quite a while.

While one can guess, I do not know what is meant by the terms, "accelerometer" and "gyrometer" in the "ISIS" box. The key in that understanding is, of course, whether or not if ADIRS 1 & 3 fail, does the standby horizon fail? - up until the last week or so I had, in my blissfull ignorance, assumed that ISIS would have a mini-platform, thus requiring those "accelerometer" and "??gyrometer??" in the 'box'. Now I'm left wondering.

icarusone

18th Jun 2009, 22:47

ISIS Attitude information is independant of all three of the ADIRUS.

Regarding the ADIRU 1 + 3 inputs into the ISIS:

The ISIS has 2 possible power sources (ESS and Hot Bus)

When passing through 50kts the power source for the ISIS changes from the ESS to the Hot bus. How does it know when to do this? The airspeed information from ADIRU 1 + 3. Hence the reference to ADIRU 1 + 3 inputs.

This thread has gone interglactic in its amount of information. It reads like 80 people yelling at once. Good luck to you all and I hope we find the cause soon.

A33Zab

18th Jun 2009, 22:47

ISIS INTERNALS:
http://i474.photobucket.com/albums/rr101/Zab999/A330aviosystems2003_Page_068.jpg
ISIS BREAKDOWN:
http://i474.photobucket.com/albums/rr101/Zab999/A330aviosystems2003_Page_069.jpg
ISIS INTERFACES:
http://i474.photobucket.com/albums/rr101/Zab999/A330aviosystems2003_Page_072.jpg

AIB Presentation 2003,

Considering connection with IR Bus ADIRU 1 / 3,
besides the supply switching.

AMM:

Two ARINC 429 high-speed buses provide the ISIS indicator with the ADIRU ground speed information.
This information is used as a backup source for ISIS ground/flight condition.

and,

Optional magnetic heading.

The magnetic heading provided by the IR1 or IR3 enables the display of the magnetic heading information.
.......
In case of detected failure of the selected ADIRU, a red HDG Flag is displayed in place of the magnetic heading indications.

A33Tech.

Rananim

18th Jun 2009, 23:29

Just a word to clarify that ISIS doesn't receive "attitude from internal gyros", it receives inputs from ADIRU1 and 3.

Someone please clarify.Is the ISIS a mini PFD or a genuine standby instrument?This is at the heart of the matter.Forget wreckage,concentrate on what the crew had available to them in the last minute.This will tell the story.

This is what I could gather :
at 0210Z : from bottom to top :
- AUTO FLT AP OFF
-F/CTL ALTN LAW
- FlAG ON Capt PFD
- FLAG ON F/O PFD
- AUTO FLT ATHR OFF
- NAV TCAS FAULT
- FLAG ON CAPT PFD
- FLAG ON F/O PFD
- F/CTL RUD TRV LIM FAULT
- EFCS2...1..EFCS1...AFS
- EFCS1...X2..EFCS2X

at 0211Z :
- FLAG ON CAPT PFD
- FLAG ON F/O PFD

at 0212z:
- NAV ADR DISAGREE
- ISIS ....ISIS
- IR2...1,EFCS1X, IR1, IR3

at 0213Z :
- F/CTL PRIM1 FAULT
- F/CTL SEC1 FAULT
- AFS 1 FMGEC1

at 0214z:
- MAINTENANCE STATUS
- ADVISORY.../...

Above is ACARS summary from Lemurian.

Question(s) for Airbus pilots:

a)data for triple pitot heat failure is surely relevant here;not what happened but it amounts to the same thing.In that case,what it says is that one of the ADR's should be turned off to trigger the ECAM "ADR DISAGREE".If icing anticipated,turn off 2 ADR's?Why?Does it not follow that the 02:12 ACARS message "NAV ADR DISAGREE" was in response to pilot action?ie pilot de-selects ADR(s) OFF.If the multi-pitot failure/blockage theory is correct,theres nothing for the computer to find disagreement with.Theyre all three plain wrong.So the pilot must intervene to generate the ECAM warning.Is this correct?

b)It mentions it again for dual pitot heat failure;the inherent risk is that the computer will lock out the one remaining good ADR.So the pilot must turn off one of the faulty ADR's and trigger the NAV ADR DISAGREE which in turn will lead to ADR CHECK procedure.
So NAV ADR DISAGREE warning can either be computer-generated OR pilot-action generated(Pilot switches OFF faulty ADR).Correct?

d)Now that one ADR has been disabled and the ECAM warning generated what next?For ALT LAW to kick in,there must be disagreement between 2 remaining ADR's,either speed or AoA.If speed disagrees in the remaining two ADR's,crew fly unreliable airspeed procedure.If speed does not disagree,AoA is culprit,and crew ignores spurious STALL warnings(Air Caraibe).Is that about right?

e)The ECAM message in the Air Caraibe incident was FCTL ADR DISAGREE,not NAV ADR DISAGREE.What does this indicate?How telling is it that both 447 and Caraibe began with AP/FD disconnects?

f)In ALT LAW roll control is same as for Direct?Please enlighten.Sensitivity issues?

g)With a CAS of say 90 knots on all 3 ASI's at time of RUD TRAVEL LIMIT warning,could rudder deflection of 31 degrees been mandated by the computer as the limit?

h)What is the QRH procdure(2.20) for flight with all 3 ADR's out.ECAM apparently only covers single ADR op?Would 3 ADR's out=Direct Law?

I know Im out of my depth(never piloted/travelled on an Airbus) but no-ones asking questions that relate to what the crew had available to them in the last minute.What did they see??

p51guy

18th Jun 2009, 23:44

NO COMMERCIAL AIRCRAFT SHOULD GO WITHIN 100nm LATERALLY of CB - ICTZ (Tropical Cumulo-Nimbus clouds) activity.....for any reason...FULL STOP. NEVER, EVER, don't even think about it.... or trying to overfly it. That is from MANY years experience and many grey hairs of wisdom!!

I guess you never fly through Texas with thunderstorms as big then. You would have to deviate over Oklahoma with those parameters.

A33Zab

19th Jun 2009, 00:13

http://i474.photobucket.com/albums/rr101/Zab999/A330aviosystems2003_Page_061.jpg

A33Tech.

HarryMann

19th Jun 2009, 00:27

Rananim

Good post there, these are the questions many others would like to see answered too, I suspect.

Hyperveloce

19th Jun 2009, 01:33

The Air Caraibe report shows that the NAV ADR Disagree is a consequence of clogged/iced Pitot tubes and static ports and slightly different patterns of errors on each ADM generating the disagreement, making air speed and maybe also barometric altitude erroneous/inconsistant (this may be a potential problem for the TCAS ?). The NAV ADR disagree did not require a manual intervention of the pilots on one of the ADIRUs to appear.
All the faulty instruments, the ADIRUs, the ISIS and the TCAS appear to be inputed by Pitots, static ports or barometric pressure sensors. What if these Pitots and the airframe (static ports) were rime iced crossing a cumulonimbus ? If in the mist of a tropical cell, subjected to turbulences, severe icing conditions, a gradual deprivation of all air references (air speed), followed by a cascade of faulted nav instruments, multiple alarms in the cockpit, unreliable/unconsistant indicators, loss of flight assistances/protections, maybe a stall due to erroneous air speed which surprised everyone on board ? (pilots trying to understand/cope with the multiple failures, air crew). A stall followed by a dive, resulting in an overspeed during which the vertical aileron (and the spoilers ?) may well have been ripped off (not protected anymore against excessive manoeuvers in alternate law) before a critical airframe break up.
Hope these black boxes will be recovered soon.
Jeff

augustusjeremy

19th Jun 2009, 01:48

All the faulty instruments, the ADIRUs, the ISIS and the TCAS appear to be inputed by Pitots, static ports or barometric pressure sensors.

The ISIS and IR2 faults were related to inertial reference faults/disagreements. I can't see how airspeed and barometric data would per se generate them.

If they were later caused by a "shaking to hell" a/c it's another story...

Iceman49

19th Jun 2009, 03:06

Aquadalte: "If this aircraft was equipped with ISIS, it was surely also equipped with Back-Up Speed Scale and Back-Up Altitude, that displays on PFD's and gets information from AoA probes and GPS, respectively.

This is very important, once Back-Up Speed Scale and Altitude are only displayed when ALL ADIRU's are switched OFF. The old procedure (for the stand-by horizon equipped aircraft), would call for the trouble-shooting of the IR fault, and in case of all confirmed to be faulted, one would be advised to switch off those connected to Captn PFD and FO PFD, i.e., IR1 and 2. This would allow the aircraft to revert to Alternate Law.

This system (although brilliantly designed) seams to work fine in rather smooth air and on flight simulators, but I find it very difficult to see it properly working in a heavy turbulent environment, as seemed to be the case of AF447."

Believe that the Back-Up Speed option was available in 07, the ISIS does indicate Speed/Altitude and Attitude...the instument is only about 1.5" square.

grumpyoldgeek

19th Jun 2009, 03:31

Will Fraser

19th Jun 2009, 04:18

I'd like to direct a comment toward the VS/Rudder separation. From AA587, we know the failure was complete, and purportedly caused by pilot input beyond structural limit. Here, we know the failure was complete, though the cause and sequence is unknown.

A short aside re: MD11 gear. In Narita, one noticed how astonishingly robust the NG and one of the MG were, the nose gear remaining attached even after that last horrific nose plant, the Main pushing up and through the main spar of the wing. BA038 lost the gear and saved the hull.

Here's the thing. The composite VS is exceedingly strong, as well as relatively light, and demonstrably resistant to failure except at the root, where it attaches to the fuselage. It remains pristine, not a crack in its skin.

Its failure at the root is obviously related (Lateral failure, if such was the case, as I believe) to its leverage on the root, a tall structure that is acting through its moment arm on a robust attachment.

