AF447

[FLY400]

PJ2

If I (FLY400) am one of those new posters to which you refer, I will be very happy to continue the ADS-C discussion on a new thread, maybe in Tech Log. Or, alternatively I can butt out completely and just continue the private email disussions that I have been having with Lemurian and PK-KAR.

I was mererly answering a question in this thread. In this case, as an expert witness.

FYI, I was one of the original team at ISPACG that put together the protocols for FANS 1/A, as was the amazing guy that maintains the website at ATC DL News Home which he does gratis, in his spare time. Craig is one of the most dedicated, professional and practical Air Traffickers that I have ever had the privilege to meet.

Patience my friend.This is a very complex puzzle and is going to take a very long time to sort out. I admire your inputs in this forum and understand your frustration.

To sort it out is paramount for for the sake of those who lost their lives and our industry! Please, the searchers will find the wreckage and the CVR/FDR.

David

[Lightning6]

Originally Posted by Dysag

If AF447 took additional fuel it would at least give a clue that they were prepared to deviate around the weather.

If they didn't take more fuel, it tells us nothing. The extra fuel required to pass 50nm to one side and then rejoin the original track is almost negligable: just a fraction of the en-route contingency already on board.

IMO, if they didn't have enough fuel for a diversion around the CB (Which I doubt), they should have diverted back, probably posted on here before, but this thread seems to be going round in circles and getting nowhere!!

Having said that, it's been interesting reading this thread, if only for the technical information learnt.

[BOAC]

Originally Posted by JD-EE

That raises another can of worms.

- can I kill that one straight away please? Quite 'normal' to 'leave the ramp' over Max take-off mass - there is a 'max ramp mass' published for aircraft. They took off BELOW max take-off mass, therefore there is anything wrong there.

It appears that they fuelled to max. With ETOPS there are always options at all points along the route for diversion etc if necessary. 940kg is as much as they could get on and was apparently ABOVE the 'extra' required for the ETOPS planning. Cannot see a problem there. A well-planned 'detour' around weather does not burn that much extra.

[PJ2]

To those who offered their thoughts on my last post above, thank you.

I didn't communicate my thoughts very well but my contribution was motivated by a slight frustration with the minutae - a half-mile here or there with regard to the last position, the finely-honed discussion on intrepreting the report and so on - clearly such discussion has meaning for others but didn't seem to be advancing what we need to understand most which is, what caused the accident. I think lomapaseo has made a good observation and suggestion. As for me, I'll adopt a more patient stance. Again, thanks for the feedback.

[CONF iture]

The coordinates for the last position received are 3 NM abeam the Airway UN873.

There is absolutely no justification for the Interim Report not to explicitly mention that information.
To limit the analysis to the following comment is not satisfactory :

Originally Posted by english copy p. 68
up to the last automatic position point, received at 2 h 10 min 35 s, the flight had followed the route indicated in the flight plan

[Will Fraser]

CONF iture

I think there is a fair amount to criticize in the Prelim. I for one do not understand the apparent anger it provokes in some. No document is perfect, and if notice of some discrepancies is ok as regards AB or NavAids, I question the 'protectionist' stance of some for the BEA. We are all human here.

[Captain Bob]

Offset

BEA never mentioned AF447 was 3 NM off track ... WHY ?

It doesn't matter. Everyone does it. Parallel Track. It has nothing to do with
what happened.

[John47]

USA Today has a round up of AF447 so far - nothing new but interesting comment from John Fish

Even though ships have prowled the Atlantic in vain for several weeks in search of the jet's two crash-proof recorders, chances are still good that the recorders and the wreckage will be found, according to investigators and deep water salvage experts.
John Fish, a sonar expert who has helped recover underwater aircraft wreckage, said he's optimistic that a thorough search of the ocean bottom will help uncover the jet's remains.
"They are going to find it," Fish said. "It's just going to take longer because it is in deeper water."
The search is similar to what occurred after a South African Airways jet crashed in the Indian Ocean on Nov. 28, 1987, Fish said. Initial attempts to listen for the pingers on the recorders, which were nearly 15,000 feet deep, were futile.
But a U.S. team using sonar located the wreckage two months later. More than a year after the accident, one of the two recorders was found. The cockpit recording confirmed that the jet had been brought down by a fire.

Air France crash still a mystery - USATODAY.com

[Dysag]

"They are going to find it, fish said"

[HazelNuts39]

Offset

RE: Captain Bob (#3536)

Quote:
It doesn't matter. Everyone does it. Parallel Track. It has nothing to do with
what happened.
/Unquote

I thought so too, but after reading about SLOP (Strategic Lateral Offset Procedure - Wikipedia, the free encyclopedia) I felt that maybe 3 NM left of track is possibly significant. With as little evidence as we have, it would seem justified to examine even this detail.

