bearfoil, quote:
"No human endeavour can trump Physics, let alone the parochial attitude of those involved. Why again is the DFDR inside the fuselage and not the Vertical Stabiliser ?? Given the "Good Luck" Airbus demonstrates re: the independent ability of the VS to survive horrendous crashes??"

Another triumph of ambiguity. Starting from the second sentence I've quoted, which phrases are pure irony, and which (if any) are straight? Are we still to infer that the fin separated in flight?

As for the first sentence, and the rest of the piece, I'll reserve comment.

more hindsight
 

I could add the following to my previous post on what influenced the search strategy.

The retro drift analysis by the Brazilian Navy and USCG, pinpointing the impact so close to LKP and to the actual impact site, didn't get the attention that it deserved. Because there were other analyses, mainly by Meteo France (based on other models) that gave hugely divergent results.

And also the item that was found on 7 June on the surface of the impact spot was not seen other than an anomaly, while (as mm43 said before) it was probably a floatable piece recently escaped from the wreckage on the ocean-floor.

Moreover, because ULBs normally don't fail the search was very much focussed on that: until 10 July (the 30 days certified + 10 days of expected but not certified days of functioning) nobody was expecting not to find any pinger signals.

It was not after all the vast areas covered by sidescan sonar had not rendered any result either, that based they came closer to LKP again. On the one hand this was determined by what was left "un-sidescanned" and on the other hand on the recent the Russian study that showed how close to the initial upset point A/C that experienced LOC in cruise ended up at 0 ft.

But in one thing BEA has always been adamant: "AF447 has never been south of LKP" (except in cruise of course).

Looking fwd to the read-outs of the recorders......

I think what one infers as ambiguity may perhaps be sarcasm. An open mind is a fertile field.

RR

Is the picture showing the debris field an indication of the plane´s heading?

No, of course not. It shows the direction of the debris, as it sank.

An a/c that is rotating, laterally, out of control, cannot have a heading.

The "system" as it falls, can have a direction, though "random".

The direction of the nose as the a/c impacted is random, undirected, and most definitely not commanded. For the umpteenth time, "En Ligne de Vol" is a fantasy.

True, but they were working from a set of manually-calculated DR coordinates that were accepted to be a considerable way off, as opposed to a computer-generated log which showed damn near the precise path the target was taking up until it disappeared.

Kudos for your post
 

Bearfoil,

A serious one! Why? ASAP the investigation ends, better for the most important entity of aviation industry: THE PAX and CREW of ALL 330


We hope we will be able to verify

"People are being entertained" Let´s hope for readable boxes and even QAR.


N/C

I read like that

If your objective is to work respecting THE PAX and CREW of ALL 330 and similar planes

I remember Michel Asseline of Habsheim 320


AirDisaster.Com: Investigations: Air France 296

To be continued in following post(s)

Shape of debris in ocean floor
 

Bearfoil,

What i thought:

Plane disintegrates (falling stalled at unusual attitude) when hitting sea surface with SOME horizontal speed.

My question relates to:

The debris shape in ocean floor is representative of the spreading of debris in sea surface when it disintegrated?

Or derives from sea currents when dived?

Observe i used DIRECTION instead HEADING.

In the text i edited also.

I agree with you that En Ligne de Vol" is a fantasy

Part of the "Entertainment" you mention.

bearfoil;
Sir,
The ship has a "bow" and a "stern", and when proceeding in the same direction as its "bow", the vessel is making "headway". The counter applies if proceeding in the direction of its "stern". This being the accepted case, the vessel at all times has a heading in respect of the compass rose which lies in a horizontal plane.

So, irrespective of the vessel turning to port or starboard, or spinning, the only time there is no heading with reference to our compass is when its bow and stern are respectively in line with the zenith.

Now, commanded or not, the "en ligne de vol" provided the vessel with a heading as would be expected of any vessel "en passage". :ok:

RR NDB wrote:
In my sense, it's not possible to see an heading value of the plane when impacting water.

IMO, I hope everybody here is knowing that the sea floor wreckage parts from EST to West repartition is only the result of submarine flow AND density + shape factor of those parts.

regards

RR NDB

One need not be an expert. At impact, most of the a/c was in structural chaos, and there was no horizontal component after some milliseconds. The debris ended up tight and probably in some sort of teardrop shape, from above. After that which would sink, sank, what formed was a conga line of debris, subject to current alone, no wind, trajectory, nor "Heading". The debris field may have been 600 meters across, maybe not, but what is seen on the bottom is the "target" established upon sinking, subject to rate differences. The trajectory below the surface was down, probably to a precision of 99.9 per cent. Travelling two and one half miles vertically and 600 meters horizontally, if the debris field was as tight as 600 meters, that there was no dispersion is indicative of almost no current, for if there was, there would be a dispersion, heavy to light, etc. The debris field found on the seabed suggests not dispersion but coalescence. Here the "intact at impact" is reinforced, since to fall on to such a small target from 2.5 miles away means that most of the debris at least started its journey as a joined mass.

It may be a language thing, but I doubt it. An object in free fall has a Trajectory, not a heading.

Has one found the second, Starboard engine??

En ligne
 

mm43,

En ligne de vol?

Vol=Flight

The a/c hit sea surface flying?

Or stalled at unusual attitude (like a falling "winged brick")?