I am pointing out that its only failure was complete; it resisted until the total failure was unavoidable. If however the structure was designed to have top down sequential failure, a component at a time, each loss of surface area would reduce its advantage on the root, allowing for the remainder of the fin to operate in reduced effectiveness, but allowing for directional stability. Something as simple as two or three parallel seams such that the first piece to depart might be the topmost one meter, the next failure point halfway, until the moment arm was short enough that the fuselage attachment would be virtually failure proof, though providing very limited D/S.

I can't take my eyes off that nearly perfect fin.

One can envision 587 retaining some fin if not rudder. Rudder is a trimming device, without it things are difficult, lose the VS and you lose the a/c.

WF

ZeeDoktor

19th Jun 2009, 05:02

A very interesting suggestion, allowing for partial disintegration of the VS. I suppose it goes against the design philosophy that the main flight surfaces were meant not to fail, not as a whole nor in part, at all. That might need to be reconsidered.

I wonder however whether removal of the VS as we see it in the AF case would not rupture the hydraulic lines. B, G and Y HYD systems are all operating the rudder surface in the A332. If the entire VS was ripped off, I'd imagine that would depressurize B, G and Y hydraulics, and that in itself should be triggering a whole host of ACARS warnings back to base?

Also, the rudder travel limiter remembers the last limit in the case of a double SEC failure, and won't reset and allow full travel until the slats are extended.

Based on that rational, I think we are looking at the VS separation being an effect of the sequence of events after departure from controlled flight rather than a cause.

Cheers

Doc

ACLS65

19th Jun 2009, 05:48

Just to follow on with ZeeDoktor...

If the VS failed early on would the A/C have remained stable enough to transmit the ACARS msgs?

Also from the pics of the VS the rudder is damaged at the lower rear edge which could mean the VS failed first at the leading edge and rolled back over the tailcone as opposed to AA587 where the rudder is gone completely and the VS was apparently broken of from side pressures.

cpdlcads

19th Jun 2009, 06:52

On the 330/340 try putting ''aoa'' into the ACMS on MCDU 3. This gives a readout of current angle of attack which at 350-370/.81 usually reads 2.2 to 2.3 degrees. Could help with loss of all speed/mach and/or PFDs. Obviously only good for benign conditions and you would have to do it in advance as you cannot do it in the middle of the emergency. But don't think it would've helped in Af's extreme condns....

WhyIsThereAir

19th Jun 2009, 06:57

> If the VS failed early on would the A/C have remained stable enough to transmit the ACARS msgs?

This could be reworded as "is relatively stable flight possible without a rudder and VS?" A B52 managed it once, but I suspect in general it would be a neat trick, especially in the middle of a storm at night.

That said, if the plane was stable enough to send messages and the VS decided to leave suddenly, I'd guess that it might remain stable enough to send messages for another few seconds, maybe longer. So if the VS had been the first thing to go, there is a reasonable chance that we would have seen a message about it. Instead we have a cabin descent speed warning.

Note that when the VS left it ripped up the back of the plane. The forward bolt support structure is very near the aft pressure bulkhead. So it might have peeled open the aft bulkhead. That could relate to the early reports that the bodies being found were from the back of the plane. Its possible the hole might not have been all that big, so it might have required some seconds to depressurize the plane.

Old Engineer

19th Jun 2009, 07:48

The ISIS, if operational and not in need of reset, can on its own determine all the correct indications to display on its face (pix by A33Zab at post 1940), except that the indication of IAS and FL depend on the probe PITOT3 and the probes STATIC3 (same ref post 1935). [If these probes are giving erroneous readings, there is in theory some ability to detect gross divergence from speed made good and true altitude-- I cannot say if this is implemented in some way, or if this display can show that.] I do not know the effect of the loss of bus power; is there an internal floating battery or capacitor source, and of what duration?

It is reasonably clear that the inputs from ADIRU-1 and -3 are used to initialize ("reset" button) the ISIS before each flight (to the heading, pitch, roll, and altitude of the standing A/C), and that if these inputs are lost, an ISIS FAIL message to ACARS may be generated for maint, if for no other reason than possible loss of ability to make this AF SOP required reset at the next terminal. Obviously, in an emergency, a reset in flight into an erroneous input from either ADIRU needs to be avoided, and in general should be unnecessary.

So the questions are:

1. Is an inflight erroneous reset blocked by disagreement of ADIRUs 1 and 3? Or otherwise?
2. Does crew training include instruction on how, when, and when not to make inflight reset?
3. Does crew training include how and when to bring the ISIS up for flying, if needed?
3a. Or how, when, and why it becomes the instrument for flying, if automatic?
4. Does crew training include mention that all the ISIS displays are normally accurate (IMO), except that IAS and FL may err due to probe icing?
5. Is there any SIM training with ISIS as the only flight instrument? with its ILS feature?
6. [I omit mentioning again all the proper flying procedures covered by others.]
7. Does the QRH cover all this? Can or should it be memory trained?
8. Are electric power issues covered? LCD screen readable with flashlight if necessary (that external 5vac)?

And a final question:

9. If an ISIS FAIL message is generated for ACARS due ADIRU input fail (see above), does it blandly repeat on the PFDs in just those words? Can we tell from the ACARS? (I know... not easily.)

[I recall a respected pilot here saying we should have a TV record of just what appears on the PFDs. The point is, is there an ISIS FAIL on the PDFs, when in fact the ISIS is functional? And does the SIM replicate the A/C in this detail?]

BTW, the 3 gyros are not one operational gyro and 2 backups-- all 3 are operational with specific functions. That makes it self-sufficient as to A/C attitude. It isn't actually necessary to know more than this to know that it doesn't need the ADIRU inputs to generate its display.

Hope this helps. OE

BOAC

19th Jun 2009, 08:03

SO, back to ISIS and Ranamin's and my question. A33Zab appears to show that aguadalte's posts are incorrect, and that ISIS does have its own IRS system and should be capable of providing basic attitude info in the event of failure (or isolation) of all 3 ADIRUs. The $10,000 question, of course, is what 'interference' does the aircraft 'management' software place in the way of ISIS ACHIEVING this aim? 'icarusone' and AZ tell us that it is possible that the Hot battery bus supply could have been 'interrupted' due to the air/ground switching (was 'ESS' unaffected?), and of course there would appear to be no heading info with loss of the 2 ADIRUs, so back to the standby compass:eek:.

No, this does not 'solve' the accident by any means, but if the ISIS was somehow 'prevented' from providing this basic information it makes an accident far more understandable given the other system failures they appear to have suffered in those weather conditions. The whole software side is indisbutably very clever, but IF it has been coded on the basis that there are so many redundancies and backups that 'nothing can go wrong', is it time for a big red switch which says 'take ALL the computers out of this and give us Basic information so we can try to fly it'? NB That is for ALL modern aircraft of whatever type/manufacture.

Lots of fingers crossed for the search.

A different question for those familiar with that route. From what I can make out in terms of where this might have occurred in the actual area of CB activity, carrying on on track after 'recovery' from whatever happened would appear to be a better weather solution than turning back to the mainland. How would this fit with a possible 'worse case' ETOPS fuel scenario ie low level 2 engines vis a vis ETPs and excess fuel, and where would ETP 1 be likely to be in relation to TASIL?

captainflame

19th Jun 2009, 08:36

Old Engineer:

Thank you for your post !!

I think we've all made it CLEAR to non airbus / non ISIS familiar colleagues (BOAC and others..) that the ISIS is a STBY / back up instrument independant from ADIRUs as a SOURCE of displayed flying DATA.

1. Is an inflight erroneous reset blocked by disagreement of ADIRUs 1 and 3? Or otherwise?
No idea. But I wouldn't think so. It's independant ! The inflight reset is made in case of ATT flag on the ISIS.
From FCOM: ATT flag (red) on ISIS appears when attitude data is lost, the red ATT flag appears. ATT RST The attitude indication can be reset by pressing this pushbutton for at least 2 seconds. The aircraft must be level during this procedure. During the reset time (approximately 10 seconds), the "ATT 10s" message is displayed on the screen. This pushbutton is also used to realign the system, if excessive aircraft movement is detected during the alignment phase.

2. Does crew training include instruction on how, when, and when not to make inflight reset?
well, not me....

3. Does crew training include how and when to bring the ISIS up for flying, if needed?
3a. Or how, when, and why it becomes the instrument for flying, if automatic?
When attitude/altitude/airspeed reference are lost from tripple IR failures, tripple ADR failures, blank DUs etc... (these are no longer available on PFDs basically)

4. Does crew training include mention that all the ISIS displays are normally accurate (IMO), except that IAS and FL may err due to probe icing?

Yes !

5. Is there any SIM training with ISIS as the only flight instrument? with its ILS feature?

Not on a recurrent sim training basis...maybe it will be in the future now !

6. [I omit mentioning again all the proper flying procedures covered by others.]
7. Does the QRH cover all this? Can or should it be memory trained?

Flying by reference to stby instrument in general is not a memory item. it's pretty much a reflex to go to the available information remaining. Nothing in QRH re:ISIS.

8. Are electric power issues covered? LCD screen readable with flashlight if necessary (that external 5vac)?

electric power: as said, DC ESS BUS + Hot Bat1 backup.
Yes you could read the LCD with the flash light.

And a final question:
9. If an ISIS FAIL message is generated for ACARS due ADIRU input fail (see above), does it blandly repeat on the PFDs in just those words? Can we tell from the ACARS? (I know... not easily.)

There is no Flag on PFDs concerning ISIS. Failures/errors pertaining to ISIS are displayed flags on the ISIS LCD itself. Nothing on ECAM either,
ACARS message re:ISIS, we need a decode. Could be the Airspeed flag if STBY pitot has a problem, as simple as that.

By the way, NAV ADR DISAGREE can come up with 2 erroneous AOA data as well (ADRs).

OK. My opinion is that is all else fails, the ISIS is available to maintain at least the attitude of the A/C.