Quote from BEA Interim Rept:
Note: A position report message (AOC type) was received at 2 h 10 min 34 s, between two maintenance
messages. This can be explained by the fact that AOC messages take priority over maintenance messages
/Unquote

Considering that the first WRN message transmitted by ACARS was received at 02:10:10Z and the last position report at 02:10:34Z - I wanted to have a feel for how much time it would take to get 3 NM off track, if one assumes that the airplane is initially on track at 468 kt TAS. For example, in a relatively shallow turn (10 degrees of bank) it would take approx. 80 seconds, or 10 NM along track, and a change of heading of 33 degrees. Similar data also for steeper turns are shown in the following table:

Track deviation [NM] . 3
TAS .[kt] ............ 468
Bankangle .[deg] ...... 10 ..... 15 .... 20 ... 25 .... 30

Loadfactor .......... = 1,015 . 1,035 . 1,064 . 1,103 . 1,155
TurnRadius [NM] ......= 18,1 . 11,9 ... 8,8 ... 6,8 ... 5,5
TurnRate [deg/sec] ...= 0,412 . 0,625 . 0,850 . 1,088 . 1,348
Heading Chg [deg] ... = 33,5 .. 41,6 .. 48,9 .. 55,8 .. 62,8
Time [sec] .......... = 81,3 .. 66,5 .. 57,5 .. 51,3 .. 46,6
Dist along track [NM] = 10,0 .. 7,9 ... 6,6 ... 5,7 ... 4,9

P.S. As you might guess, I'm an engineer, not a pilot, and a newcomer to this forum. If it's irrelevant, don't get angry with me, just tell me and I'll be happy to hit the EDIT button to delete it.

regards,
HN39

[rgbrock1]

Will Fraser wrote:
Quote:
The two pilots noted turbulence in real time, not as a tx. Not that they 'reported' it, they made note of it to eachother, or FP communicated it to PNF.

Thanks for clearing that up for me. I missed that bit.nh


What? I don't understand. If the pilots noted turbulence in real time and not as a transmission, and they did not "report" it, yet they made note of it to each other.... how do we know this?

[DJ77]

from Captain Bob about offset:
It doesn't matter. Everyone does it. Parallel Track. It has nothing to do with what happened.

You seem to be unfamiliar with oceanic airspace navigation rules. Prior to the introduction of Strategic Lateral Offset Procedures (SLOP) the only authorised navigation was strictly on the cleared track. Without describing history and justification of SLOP which would be a bit out of topic, navigation is now permitted either on track, or 1 nm right of track, or 2 nm right of track. Application of SLOP does not require ATC clearance. Other rules apply for emergency situations and weather avoidance to cope with the fact that HF communications generally do not allow immediate delivery of ATC clearances.

Has the 3 nm left cross track error (XTK) reported by ACARS at 0210 something to do with what happened? Well, I would say that it depends on what happened exactly, what caused the crash.

Allowing for FM / GPS difference, rounding, ACARS transmission delays etc ... this XTK shows with certainty that AF 447 was steering off track when the AP disconnected and this was not in application of SLOP. Since I do not see why they would be doing so unintentionally or for no reason, I believe they were performing weather deviations. Whether these deviations were pertinent and appropriate I don't know at all.

Among possible hypothesis, perhaps the crew shifted their focus from weather avoidance to unreliable airspeed procedure/alarms and then inadvertently hit a convective cell and lost control. By the way, what would you qualify as the main cause of the crash in this case?

[Will Fraser]

My post has been edited to include the word 'hypotheticals'. There are more than one possible ways to interpret the crews 'decision' to allow autopilot to continue prior to auto disconnect. The release of control by auto was either 'anticipated' or a 'surprise', or something in between, and bears very heavily on what happened next, (or had happened 'already'). eg. The cause of disconnect by exceeded control limits of a/p? The cause of disconnect Unreliable a/s? If a/c was deviating for weather, was it because of turbulence at the moment, was it Radar data? Was it both escape and avoid? One strong possibility is that there was not turbulence that was a factor, and the crew was merely deviating having monitored LH, and/or Radar. That is supported by the continued use of a/p? This may also serve to focus more on an Unreliable a/s problem causing release of control by a/p?

[rgbrock1]

Surplus one wrote:

Germans? Well we all know there is just nothing arrogant about a German, now is there? Germans are more perfect than anyone. Lufthansa would never lose an airplane due to its "safety culture". That's impossible!


