Tech Log The very best in practical technical discussion on the web

AF447

Old 17th Jun 2009, 04:42
  #1761 (permalink)  
 
Join Date: Dec 2003
Location: Gone from the FL sun to the desert Oasis
Age: 60
Posts: 199
Likes: 0
Received 0 Likes on 0 Posts
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?
Sleeping Freight Dog is offline  
Old 17th Jun 2009, 05:18
  #1762 (permalink)  
ZFT
N4790P
 
Join Date: Jun 2002
Location: Asia
Age: 73
Posts: 2,265
Received 10 Likes on 4 Posts
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?
ZFT is online now  
Old 17th Jun 2009, 05:21
  #1763 (permalink)  
jrv
 
Join Date: Jun 2009
Location: Austin, TX
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
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.
jrv is offline  
Old 17th Jun 2009, 05:39
  #1764 (permalink)  
 
Join Date: Jun 2009
Location: Somewhere out there
Age: 38
Posts: 65
Likes: 0
Received 0 Likes on 0 Posts
to speculate a little bit more

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
augustusjeremy is offline  
Old 17th Jun 2009, 05:57
  #1765 (permalink)  
 
Join Date: Jun 2009
Location: NNW of Antipodes
Age: 80
Posts: 1,330
Likes: 0
Received 0 Likes on 0 Posts
ACARS data origins

@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
mm43 is offline  
Old 17th Jun 2009, 06:14
  #1766 (permalink)  
 
Join Date: Mar 2005
Location: England
Posts: 730
Likes: 0
Received 0 Likes on 0 Posts
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.
Fargoo is offline  
Old 17th Jun 2009, 06:33
  #1767 (permalink)  
I don't own this space under my name. I should have leased it while I still could
 
Join Date: Dec 2002
Location: Lincolnshire
Age: 80
Posts: 16,777
Received 5 Likes on 5 Posts
Originally Posted by mrs nomer
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.
Read the thread.

New aircraft 4 yrs, 18000 hrs, IIRC.
Pontius Navigator is offline  
Old 17th Jun 2009, 06:40
  #1768 (permalink)  
 
Join Date: Apr 2004
Location: Tomsk, Russia
Posts: 679
Likes: 0
Received 1 Like on 1 Post
Originally Posted by TerraHertz
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 . 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 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
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.
selfin is offline  
Old 17th Jun 2009, 07:00
  #1769 (permalink)  
 
Join Date: Jun 2009
Location: Paris
Posts: 691
Likes: 0
Received 0 Likes on 0 Posts
Pitots

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.)
takata is offline  
Old 17th Jun 2009, 07:04
  #1770 (permalink)  
 
Join Date: Dec 2001
Location: what U.S. calls ´old Europe´
Posts: 941
Likes: 0
Received 0 Likes on 0 Posts
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 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.
Volume is offline  
Old 17th Jun 2009, 07:20
  #1771 (permalink)  
I don't own this space under my name. I should have leased it while I still could
 
Join Date: Dec 2002
Location: Lincolnshire
Age: 80
Posts: 16,777
Received 5 Likes on 5 Posts
Originally Posted by Volume
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 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?
Pontius Navigator is offline  
Old 17th Jun 2009, 07:54
  #1772 (permalink)  
 
Join Date: Jan 2008
Location: southwest
Age: 78
Posts: 287
Likes: 0
Received 0 Likes on 0 Posts
PJ2

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.
Dysag is offline  
Old 17th Jun 2009, 07:55
  #1773 (permalink)  
 
Join Date: Nov 2006
Location: SoCalif
Posts: 896
Likes: 0
Received 0 Likes on 0 Posts
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
Graybeard is offline  
Old 17th Jun 2009, 08:31
  #1774 (permalink)  
 
Join Date: Jun 2009
Location: Sydney Australia
Age: 68
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
ACARS origin

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.
TerraHertz is offline  
Old 17th Jun 2009, 08:37
  #1775 (permalink)  
 
Join Date: Aug 2007
Location: UK
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
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
d747 is offline  
Old 17th Jun 2009, 09:22
  #1776 (permalink)  
 
Join Date: Aug 2006
Location: firmly on dry land
Age: 80
Posts: 1,541
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by d747
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.
Wader2 is offline  
Old 17th Jun 2009, 09:45
  #1777 (permalink)  
 
Join Date: Jul 2008
Location: West Midlands UK
Posts: 44
Likes: 0
Received 0 Likes on 0 Posts
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 . . . .
minstermineman is offline  
Old 17th Jun 2009, 11:23
  #1778 (permalink)  
 
Join Date: Jan 2008
Location: Herts, UK
Posts: 748
Likes: 0
Received 0 Likes on 0 Posts
A little more optimism... 17th June BEA TV statement

French: No conclusions yet in Flight 447 probe

French: No conclusions yet in Flight 447 probe - News
HarryMann is offline  
Old 17th Jun 2009, 12:20
  #1779 (permalink)  
 
Join Date: Aug 2005
Location: London
Posts: 45
Likes: 0
Received 0 Likes on 0 Posts
JASC

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
John47 is offline  
Old 17th Jun 2009, 13:20
  #1780 (permalink)  
 
Join Date: Jun 2009
Location: France
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
BEA specialist not authorized to attend autopsies

In French, at Le Point : actualité internationale, économie, actualité Française (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 , 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.
gillesf is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.