I think we can leave the ISIS to rest now ! no ?:rolleyes:

h3dxb

19th Jun 2009, 10:06

Gents just to shed some light:

Post#1910

The problem, as said earlier, is that ISIS containts are classified. I know it sounds weird but again, no one opens up this box !!

It is true ,that an ISIS falls under the US expert control request due to this fancy "inertial Measurement unit" but it can and will be opened for repair. Actual there is a reapir manual for this.

While it is true that it gets inputs from ADIRU 1 and 3, it is also true that it contains gyros !!

Not so true. It does not contain gyros. It's containing a IMU (Inertial Measurement Unit) described as "
Inertial Measurement Unit (IMU). It contains three single-axis rate sensors and their temperature
probes, two acceleration sensors and their temperature probes, one IMU board and one mechanical
structure. This assembly is connected to the Programmed Motherboard "

It is not an IRU (Inertial Reference Unit) it ONLY detect it's position in space, not movement in it. And in regards to ADIRU inputs.
ADIRU (IR1 or IR3)

Two ARINC 429 high-speed buses provide the ISIS indicator with the ADIRU ground speed information. This information is used as a backup source for the ISIS ground/flight condition.
In normal configuration, the parameters used by ISIS indicator come from the ADIRU 1.
When a failure is detected, switching to the ADIRU 3 must be done manually through the ATT/HDG selector switch on the SWITCHING panel.

But U can ask me every time :ok:

BOAC

19th Jun 2009, 10:24

I think we've all made it CLEAR to non airbus / non ISIS familiar colleagues (BOAC and others..) - problem seems to be you have NOT made this clear to those claiming to be current A330 pilots! Who am I to believe? You clearly state that aguadalte is wrong. He probably thinks you are.I think we can leave the ISIS to rest now ! no ? - I am left wondering whether the crew of 447 were in your Airbus tech class or in ag's: I say No!

captainflame

19th Jun 2009, 10:25

H3dxb:

Brilliant ! finally I find out what's inthere !

Yes it's not on IRU. But it provides "gyroscopic attitude information" right ?

Thanks for the post !:ok:

BOAC

19th Jun 2009, 10:34

cf - you must have missed #1934? A superb description of the system.

It would seem that once alignment is complete (and presumably kept updated by the IRUs, the Quartz Rate Sensors (modern equivalent of laser ring) will in fact provide attitude information as would an IRU. The Q is what happens if/when the IRU input is blocked or fails.

EDIT: Just seen your post - it does NOT contain any 'gyros'. Read h3's post again?

captainflame

19th Jun 2009, 10:39

BOAC:

Sorry to say but if you can't make up your opinion on how it works and answer most of your questions on ISIS, then I am at loss to help out.

Following the latest ISIS post by h3dxb (#1951), and taking into account other well informed posts (even excluding mine if you wish), you can have a pretty good idea on how the ISIS functions by now.

Key fact is it contains a gyro, indicating attitude. I never said it's an inertial plateform !! Aguadalte implied it got its attitude info from ADIRUs, and that's plainly false. He standed corrected earlier. No problem.

Fact is, tech info on ISIS is not disseminated as profusionnally as one would wish.

Personnally, I learned more now on ISIS than on any other ground course I followed recurrent or not !

captainflame

19th Jun 2009, 10:52

I think we are talking about the same thing. Confusion with terms perhaps ?
For me a gyro, whether spining, laser or quartz, provides attitude info.

the Quartz Rate Sensors (modern equivalent of l@ser ring) will in fact provide attitude information as would an IRU

For you as well looks like...

As to the Q question: i don't have an answer.

h3dxb

19th Jun 2009, 11:23

Gents

Fully access to Manufacture documents . It looks like the IMU is equipped with single axis Sensors working as Gyrometers.
An IRU detects it's position in space and movement through it, an attitude indicator only it's position.

Standby horizon function

The ISIS indicator can operate from -180 to +180 deg. in pitch and roll without deterioration.
-
gyrometers (3): a monitoring is triggered when the angular speed in x, y or z axis becomes greater than 95 deg./s. ISIS can follow a 10,000 deg./square second angular acceleration.

-
accelerometers (2): the associated monitoring is released when the constant acceleration in x and/or y axis becomes greater than 3.25 g.

If this monitoring is triggered, the "WAIT ATT" message is displayed.

If the conditions become normal again and if the attitude performance remains adequate for 10 seconds , the "WAIT ATT" message disappears and is replaced by the horizon display.

Otherwise, after 10 seconds or if the attitude performance is affected, the attitude function is considered as failed and the "ATT:RST" message is displayed in place of the "WAIT ATT" message

Pressing the RST pushbutton switch more than 2 seconds in steady flight quickly resets the attitude information.

Anyhow, it is an seperate standby unit, even when connected to several computers, it acts alone and gets it's physical infos from it's on sources.

BOAC , I hope this Info about the quick reset possible in flight answers yr question. I think steady flight means in this philosophie less than 3.25 g.

kind regards

tubby linton

19th Jun 2009, 11:37

I remember an article from Aviation International News from a number of years ago regarding the use of accelerometers in standby instrument systems.The article went on to state that the accelerometers were identical to those used in car airbag systems and that they isis could run off a watch battery for 24 hours. Unfortunately I have been unable to find the article

aguadalte

19th Jun 2009, 11:47

Quote:
While it is true that it gets inputs from ADIRU 1 and 3, it is also true that it contains gyros !!

Not so true. It does not contain gyros. It's containing a IMU (Inertial Measurement Unit) described as "
Inertial Measurement Unit (IMU). It contains three single-axis rate sensors and their temperature
probes, two acceleration sensors and their temperature probes, one IMU board and one mechanical
structure. This assembly is connected to the Programmed Motherboard "

It is not an IRU (Inertial Reference Unit) it ONLY detect it's position in space, not movement in it. And in regards to ADIRU inputs.
ADIRU (IR1 or IR3)

Two ARINC 429 high-speed buses provide the ISIS indicator with the ADIRU ground speed information. This information is used as a backup source for the ISIS ground/flight condition.
In normal configuration, the parameters used by ISIS indicator come from the ADIRU 1.
When a failure is detected, switching to the ADIRU 3 must be done manually through the ATT/HDG selector switch on the SWITCHING panel.

Captainflame:
As written (by me among others) in previous posts, the ISIS is a self contained instrument providing Airspeed from stby pitot, attitude from internal gyros, Altitude from STBY static ports, and slip/skid info from accelerometers,
http://i277.photobucket.com/albums/kk76/batcave777/A330_ISIS_architecture_2009-06-1-1.png
(Since I have not much more than this on my FCOM)
Captainflame: What happens when ALL ADIRUS fail?

OleOle

19th Jun 2009, 12:08

h3dxb

But U can ask me every time
I'm not necessarily referenced by "U", but anyhow:

In an earlier post you stated that the SATCOM phased array antenna needs inertial reference to control it's beam steering.
http://www.pprune.org/rumours-news/376433-af447-77.html#post4997265

How then could it have been able to transmit ACARS messages stating that no inertial reference is available? Or am I missing something?

Rananim

19th Jun 2009, 12:29

Is the Qantas parallel now more compelling than other theories?
Erroneous AoA values are fed to ADIRU(s) leading computer to mandate unwanted and dangerous flight control maneuver.The vulnerability of the computer's "voting" system when faced with conflicting air data was highlighted by the ATSB.Spike values and hysteresis(lag) confuse the computer and it may de-select a good ADR and respond to a faulty one.Autopilot ON or OFF,doesnt matter.

However, it is important to note that in fly by wire aircraft such as the Airbus, even when being flown with the Autopilot off, in normal operation, the aircrafts flight control computers will still command control surfaces to protect the aircraft from unsafe conditions such as a stall.

BOAC

19th Jun 2009, 12:41

aguadalte - an even more confusing post! It has got gyros - it hasn't got gyros - it has got gyros.....

If I may divert momentarily, it is important here to differentiate between a gyroscope, which is a rate sensor, and a rate sensor (eg QRS or LRG), which is NOT a gyroscope. A gyroscope will maintain its attitude in a space frame and thus enable 'attitude' to be directly physically determined. A rate sensor, as in ISIS, can only offer displacement information FROM a known attitude, and requires a lot of software to produce the new 'attitude'. It lacks the vital 'rigidity' which the gyroscope has.

Back to 447 - I'm still not clear if we have an answer to what the software would have shut down or permitted in the way of information to the crew. Have we established BEYOND DOUBT that loss of pressure inputs to an ADIRU render that ADIRU unusable for attitude, either because it lacks some feed or because the system determines it to be 'unusable'? If the answer is yes, then we move on the the John Wayne scenario where the good captain is holding a torch in his clenched teeth and shining it on his only remaining attitude indicator. Does this definitely still function, or has HAL decided it too should be shut down because it has either faulty attitude inputs from the ADIRUs or faulty pressure inputs? I've been searching for info on the Qantas and Air Caribe 'upsets' to see what they 'lost' on the panel - anyone point me please?

Even with a better understanding of the systems, we are still basically in the dark as to what the software programmes are doing.

If breakup of the airframe did indeed occur, we really should be going BACK to how it got to that position in the first place, rather than discussing flat spins, VS failure modes etc. We need those recorders!

aguadalte

19th Jun 2009, 12:48

This is very important, once Back-Up Speed Scale and Altitude are only displayed when ALL ADIRU's are switched OFF. The old procedure (for the stand-by horizon equipped aircraft), would call for the trouble-shooting of the IR fault, and in case of all confirmed to be faulted, one would be advised to switch off those connected to Captn PFD and FO PFD, i.e., IR1 and 2. This would allow the aircraft to revert to Alternate Law.Dear Colleagues,
I have committed here a HUGE error! And I would like to apologize for that.
In the above said statement I said ALL ADIRU's are switched OFF and I meant to say ALL ADR's! (post #1907, now corrected to prevent others to be misinformed).