Surplus One: i take exception with your implied remark. I do not think Germans, as a people, are any more or less 'arrogant' than any other peoples. To subscribe to such a statement based on a superfluous media report shows some serious narrow-mindedness on your part.

[Hyperveloce]

The last fault report received (02:14:20Z)

02:14:20 - .1/FLR/FR0906010213 22833406AFS 1,,,,,,,FMGEC1(1CA1),INTERMITTENT
FMGEC1 (1CA1) (2 h 13)
ATA : 228334
Source : AFS
Identifiants : -
Classe 1, INTERMITTENT
Hi there.
This last FLR has not been fully explained by the BEA (it is said that this would be a transient/intermittent problem with the FMGEC, raised by the AFS, for an anomaly of less than 2.5 s).
This occurred 3 minutes and 10 sec. after the A/THR off, presumably linked to a Pitot problem, and this Pitot freezing problems did not last more than 2 or 3 min in the other known occurrences of Pitot problems: could this unexplained FLR be linked to airspeeds fluctuating back to their nominal value ?
Would it be possible to look into the Airbus TSM to get all the possible problems this FLR might point to ? (to see whether some of these are linked in any manner to airspeeds, to airspeeds out of the flight enveloppe, etc...)
Jeff

[CONF iture]

Originally Posted by Captain Bob

It doesn't matter. Everyone does it. Parallel Track. It has nothing to do with what happened

To state "it doesn't matter" belongs to you.
To present the simple data in a 100+ pages Preliminary Report is a duty for the official investigating team.

Now, would you present the document that allows you to adopt a Parallel Track 3 NM on the left ?

[PJ2]

GB;

The Collins radar on the AF330 fleet is highly monitored, and since it's an essential system, any detected failure would be transmitted via ACARS so that maintenance would be prepared to fix it.

Possible undetected failures would include:
*Heavy coating of ice on the radome - highly unlikely.
*Antenna plate coming detached from its pedestal. It is attached by clamps held by two small bolts that are safety-wired. That one is pretty rare, too.
All other functions, including antenna drive position, are monitored, and hence any failure would be reported.

Water ingestion into the honeycomb structure of the radome may cause false targets, but will not get large enough to matter at altitude, once frozen.

It's been asked but I don't think answered in the thread - the radar would fail with the loss of all IRS data, (which had occurred by 02:13Z). There are two transceivers. ADIRS 1 supplies tcvr 1 with ADIRS 3 as backup, and ADIRS 2 supplies tcvr 2, with ADIRS 3 as backup.

The failure messages would be:

WXR ATT (amber) : Attitude control failure.

WXR STAB (amber) : Antenna stabilization failure.

According to the AOM, these particular messages are displayed on the ND, (nav data display). According to the A340 AMM, (I am assuming a similar installation on the A330):

Re "heavily monitored", yes it is. The BITE montors the radar system itself as well as the periherals, (EFIS CTL PNL, ADIRUs & CMC - Central Maintenance Computer). All failure messages and BITE results are immediately transmitted to the CMC. The ATA failure codes are:

RADAR Transceiver....................................34-41-33
RADAR Antenna.........................................34-41-11
RADAR Control Unit....................................34-41-12
RADAR No Data From ADIRU......................34-12-34
RADAR No Data from EFIS 1 Panel..............22-81-12
RADAR No Data from EFIS 2 Panel..............22-81-12
RADAR No Data from CFDIU........................31-32-34

I think we can assume that the radar could function up until the loss of the IRU data.

PJ2

[fantom]

Now, would you present the document that allows you to adopt a Parallel Track 3 NM on the left ?

CONFijam, we have all used offset to avoid a nasty looking mass of CBs. If the AF crew were faced with nastiness to the right and took the view that an offset to the left was the better option, would you have asked them to produce the doc allowing it? Who are they going to hazard on an oceanic track by going 3nm left instead of two right?

[Will Fraser]

I think CONF iture's point is that any deviation from 'en route de vol' should have been mentioned in the report. The motivation is not known, but isn't it established deviation is PIC's discretion? Also, 3nm in 119 appears to be a straight line and gentle course, who is to say the 3nm does not represent a 60degree left turn, made in urgent fashion?

Also, my understanding is that 'present the document' means would Capt Bob produce a report of accident without the notation of course discrepancy?

[BOAC]

Originally Posted by PJ2

I think we can assume that the radar could function up until the loss of the IRU data.

- I must have missed this in 3500 posts - has the loss of IR information been confirmed, then?