I studied the system again and noticed my mistake.
This led me to think that it is a common mistake in recurrent flight simulator sessions, to see flight crews, switching off one system, when they're actually thinking on another. (That is why we have the "confirmation" philosophy of asking for PF to visually confirm PNF actions, before switching of guarded or important systems when handling an emergency procedure)
I wouldn't like to speculate on that, (for the sake and honor to our fellow death colleagues) but, it now poses a reasonable doubt to me and a reasonable explanation for their lost of control of the aircraft.

Till now, I was strongly convinced that the failure of all IR's were responsible for the crash. Now I have a stronger and stronger (seasick) sensation that Human Factor was.

I'm sorry for being (as far as I remember) the first one to bring this speculative "explanation" for this accident. I do know that accidents have multi-causes. But, what if, instead of switching off the ADR part of the ADIRUS, they have inadvertently switched off the ADIRUS (or the IR part of the ADIRU's), in response to a Unreliable Speed Indication Check-List?

We all know how disturbing is to fly in turbulence.
Was the junior FO seated on the left seat?
Would the ISIS still give them attitude indication?

Rananim

19th Jun 2009, 12:53

http://www.atsb.gov.au/publications/investigation_reports/2008/AAIR/pdf/AO2008070_interim.pdf

safetypee

19th Jun 2009, 13:07

h3dxb, thanks for the technical description - ISIS.
Can you establish what the purpose of the temperature sensors is, and if these are internal to ISIS or require an external temperature input.
Is there a difference / switching routine between a failed input – e.g. ADIRS off, ARINC 429, and a working bus (but with corrupt data) i.e. a triple sensor might vote out a system by comparison (IAS) – a 'failed' system, but a dual sensor might pass erroneous data (TAT).

h3dxb

19th Jun 2009, 13:39

SAFETYPEE

h3dxb, thanks for the technical description - ISIS.
Can you establish what the purpose of the temperature sensors is, and if these are internal to ISIS or require an external temperature input.
Is there a difference / switching routine between a failed input – e.g. ADIRS off, ARINC 429, and a working bus (but with corrupt data) i.e. a triple sensor might vote out a system by comparison (IAS) – a 'failed' system, but a dual sensor might pass erroneous data (TAT).

Gents:
there is no description for the temp sensors in any manual. It looks like its for health monitoring of the sensors.
as there is also no CAS or TAT indicated no need for a temp input. the IAS is taken direct from the standby system.

When a part of the ISIS failed than this partial function is inop (degraded) not the whole ISIS.

except Powerloss >200ms this instrument is working.

BOAC

Have we established BEYOND DOUBT that loss of pressure inputs to an ADIRU render that ADIRU unusable for attitude, either because it lacks some feed or because the system determines it to be 'unusable'? If the answer is yes

The answer is NO. ADIRU= AD+IRU
Actually 2 boxes in one. The IRU part works seperately from the ADR Part. U can switch off the ADR part , but when U switch off the IRU, the box is switched off.

Once more ISIS is an Instrument which stands alone. And yes there is a lot of Software inside and ****ty expensive as well.

Have a good one, in 12 hrs I'm back on duty, and when it's a smooth day like today, I'll have time for yr questions :ok:

lomapaseo

19th Jun 2009, 13:47

I notice that many posters tend to peel the onion way too deep in discussing how and why planes are designed to break apart.

The investigation is still wide open to a myriad of possible causes some remote and some more probable. As debris is found and analyized by the Airbus structural experts the probability increases or decreases for the various theories. But they will remain as theories (using up all kinds of thread pages in this forum) until/(unless the main wreckage on the bottom of the sea is found and photographed.

Thus most of the effort in examining the recovered pieces is to get clues as to where the big stuff lies on the seabed. So I would suggest to devote more speculation, if any, to that end since we really need more hard data or we are just filling these pages with the same old rehash.

let's see how long this post lasts

SaturnV

19th Jun 2009, 13:57

GreatBear (post 1881), I think the June 16 position of the ships is centered on where the floating wreckage has drifted, which may be some distance from the area of impact.

The plot of the wreckage recovered June 6.

http://i136.photobucket.com/albums/q199/tahitiplage/SNAG-0288.jpg

The plot of the wreckage recovered on June 7.

http://i136.photobucket.com/albums/q199/tahitiplage/SNAG-0289.jpg

The plot of the recovery of the bodies, the last recovery (the 50th body I believe) being on June 16th, which is where the Brazilian Navy now has most of its recovery flotilla.

http://i136.photobucket.com/albums/q199/tahitiplage/SNAG-0287.jpg

The plots appear to show a north and then a west drift. The center of the search (as of June 16) is about where 145 [km] appears on the third chart.

Without an identifying coda or index, the numbering system lacks obvious coherence. Of note are items 9 and 11 near the bottom of the June 7 chart. Did these drift south or do these represent the first pieces of the plane to come off? (The square at the bottom of the frame in the charts for June 6 and 7 is the last reported position.)

Will Fraser

19th Jun 2009, 14:22

I certainly appreciate the focus on data, especially as it relates to Box/Pilot interface. My understanding of ACARS suggests to me a system that is designed not specifically to do what most folks here would like to see it do. It is not a streaming super computer. Its computing and tx formats are designed for a non-critical logging and storage of mx demands to be addressed later, at arrival.

Given the grand exposure to very limited evidence, the number and span if hypotheses is narrow. ACARS, pieces of debris, and an interesting record of possible precedent failures. Other than a short term at medical school, I am wholly unprepared and incompetent to consider the humanity as evidence.

A precedent record of pitot issues is a start, and what remains of the air data might be foundation for considering a high altitude high speed upset occurring at or near a/p disconnect. The parameters for reversion to hand control seem rather wide at M.80, (see PJ2 description of AltLaw), even with healthy pitots, the amount of control available to a surprised Command Pilot seems large. It is apparent with the evidence that at a/p disconnect, the roll control was a range of 60 degrees, albeit applied at a rate that wouldn't disagree with a/p limits, (load). This rate and range is what presents to me a potential for a very quick disconnect by an a/p that might have been doing a grand job, conveying no issues to the crew, but at a/s cue loss could be an enormous challenge to format change, autos to hand. Any roll or turbulence induced yaw or pitch excursions, without cues in a dark and flickering cockpit suddenly requiring hand control inputs may have begun a rapid upset. The VS was found virtually unblemished. The Rudder has a severe tear at its proximal swing with the aft fuselage, but remained fully and consistently attached to its mate.

A loss of the VS and Rudder as a result of the initial upset, some combination of yaw, pitch, and roll either coordinated or not may have begun the out of control descent. As the a/c would have been decelerating from its max. speed after upset, the remaining airframe would have been giving up its structure (in some unknown sequence) and created a cone of ballistic dependent debris on the Ocean's surface below. Deployed or not, the spoiler panel shows severe damage that suggests to me extreme aerodynamic loading, flutter and separation. The suggestion from its appearance is that similar loads occurred elsewhere on the a/c, enhancing the theory of an aerodynamically destructive descent. The debris collected is light and flat, with high area to mass ratio. It travelled more slowly through the air than heavier material, and most likely further.

Without a functional tail, the only other over water accident I am familiar with had the fuselage and wing structures descend immediately into the water in virtually a vertical and inverted entry, an MD-80.

I appreciate the technical nature of this thread. It is an extremely informative and enlightening enterprise.

Will Fraser

Hyperveloce

19th Jun 2009, 14:56

Some contributions state that the ADR and the IRU parts of the ADIRU are independant from each other, that you can switch off one of them to let the other operate in a normal way. This lead some contributors to say that a complete anemometric failure does not account for an IRU failure as reported by the ACARS messages.

But what do we learn from the Qantas incident ?

"An A330 aircraft experienced a sudden nose down order while in cruise. This order was preceded by an automatic autopilot disconnection and triggering of the “NAV IR1 FAULT” Electronic Centralised Aircraft Monitor (ECAM) Caution. Investigations highlighted that at time of the event the Air Data Reference 1 (ADR) part of ADIRU1 was providing erroneous and temporary wrong parameters in a random manner. This abnormal behaviour of the ADR1 led to several consequences such as unjustified stall and over speed warnings, loss of attitude information on Captain Primary Flight Display (PFD) and several ECAM warnings."
(source: http://atis.casa.go.kr/ASMS_AD/file/EASA%202008-0203-E.pdf )

is that to say that a faulty ADR can generate a "NAV IR1 FAULT" ?

in such a case, what is the procedure ? :

"Turn off the affected IR.
Turn off the corresponding ADR.
Use AIR DATA switching as appropriate.
Use ATT HDG switching as appropriate."

is that to say that when an ADR is faulty, the corresponding IR should be switched off ? (another directive acknowledges that a faling ADIRU can be difficult to switch off)

can we truely say that the ADR and the IRU parts are independant ?

And the ISIS can fail through its mach meter function.

Given these facts, a failure chain starting from a severe icing of the Pitots probes, statics ports and possibly barometric pressure sensors would seem relevant to explain the sequence of fault reports ?
Jeff

CONF iture

19th Jun 2009, 15:04

Till now, I was strongly convinced that the failure of all IR's were responsible for the crash.
Aguadalte, what makes you still strongly believe all IR's have either failed or been switched off ?

petermcleland

19th Jun 2009, 15:39

Ranamin...Quote:

http://www.atsb.gov.au/publications/...70_interim.pdf

In-flight upset
154 km west of Learmonth, WA
7 October 2008
VH-QPA
Airbus A330-303

Thanks for the pointer Ranamin. I found that report most interesting and was rather disturbed by the following statements in it:-

Scenario where AOA spikes could influence flight controls.

The aircraft manufacturer advised that the AOA processing algorithms would prevent most types of erroneous AOA inputs provided by the ADIRUs having an influence on flight control commands. This included situations such as an AOA ‘runaway’ (or a continuous divergence from the correct value), single AOA spikes and most situations where there were multiple AOA spikes. However, the manufacturer identified that, in a very specific situation, the PRIMs could generate an undesired nose-down elevator command. This specific situation involved multiple AOA data spikes with the following properties:
• there were at least two short duration, high amplitude spikes
• the first spike was shorter than 1 second
• the second spike occurred and was still present 1.2 seconds after the detection of the first spike.

Simulation studies.

As part of the investigation, the manufacturer reported that it had performed simulation studies concerning the filtering of AOA spikes by a PRIM. The simulation studies confirmed that the input of two AOA spikes which met the conditions listed above, were not effectively filtered by the PRIM, and could lead to undesired nose-down elevator commands. The aircraft manufacturer advised that the 10-degree elevator command associated with the first in-flight upset, was the result of 4 degrees of alpha prot and the 6 degree authority of the anti pitch-up compensation. The 10-degree command was close to the worst possible scenario that could arise from the design limitation in the AOA processing algorithm.

Relevance to other aircraft types.

The manufacturer advised that the AOA processing algorithms used by A330 aircraft were also used by A340 aircraft. However, different algorithms were in use on other Airbus types, which were reported to be more robust to AOA spikes. The manufacturer advised that AOA spikes matching the above scenario would not have caused a pitch-down event on Airbus aircraft other than an A330 or A340.

Mark in CA

19th Jun 2009, 15:55

Once again, The Onion, in its tasteless and irreverent style, comments on the media bloviators covering this accident:

Investigators Determine Air France Disaster Caused By Plane Crash | The Onion - America's Finest News Source (http://www.theonion.com/content/news/investigators_determine_air_france)

HarryMann

19th Jun 2009, 15:56

I am in agreement here that seeing the VS break off so cleanly is quite disturbing. I would love to see pics of other mfg's VS failures. It is much more preferred to see (as in the MD-11 crash you mentioned) that the critical pieces are robust.

Hardly cleanly, having pulled major structure out of the rear fuselage!

Seems its a matter of damned if you do & damned if you don't with some people - what do you really want a structure to do, play strip-poker or Russian roulette?

HarryMann

19th Jun 2009, 16:01

The Onion - quite tasteless reallly :rolleyes:

jmig29

19th Jun 2009, 16:01

Do we have proof the A/C lost ALT indications? Or just the Speed? Because Speed ind loss will not afect Alt indication. On the other hand, Alt ind loss would alter the speed. Plus, the Speed (pitot) sensor is more prone to weather influence (dynamics) than Static (vacuum actuation and flushed) sensors. Any problem in any of these sensors would fail the ADR part of ADIRU. And in fact ALL we know is that an ADIRU reported faulty in the IR part (#2), as well as an ADR DYSAGREE, which can be due to Alt, Spd, or both.Just because we discuss many scenarios does not necessarily make it true, unless YOU'RE THERE!Looks like an established fact that speed sensors caused it (by reading most of the threads in this Forum), and what is most strange is the lack of self-defense from AIRBUS part on the subject.We should all show a bit more respect for the families involved, the professionals involved, and WAIT FOR THE INVESTIGATION TO FINISH!But I have to keep stopping myself to come here, this was just a reminder!

capeverde2008

19th Jun 2009, 16:02

Quote - "NO COMMERCIAL AIRCRAFT SHOULD GO WITHIN 100nm LATERALLY of CB - ICTZ (Tropical Cumulo-Nimbus clouds) activity.....for any reason...FULL STOP. NEVER, EVER, don't even think about it.... or trying to overfly it. That is from MANY years experience and many grey hairs of wisdom!!"

"I guess you never fly through Texas with thunderstorms as big then. You would have to deviate over Oklahoma with those parameters." p51guy quote

Yes, T-storms big enough to power Africa for a few days!
Yes, deviate over Oklahoma, whole of Central Africa if necessary! Fuel divertion, turn back....it really is 'lives' at stake. Plan well, be cautious and arrive alive....

Rgds, capeverde2008 :ugh: :}

augustusjeremy

19th Jun 2009, 16:02

The answer is NO. ADIRU= AD+IRU
Actually 2 boxes in one. The IRU part works seperately from the ADR Part. U can switch off the ADR part , but when U switch off the IRU, the box is switched off.I suppose it means that the ADR part of ADIRU needs the corresponding IRU but the corresponding IRU wouldn't need the ADR, which could prove my point that faulty ADR (airspeed) data would not generate IR related faults.

In the qantas flight maybe the IR1 problems led to erroneous ADR1 "conclusions", including AOA (please correct me if wrong).

Another question:

Could someone already "decipher" the TCAS fault... How does it relate to "doppler", if it really does ? Is it related to the "antenna" or to distance/speed calculation (then it would need at least ground speed, I suppose).

Editing: Someone already stated that in the AI docs the TCAS is indeed 34-43 and not "doppler"

24victor

19th Jun 2009, 16:04

Without a functional tail, the only other over water accident I am familiar with had the fuselage and wing structures descend immediately into the water in virtually a vertical and inverted entry, an MD-80.

Alaskan 261 lost trim control of the horizontal stab not the vertical fin causing a severe and unrecoverable nose-down pitch.:(

24V

deSitter

19th Jun 2009, 16:18

Harry Mann - "pulled structure out!!"

No, it failed cleanly and very suddenly - this is shown by the damage to the lower rudder which nevertheless remained attached to the VS implying it was levered backward against the tail cone and shattered under sudden longitudinal compression. This in turn implies that the forward attachment failed very suddenly and explosively, the way composites do, and you can see this in the exposed cross-hatch "brushy" damage in the VS internal structure (seen from below).

I still believe that either the VS failed on its own in turbulence, or as a result of a lightning strike traveling down the aluminum fuselage and exiting at the VS front root, destroying structure there. The latter is more consistent with subsequent computer systems failures.

-drl

VicMel

19th Jun 2009, 16:28

I have been involved with the design and integration of the software on a number of avionic embedded systems; from a Fault Detection, Recovery and Reporting perspective I have some observations and some questions.
1. Only reporting 'own' failures to ACARS: IIRC on A320 there was an Airbus requirement on avionic systems that they had to have a 90% confidence level for detecting and reporting an internal failure, down to 'sub-system' level. In order to avoid a 'cascade' of messages, it is obviously important not to generate a maintenance message when the fault is known to be external to that particular system. This is possibly significance with the the IR2 message and the TCAS FAULT message; these should not have been generated because of an external ADR problem, but because of internally detected faults. A question for an ISIS expert, would high 'g' loads cause an ISIS system to consider that outputs from its gyros or accelerometers were 'out of spec'? A question for a TCAS expert, what would cause TCAS to generate an ACARS message, a GPS derived value (such as speed or rate of change of heading) out of spec? An earlier post referred to TCAS using Doppler to determine relative speed between aircraft; would 'unbelievable' changes in relative speed cause an internal fault to be flagged?
2. Delay on ACARS messages: Once an Airbus avionic system detects a fault it should immediately mark its outputs as Invalid/Unavailable to its 'users' (including CFDS). However, there may be a significant delay before the system can determine if this fault is a 'hard' internal failure. Its recovery process might include retrying an input a number of times, resets (of sub-elements of the system, or the complete system) or diagnostics (such as running loop-back tests on the ARINC 429 Input Port). So depending on the type of detected fault there might be a significant delay before a system is confident in reporting a failure. For example, the loss of an external communication link for a minute or so may not be considered a 'hard' failure, loss for 10 minutes or so might be.
3. Timing sequence of ACARS messages: As pointed out in other posts, ACARS primary purpose is to provide maintenance data to Ground Crew. There is no particular urgency to providing maintenance data to the ground (as opposed to ASAP for fault information to the flight crew). As it is an inefficient use of processing power to provide data at a rate faster than it is needed, an aircraft system could be designed to schedule a task every couple of minutes to check the system's internal fault log to see if a maintenance message should be composed and sent to ACARS. So the sequence on messages generated by different systems could be quite random.
4. Failures unlikely to be caused by lightning: It is unlikely that any of the ACARS failure messages were due to damage by lightning as it is likely that the system's vulnerable processing capability (CPU, RAM, etc.) would also have been affected to such an extent that the system would not be able to compose and send any messages to the ACARS. It is an important 'fact' that the reporting systems are still running; the failure they are reporting is unlikely to be due to lightning, power supply loss, fire or being shaken to destruction.
5. Setting fault detection levels: Avionic system designers are well aware of the difficulties in getting the right balance between 'nuisance false fault reports' and 'not detecting marginal faults'. The limits within the software that are used to flag a fault on sensor input values (max/min, rate of change, comparison) are based on the 'expected' range of values during aircraft operation; persistent input values that are outside the aircraft's operational limits should be considered as more likely to be an internal fault and hence flagged as such. A system that flags itself as failed and needing maintenance might in fact be working, it is just that what its sensors are telling it is 'unbelievable'!

lomapaseo

19th Jun 2009, 16:35

Harry Mann - "pulled structure out!!"

No, it failed cleanly and very suddenly - this is shown by the damage to the lower rudder which nevertheless remained attached to the VS implying it was levered backward against the tail cone and shattered under sudden longitudinal compression. This in turn implies that the forward attachment failed very suddenly and explosively, the way composites do, and you can see this in the exposed cross-hatch "brushy" damage in the VS internal structure (seen from below).

:=

As always there is the chicken and the egg as to what happened first. I would caution against presuming the composite VS failed first just by looking at the available photos.

ACLS65

19th Jun 2009, 17:12

I have been trying to work back from the ACARS msgs to what you would see in the cockpit and what the normal responses would be.

If anyone else is interested this seems to be a decent reference.

SmartCockpit - Airbus 330 (http://www.smartcockpit.com/plane/airbus/A330/)

GreatBear

19th Jun 2009, 17:13

Curiously, only the thinnest information about the search and recovery effort for the the AF447 FDR/CVR and hull has been disseminated to the public. With the French BEA tasked to lead the investigation under ICAO rules for incidents occurring in international airspace/waters, a hugely expensive joint effort has been orchestrated using assets and expertise from France, Brazil, United Kingdom, United States, and Holland. The Brazilians have been providing imagery and consistent daily updates about the recovery effort for debris and remains found on the surface (http://www.fab.mil.br/portal/voo447/) and BEA are providing occasional press releases (News (http://www.bea.aero/anglaise/actualite/actu.htm)) including a "Sea Search Operations" summary document created on 17/06/09 (http://www.bea.aero/anglaise/actualite/af447/sea.search.ops.pdf).

But the granularity of official data is remarkably bland, hardly even suitable for media infographics and newsbites and certainly inadequate for reasoned analysis: never a lat/long reference; never a note about hull search areas and sensor towing depths; never a factual description of the ACARS "maintenance messages."

Officially "validated" facts on 17/06/09 per BEA (News (http://www.bea.aero/anglaise/actualite/actu.htm)):

# The airplane was in cruise at flight level 350 (about 10,500 metres).

# No messages indicating problems were received on the air traffic control radio frequencies.

# Close to the planned route of the airplane above the Atlantic there were significant convective cells characteristic of the equatorial regions;

# The last position message from the airplane was broadcast by the ACARS automatic system at 2 h 10 UTC.

# Between 2 h 10 and 2 h 14 UTC, 24 maintenance messages were transmitted by the ACARS, including 14 between 2 h 10 and 2 h 11.

# Analysis of these messages shows inconsistencies between the various speeds measured. Most of the messages appear to result from these inconsistencies; they correspond to the loss of several flight assistance systems.

That's it! The official sum of "validated" information on 17/06/09. Thin. At every opportunity, BEA cautions "avoid any hasty interpretation or speculation".

With such thin data, what else is there but speculation?

On the upside, what this and the Techno AF447 PPruNe threads have proven is that details can be flushed from the most fuzzy material. And all the speculation offered on these threads is, indeed, REALLY valuable, from possible meteor strikes (glowing dots reported on the sea surface) to faulty AOA processing algorithms. To finally solve this puzzle and generate credible answers about why this event occurred, ALL these speculations will be "weighted" and fed into an equation, where they will end up being ignored or adding value to a solution. Most commendable to this thread's participants, in almost 2000 posts there has been little interest in blame, simply a driving need to know what happened to upset this aircraft. That's being professional.

deSitter

19th Jun 2009, 17:38

GreatBear,

Very well said. All accident investigation is really gradually more informed speculation until this gets converted into hard facts, unless the cause is immediately apparent (rare). There is nothing wrong with reasoned speculation unless it makes one blind to contradictory evidence.

-drl

aguadalte

19th Jun 2009, 18:21

RED OEB – RED OEB – RED OEB – RED OEB – RED OEB – RED OEB – RED OEB
Issued by STL
File in FCOM Vol 3
OEB N°: 74/4 DEC 08
Associated with QRH OEB PROC N°: 74/4
- This OEB covers a significant operational issue. Non-compliance with this OEB should have a significant impact on the safe operations of the aircraft. The Operators shall distribute its content to all flight crews without delay. An extract of this OEB is provided for insertion in the QRH.
- It is strongly recommended that all Operators accelerate the incorporation of all corrective Service Bulletins as soon as they are available.
SUBJECT:
IR FAILURE OR ATT FLAG ON PFD
APPLICABLE TO:
All A330 aircraft fitted with NORTHROP GRUMMAN - LITTON ADIRU
CANCELLED BY:
TBD
R
REASON FOR ISSUE 4:
RRRR
The previous OEB revision requested to de-energize the affected ADIRU if the IR and/or ADR OFF lights did not illuminate. The OEB procedure is now revised in order to recommend that the IR mode rotary selector be set to OFF in all cases in order to address all identified failure cases.
Page 1 of 5
Operations Engineering Bulletins are issued by Airbus as the need arises to quickly transmit technical and procedural information. They are distributed to all FCOM holders and to others who need advice of changes to operational information.
Information in this bulletin is recommended by Airbus but may not be approved by Airworthiness Authorities.
If the procedures contained in this OEB differ from the procedures in the AFM, the AFM remains the reference.
OEB N° Page 2 of 5
74/4
REASON FOR ISSUE:
This OEB is issued in order to provide a procedure enabling to mitigate the probability of occurrence of a sudden nose down order.
EXPLANATION:
An A330 aircraft experienced a sudden nose down order during cruise. This order was preceded by an automatic autopilot disconnection and triggering of the NAV IR 1 FAULT ECAM caution.
Investigations highlighted that at the moment of the event the ADR 1 was providing erroneous and temporary wrong parameters in a random manner. This abnormal behavior of the ADR 1 led to several consequences such as unjustified stall and over speed warnings, loss of attitude information on the Primary Flight Display, several ECAM warnings.
Among the abnormal parameters, the provided Angle of Attack value was such that the flight control computers commanded nose down movement.
The aim of the following procedure is to isolate both the IR and ADR when an IR is detected faulty in order to prevent the ADR from providing erroneous data to other aircraft systems.
TO BE CONTINUED ON NEXT PAGE
PROCEDURE:
RRRR
OEB N° Page 3 of 5
74/4
RRRR
• If all ADIRU operative before failure:
If one IR is self detected faulty or if the ATT red flag is displayed on the Captain or First Officer PFD, the affected IR and the corresponding ADR must be disconnected.
NAV IR 1(2)(3) FAULT, or ATT flag displayed on CAPT (F/O) PFD
-IR (affected) pb …………………………..…… OFF
The affected IR is the one self-detected faulty or supplying the PFD displaying the ATT red Flag.
The OFF light may not illuminate
-ADR (corresponding) pb ………..………...… OFF
ADR 1 corresponds to IR 1.
ADR 2 corresponds to IR 2.
ADR 3 corresponds to IR 3.
The OFF light may not illuminate
-IR (affected) MODE rotary selector ……….. OFF
The IR mode rotary selector is set to OFF in order to de-energize the ADIRU. The OFF lights of the IR and ADR pushbutton will go off.
Setting the IR mode rotary selector to OFF is an irreversible action. Therefore, both PF and PNF must clearly identify the corresponding selector before setting it to OFF.
• If IR 1(2) affected:
In order to prevent possible failure of ADIRU 3, the flight crew must switch the AIR DATA and the ATT HDG in the following order:
-AIR DATA SWTG …........………..……... CAPT (F/O) ON 3
-ATT HDG SWTG ..…….......…………….. CAPT (F/O) ON 3
TO BE CONTINUED ON NEXT PAGE
CAUTION
RRRRR RRRR
• If one ADIRU already disconnected before failure:
In case of dispatch with one ADIRU under MMEL or one ADIRU already disconnected in flight, and an IR failure occurs, either detected by an IR 1+2 (1+3)(2+3) FAULT or with ATT red flag displayed on CAPT or F/O PFD, the affected IR and the corresponding ADR must be disconnected.
NAV IR 1+2(1+3)(2+3) FAULT, or ATT flag displayed on CAPT (F/O) PFD
-IR (affected) pb ………………..…….…...…… OFF
The affected IR is the one self-detected faulty or supplying the PFD displaying the ATT red Flag.
The OFF light may not illuminate
-ADR (corresponding) pb ……………...…….. OFF
ADR 1 corresponds to IR 1.
ADR 2 corresponds to IR 2.
ADR 3 corresponds to IR 3.
The OFF light may not illuminate
-IR (affected) MODE rotary selector ……….. OFF
The IR mode rotary selector is set to OFF in order to de-energize the ADIRU. The OFF lights of the IR and ADR pushbutton will go off.
Setting the IR mode rotary selector to OFF is an irreversible action. Therefore, both PF and PNF must clearly identify the corresponding selector before setting it to OFF.
CAUTION
• If IR 1+2 affected:
In order to prevent possible failure of ADIRU 3, the flight crew must switch the AIR DATA and the ATT HDG in the following order:
-AIR DATA SWTG ..........………………….CAPT ON 3
-ATT HDG SWTG .......………...…..………CAPT ON 3
Note: First officer can recover IR information, by using the EFIS DMC selector (copy of the opposite side).
SPD BRK ………………………………….…….. DO NOT USE
• IF CG AFT 32%:
-T TANK MODE………………….……….. FWD
F/CTL ALTN LAW (PROT LOST)
MAX SPEED ………………………..………..…. 330/.82
OEB N° Page 4 of 5
74/4
OEB N° Page 5 of 5
74/4
OEB REMINDER:
On aircraft that have the OEB reminder function, the procedures of NAV IR 1(2)(3) and NAV IR 1+2(1+3)(2+3) FAULT ECAM cautions may be flagged.
The “refer to QRH PROC” line will then be displayed instead of the procedure itself.
To flag those procedures, the following codes should be entered in the FWC OEB database.
Code WARN STS
NAV IR 1 FAULT YES NO
34/10/050/061
NAV IR 2 FAULT YES NO
34/10/060/063
NAV IR 3 FAULT YES NO
34/10/070/065
NAV IR 1+2 FAULT YES NO
34/10/020/055
NAV IR 1+3 FAULT YES NO
34/10/030/057
NAV IR 2+3 FAULT YES NO
34/10/040/059
CORRECTIVE ACTION:
Under investigation
Note: The interchangeability code, given in the Illustrated Part Catalog (IPC), indicates the conditions for interchangeability of equipment. After installation of corrective modification(s)/SB(s), if an Operator reinstalls any equipment affected by this OEB it is the Operator's responsibility to ensure that the recommendations given in this OEB are applied again for the applicable aircraft.

crisb

19th Jun 2009, 18:44

More pics up on the Brazil Military site .. also wondered what this box / container was and are those bits of structure sticking into it?

http://www.fab.mil.br/portal/voo447/FOTOS/190609/site/foto_2.jpg

http://www.fab.mil.br/portal/voo447/FOTOS/190609/site/foto_1.jpg

augustusjeremy

19th Jun 2009, 18:50

It is really not clear that all pitots were disagreeing (at least from what we have - maybe the ACARS message line was cut to be printed).

From the A330 TroubleShooting Manual:
Source EFCS2 Class : 1 HARD
Identifiers : EFCS1,AFS
341115 - PROBE-PITOT 1+2 / 2+3 / 1+3 (9DA)
Le TSM (Trouble Shooting Manual) utilisé il y a deux jours indique :

34-11-15 EFCS2 : TASK 27-91-00-810-822
Disagree of the Pitot Probe Data in the FCPCs
1. Possible Causes

pitot probe 2. Job Set-up Information
A. Referenced Information
AMM 34-11-15-000-801 Removal of the Pitot Probe (9DA1, 9DA2, 9DA3)
AMM 34-11-15-200-801 Inspection/Check of the Pitot Probe (9DA1, 9DA2, 9DA3)
AMM 34-11-15-400-801 Installation of the Pitot Probe (9DA1, 9DA2, 9DA3) 3. Fault Confirmation
A. Test
(1)Not applicable, you cannot confirm this fault on the ground. 4. Fault Isolation
A. If the crew made a report that the F/CTL ALTN LAW or F/CTL DIRECT LAW warning was shown on the EWD for some seconds only:
- no trouble shooting is necessary.
B. If the F/CTL ALTN LAW or F/CTL DIRECT LAW warning is shown and stays on during the flight:
(1)Do the inspection of the pitot probe (9DA1, 9DA2, 9DA3)
AMM TASK 34-11-15-200-801
replace the defective pitot probe (9DA1 or 9DA2 or 9DA3)
AMM TASK 34-11-15-000-801 and AMM TASK 34-11-15-400-801

jeremiahrex

19th Jun 2009, 18:52

As stated earlier, the difference between a mechanical gyroscope (spinning bicycle wheel on gimbals) and a laser ring gyro is significant. However, don't overstate this. Laser ring gyros are significantly superior to mechanical gyros in every way. They have drift specs that far exceed the best mechanical gyros, are smaller, lighter and more robust than any mechanical gyro. They can be sampled faster (1000 deg/s, 3000 deg/s^2) and combined with high quality accelerometers allows you to integrate to find your attitude.

The downsides of mechanical gyros far exceed their utility. They have inferior drift specs (friction sucks) and they're far less reliable. Just because something is old and mechnical doesn't mean it's better...

augustusjeremy

19th Jun 2009, 19:04

It seems the ISIS fault refers to anemometric problem. Then it could relate to total/static pressure sensors.

From a french site:

Eurocockpit - Accueil (http://www.eurocockpit.com/)

Afin de clore le précédent article, nous pouvons donc affirmer aujourd'hui, au vu de l'intégralité des messages de fautes, les origines des pannes. Par exemple :

34 2200 - ISIS (22FN-10FC) SPEED OR MACH FUNCTION (Source ISIS Class 1 HARD) montre que -comme annoncé- on avait raison de s'attendre à un problème anémométrique.

From the same site, however:

Ce qui semble étonner est le FLR venant de l’IR2 qui n’est normalement pas affectée par les informations barométriques, puisqu'il s'agit d'une source inertielle gyrolaser et qui ne dépend pas de l'Air Data Reference (ADR)..

Basically saying that the IR2 fault/disagree wouldn't be affected by air data inputs.

PJ2

19th Jun 2009, 19:12

what is that stuff?
The large item is likely the other (back) side of the galley we see being recovered, (without all it's bins in place). Notice the support structure on what is likely the bottom of the galley installation, punctured upwards and to the galley's right, (we don't know which way this structure was installed in the aircraft so we don't know if the support structure is bent to starboard or port).

Second photo:
- We see a long section of the overhead bin support structure in the middle of the photo.
- a flourescent yellow/green box similar to the orange one seen in earlier photos - perhaps the defibrilator - or not.
- another part-bulkhead structure similar to the one recovered which had the F/A's seats; one can see a mounting structure which may have held a fire extinguisher.
- cabin interior structure, with windows
- an Oxygen bottle (green bottle, lower center-left
- sections which appear to be the bottoms of ULD's, (unit-load-cargo devices), although they appear in pretty good shape given their relatively light structure
- a large section of a flight control - hard to say which one
- galley bins, (top right)

augustusjeremy

19th Jun 2009, 19:27

Gents,

Could one of you inform me whether the raw airspeed data fed to EFCS2(?) in order to detect faulty pitots comes from the ADIRUS or directly from the ADMs ?

If it comes from the ADIRUs, maybe we already have a decent explanation for almost all those ACARS messages.

Smithm

19th Jun 2009, 19:38

I have followed this thread as much as possible and understandably much is quite technical but I have a simple question, can bad weather alone bring down a modern airliner?

I just a member of the public interested in aviation and have been under the impression for years that there is no turbulence that could bring down modern aircraft at cruising height. Am I being naive?

Apologies if this question is a bit 'aviation for the under 5's':bored:

Pontius Navigator

19th Jun 2009, 19:41

simple question, can bad weather alone bring down a modern airliner?

Yes, although weather usually needs some human assistance, like driving the plane into the weather.

PS

Falconer, by refering to modern I think he accepted that earlier aircraft were susceptible to weather. By modern he was hoping that 'weather' had been removed as a risk.

falconer1

19th Jun 2009, 19:46

and no, Smithm, no apology needed here..

I have followed this thread as much as possible and understandably much is quite technical but I have a simple question, can bad weather alone bring down a modern airliner?

Absolutely, YES..

and modern or not does not have anything to do with it..

EVERY plane can be flown into a weather situation that will break it..

weather has always and will always be a prime factor

unfortunately it is us, in the industry, that need to remind ourselves of these facts... sometimes they seem to be forgotten..

Graybeard

19th Jun 2009, 20:28

The world's largest distributor of used aircraft parts:
Thunderstoms.

deSitter

19th Jun 2009, 20:48

PJ2,

Thanks for that info - the control surface seems to be an airfoil, perhaps part of an elevator panel? The HS itself is too big I think for the debris to be part of that. Any information that leads to identifying that piece of debris would be very interesting.

Here is a good view of the underside of the HS/elevator

http://www.samchuiphotos.com/QFnew/DSC_5440.jpg

Edit: the notch in one side of the unknown control surface part shown among the debris could very well be a hinge recess for the elevator panel.

-drl

Hyperveloce

19th Jun 2009, 20:52

Trying to understand how a faulty ADR can generate a NAV IR fault report (Qantas), how it can contaminate the automated systems without being detected/cross checked as an outlier (although there are two other valid measures):
The QANTAS Airbus A330 Inflight upsets (http://www.iasa-intl.com/folders/belfast/ADIRU_faults&Tolerances-2.htm)
maybe of interest. There were two different cases for Qantas. This risk was also present with the Boeing777 (FAA emergency AD 2005-18-51)

A contributor with a professional experience in avionics failure modes raised the possibility that the IRU declared itself as faulty as it was measuring (true) accelerations or rotations known as outside from the normal flight enveloppe.
Jeff

mercurydancer

19th Jun 2009, 20:53

Thank you.

From the deck photograph and the side view it does indeed seem to be the defibrillator container. I'm surprised it floated as those things are very heavy.

RatherBeFlying

19th Jun 2009, 21:00

Two possible explanations come to mind:
AF447 was significantly off track dodging CBs when it ran into trouble. Now that the search has broadened to include the actual track including subsequent drift, debris is turning up.
The buoyant pieces worked loose under water and floated up some days later -- a lesser probability.

overthewing

19th Jun 2009, 21:07

I think this picture shows that PJ2 was right about the large object being the back side of the galley structure.

http://www.fab.mil.br/portal/voo447/FOTOS/190609/site/foto_8.jpg

mercurydancer

19th Jun 2009, 21:15

Largely its conjecture but I would have thought that what stays bouyant remains that way until its physical state changes, it gets saturated or breaks up and cannot displace its own mass in water.

If something does sink then then there arent many factors that can make it float again. Studies of the big ships which have sank (Bismarck in particular) indicate that what goes down stays down.

SaturnV

19th Jun 2009, 21:59

I doubt that parts are breaking free from the airplane and floating to the surface. Within the general search zone, the minimum depth is 864 meters, the maximum depth is 4606 meters.

Pressure increases in the ocean at roughly one atmosphere for every ten meters of depth. What made a section of the plane buoyant at the surface would likely be crushed at the depths this plane is now lying at. I doubt that honeycomb structures are designed to withstand hundreds of bars of pressure.

DorianB

19th Jun 2009, 22:04

Many new photos archived here:

AF447 Photo Archive (http://photobucket.com/af447)

http://i635.photobucket.com/albums/uu79/DorianBanks/th_296dab21-b365-4d8f-bf63-0fdf469a0c7.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=296dab21-b365-4d8f-bf63-0fdf469a0c7.jpg)

http://i635.photobucket.com/albums/uu79/DorianBanks/th_DSC00713.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=DSC00713.jpg)

http://i635.photobucket.com/albums/uu79/DorianBanks/th_caboclo_nova2.jpg (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=caboclo_nova2.jpg)

dicksorchard

19th Jun 2009, 22:37

Autopsies Suggest Airbus Passengers Were Seated, Estado Says - Bloomberg.com (http://www.bloomberg.com/apps/news?pid=20601087&sid=aCX7YbZZwokM)

Autopsies Suggest Airbus Passengers Were Seated, Estado Says

By Laura Price
June 17 (Bloomberg) -- The injuries to many of the bodies recovered after the June 1 crash of an Air France plane suggest they were seated at the time of impact, indicating at least one section of fuselage may have hit the ocean on its underbelly, O Estado de S. Paulo said, citing unidentified investigators.
Autopsies showed a majority of the 43 bodies examined so far had leg and hip fractures typical of a trauma suffered while sitting, the Brazilian newspaper said. The lack of many skull injuries in the passengers on the Rio de Janeiro-to-Paris flight also suggests the Airbus A330-200 didn’t nosedive, Estado said.
An official from the Legal Medical Institute in the Brazilian city of Recife declined to comment today in a telephone interview, saying official information hasn’t yet been published.
Air France Flight 447 carried 228 passengers and crew members. Fifty bodies have been recovered from the Atlantic Ocean.

Triskel

19th Jun 2009, 22:50

Re-discussions about sunken debris - as someone else said, a battleship would cetainly sink but after the 1979 Fastnet disaster most of the GRP hulls were found 'floating' around 10 metres below the surface (where compression equalised the density of the material with the water). Since this a/c was largely composites there are probably bits 'floating' at many levels of the ocean.

HarryMann

19th Jun 2009, 22:56

The containers have obviously been removed once on board the search vessel. Is it not de-rigeur to leave such items as complete and untouched as possible post recovery?

== Debris distribution ==

Something not asked so far... viz debris distribution. If (and only if) a cruise alt. breakup occurred (ejecting much of what has been found), then...

Having mulled over what sort of distances lighter debris might be spread over falling from 35,000 ft, using 'back of fag packet' sums, something like 5 to 10 miles might be the maximum to be expected, making a few (scary but not too extreme) estimates of thermal updraft and winds aloft.

Thus if two (light) items travelled in opposite directions, as a first stab, one wouldn't expect them to be more than 10 to 20 miles apart..

Happy to be shot down, but I rather like 'some' numbers to work with, rather than none...

Will Fraser

19th Jun 2009, 23:11

Would anyone know the location when found of the elevator bit? (if it proves to be so). If near the VS' position when found, that would suggest a loss of more tailfeathers at upset than just the fin/rudder. The forward VS at the root is so very close to the aft pressure bulkhead, if it separated and disrupted the aft fuselage structure including the HS attach roots, the entire tail portion would have been involved, perhaps (perhaps) failing the entire tail to include a full cross section of the aft cabin. The 'cabin pres.' cue would have followed.

quaeler

19th Jun 2009, 23:25

The last photo in the new update ( caboclo_nova2.jpg picture by DorianBanks - Photobucket (http://s635.photobucket.com/albums/uu79/DorianBanks/?action=view&current=caboclo_nova2.jpg) ) shows the overhead baggage stow facade listing seats 42 K, J.

Parahelio

19th Jun 2009, 23:39

I say the right decision was to remove the aluminum containers from the galley before lifting it on board, the containers probably contained sea water and the added weight when netting the galley in would have deeply gouged the composite structure as it doesn’t have lifting points on it and is already severely weekend by impact. Plenty of photos of the position of the containers positions were most likely taken and there is no excuse for breaking a big peace like this by lifting it waterlogged.

The photographs are exalent, I have worked with composite building and repair on ultra light sailboats, other marine craft, airplanes and high speed “bullet” trains, and with the trains especially I have been involved in recovery and analysis of aluminum and composite debris after a mass transit accidents, very interesting photographs.

lomapaseo

20th Jun 2009, 01:41

The latest photos (today's) appear to show the floating debris from the large section fuselage splats with the ocean. this to me suggests that the drift from this material is current and wave borne from where the major sunken debris field is.

How much came off separately in the air is unknown (to me) but I agree that some of the pieces shown earlier (crew rest etc.) likely were shed before the fuselage hit the water.

To me nothing new and revealing, just a confirmation in some evidence that it broke up in the air and came down in large sections of fuselage and small pieces from inside the fuselage. Then the rest probably disgorged itself mostly upward as the big pieces hit the water. The question remains why.

PJ2

20th Jun 2009, 01:47

deSitter;
The HS itself is too big I think for the debris to be part of that.Yes, agree.
Will Fraser;
What we might be looking at is the outermost and underside tip of the port elevator. Unfamiliar with that area of this a/c,
If pressed, I'd say aileron but who knows at this moment? It's about an oxygen-bottle's width - I think the elevator is much larger but when you're walking around it, everything is large! :), however, in planform view in the AOM, the elevators are at least 3x the size of the ailerons.

What we can say is, it IS a flight control surface, (but most certainly not part of the horizontal stab box, which is metal, not honeycomb structure).

We have also in the photographs thanks to DorianB, a clear photo of two separate rows of overhead panels which would be situated above the passenger seats, containing the reading lights, seatbelt/no smoke signs and, as can be seen, the O2 masks.

Not sure where the First Aid container (flat door, pull-up latch box-like structure) is located but it would be in/near the F/A's area of work. The overhead bin indicating a green cross is where the First Aid/Doctor's kit/Defibrilator or possibly an extra oxygen bottle for F/As to walk about the cabin with, is stored.

Someone here made the observation that the elongated, more robust-looking structure at the bottom right in the photo of the collected wreckage looks like a "canoe", (which covers the flap tracks). I think that's possible. I am left wondering if the door which is part of the structure is the RAT door. I've seen it deployed on the ground, (during troubleshooting, we deployed it on the request of maintenance) and that's what the door looks like but obviously I have to qualify that - the piece is buried beneath a lot of other wreckage.

I don't think the items that look like ULD's, are in fact ULDs. ULDs are a thing honeycomb structure and covered with an aluminum surface. These appear to be almost as thick as the bulkhead structures. They're not big enough, either. Part of the cabin - not sure where?

Something to keep in the back of our minds is, we don't know in which order these photographs are and so cannot attribute their time stamp with the order of discovery at sea. We already know that the galley was found on June 07th but the photos we see of it here didnt' show up until the 17th.

lomapaseo;

Agree - nothing new but a confirmation of an in-flight breakup or, (in my view far less likely), a "low speed ditching" as opposed to a high-speed impact with the water. Due increased time during "descent" and assuming messages were generated after 02:14:59 and communications were working, we'd possibly have more ACARS messages, for one thing.

At what altitude and in what sequence the breakup occurred, we do not know.

vapilot2004

20th Jun 2009, 01:51

I have a very simple question and I've reviewed virtually all of the posts in both threads and not found an answer.

Of the pilots' flight instrument displays, what do they lose if all 3 pitot sources fail? Do they lose everything including bank, turn and vertical airspeed or do they just lose the airspeed display?

Grumpyoldgeek:
Airspeed.

Bank & Turn rely on IRU ATT data, basically gyros.
Vertical Speed & Altitude readouts come from the Static port data via the Air Data computers.

In my opinion, the pitot would be the most likely lost sensor set. The static ports are not facing the airstream and would not collect ice particles.

lomapaseo

20th Jun 2009, 02:03

PJ2

Yes I think that it is a canoe from a wing (significant only if it confirms the wings were still attached when it hit the water) therefore a much denser debris field.

I don't see any signs of water hydraulics on this stuff in the longitudnal direction thus I suspect it hit mostly flat protected by the pressure vessel which took the brunt of the water impact. Also good news for the search effort.

my fingers are crossed that they will at least find something dense on the ocean bottom besides an orange box or two with a pinger.

PJ2

20th Jun 2009, 02:12

lomapaseo;
I don't see any signs of water hydraulics on this stuff in the longitudnal direction thus I suspect it hit mostly flat protected by the pressure vessel which took the brunt of the water impact. Also good news for the search effort.

my fingers are crossed that they will at least find something dense on the ocean bottom besides an orange box or two with a pinger.
Yes, agree, very little evidence of distortion - more blunt-force breakage. Re "something dense", yes that is a good thing even if the recorders aren't found soon - they may be with the main wreckage, depending upon what happened to the tail-section.

Rollingthunder

20th Jun 2009, 03:59

ULDs are a thing honeycomb structure and covered with an aluminum surface.

Most ULDs are straight aluminium.

PJ2

20th Jun 2009, 04:04

rollingthunder - yeah, thanks, now that I think about it and recall, you're right - in any case I don't think the structures I pointed out are ULDs...too "beefy".

YRP

20th Jun 2009, 04:13

safetypee/h3dxb:

Can you establish what the purpose of the temperature sensors is, and if these are internal to ISIS or require an external temperature input.

The temperature probes would be used to improve the accuracy.

Electronic sensors like the accelerometers and rotation sensors in the ISIS often have a slight temperature sensitivity. For the same actual acceleration, the sensor may read slightly higher or lower based on the temperature - few percent maybe. The effect can be characterized quite accurately (sometimes done for each individual part). Then by measuring the temperature of the sensor, the software can compensate for it.

The temperature sensors would be measuring the temp of the sensor chips within the ISIS box, not an external or ambient temp.

ELAC

20th Jun 2009, 04:38

If pressed, I'd say aileron but who knows at this moment? It's about an oxygen-bottle's width - I think the elevator is much larger but when you're walking around it, everything is large! , however, in planform view in the AOM, the elevators are at least 3x the size of the ailerons.

What we can say is, it IS a flight control surface, (but most certainly not part of the horizontal stab box, which is metal, not honeycomb structure).

Yes I think that it is a canoe from a wing (significant only if it confirms the wings were still attached when it hit the water) therefore a much denser debris field.

PJ2, lomapaseo,

With a reasonable degree of certainty I would identify the piece of flight control surface wreckage as being a portion of the wing leading edge that normally lies beneath a leading edge slat. The small notch is the point at which an actuator rod extends through from the slat drive to the slat. In fact, a close look at the photo suggests that a part of the actuator rod is still present within the notch. Notches of this sort do not exist on the alierons, flaps, horizontal stabs or elevators, at least not that I've ever seen.

From the camber and rivet configuration my guess is that this piece came from the upper side fairly close to the wing tip. A bit of supporting evidence for this supposition is the grease mark on the rear portion of the section. This sort of mark is usually found on components nearby lubrication points, in this case probably a slat track that would have been located to one side or the other of the piece recovered.

ELAC