This is why i put DIRECTION instead HEADING in post #599

You must be ignorant of extensive discussions of this phrase in earlier editions of this thread. The phrase is used in the very last "Finding" of the first interim report, that is an unfortunate collection of ambiguous, inexact descriptions of the impact conditions. (The english translation is even worse). The BEA has evidently recognized their error, and has carefully rephrased it in impeccable engineering language in the second interim report:
I frankly fail to see the merit of continuing to refer to the poorly worded first edition, since it has been corrected.

It is important that "heading" and "en passage", not be included, they are misleading, notwithstanding the "modification" of the BEA's language. It was not a correction, merely a quiet abandonment of a gross error.

Unknown horizontal trajectory
 

Ok!

Debris field shape at sea floor not related to a/c fall trajectory!

Good question on engine #2. Where it is?

I want to see also where is right wing, the right main L/G, etc.

It cannot be far, for the aircraft hit the water's surface intact.:hmm:

Words or gross error
 

HazelNuts39,

I commented bearfoil post and his specific line on "ligne de vol"

I will analyze this issue in the BEA reports trying to see if was "words" (terminology) or "conceptual errors" or occurred from (an)other reason(s).

Will do it ASAP.

Thanks for clarifying an important issue.

Bearfoil;
.. and thank you for
:D

Where are you getting this from ?? Who kept away from LKP and when ?

From what I've read, the first two search phases were all covering zones "centered on LKP". Phase 1 mostly looked for pinger signals, plus (as I read it) some additional Phase 2 ROV searches to cover areas where they'd run out of time on Phase 1. In addition, they did complete bathymetry of the area to inform future searches - 40NM circle, where ? - centered on LKP, again.

Only in Phase 3 did they do something different - only after having failed to find anything with a general search centered on LKP, they searched an area calculated from drift analysis of the wreckage. That turned out to be wrong - but with so many variables and uncertainties and the delay in finding the floating wreckage, that's not really suprising. But surely it was worth trying?

Phase 4 went back to square 1 effectively, looking for wreckage rather than pingers, and starting from... - LKP, again.


So in what way were they ignoring or avoiding LKP or assuming the plane flew on for longer ? They centered everything on LKP!

Don't they (VS) have a habit of falling off in flight ? :)

More seriously, it's because some time ago someone decided that tail was most survivable place (probably is in most accidents - not this one though), and they need to be somewhere accessible for maintenance I believe. Someone also decided there should only be one recorder (of each type), very well protected. Probably right in the days of bulky and expensive foil and tape, maybe not now, when gigabytes of solid state memory is a few $ and smaller than a fingernail.

We could probably all do a better job of designing a recorder system now, with hindsight and infinite retrofit budget, but lets not forget that the current CVR/FDR system actually has a very good recovery rate when you consider the number of possible ways to crash a plane.

[ ULB failure in this case definitely needs looking at - doesn't look to be any difficult terrain reason for failure as was suggested before ]

VS acting as antenna and perhaps the whole empennage
 

JD-EE,

Any metal inside the Tail Fin will act as an antenna (considering you are coupling it in a "shunt feed" approach)

Even the VOR (DUAL) antenna coax cable (outer shield) located near tail fin tip would radiate and (receive signals).

I don´t know the HF behavior of the material EADS used in VS. And i am neglecting it´s influence.

And for sure there are other metallic parts in the A/B VS newer planes than just VOR (DUAL) cable.

Perhaps ALSO the HS is "in the antenna".

I suspect the antenna is actually the whole Empennage.

Therefore presenting some "horizontal polarization"

Later we will talk about this specific issue.

Rgds,

Phases
 

infrequentflyer789,

Look:

http://avherald.com/img/af_a332_f-gz..._090601_24.jpg

http://avherald.com/img/af_a332_f-gz..._090601_21.jpg

http://avherald.com/img/af_a332_f-gz..._090601_22.jpg

When hit sea surface, INTACT
 

NeoFit,

If you have an in flight breakup may be would be able to "recover" it´s trajectory.

#572. BEA is listening.
 

They heard me. They have set the "Press Release & Information Points for all daily releases back to French being the first URL link.

Sea Search Operations, phase 5

National pride is restored once again!

unmanned transport,
"Just an idea.
A roll of dayglo orange tape, say 50 feet long should be attached to the CVR and FDR so that it will unfurl and make them easier to find."

I think it's an excellent idea, and you are not the first one on the various AF447 threads to suggest it. And neither was I...

bearfoil,
"The direction of the nose as the a/c impacted is random, undirected, and most definitely not commanded."

Your description of the flight of an aeroplane that has lost all directional stability is a neat one, and consistent with your hypothesis of the entire fin being lost in flight; unlike the residual stumps of the JAL B747SP, or the B52 in the video link posted by RR NDB above.
No ambiguity there. :D

To continue the discussion hypothetically, let me suggest the possibility that – having read successfully the FDR, under the noses of foreign experts – the BEA may announce in due course that any recorded sideslip, up to the moment of impact, is not sufficient to be consistent with the absence of the fin, and that the rudder position parameter is available and valid throughout?
In that event, however surprising it might seem, would you accept the validity of the evidence?

Here we go again... *sigh*.

I'm sure he's a decent man, but on that day his lack of attention to detail destroyed a million-dollar aircraft and killed three* people. There's nothing else to be said.

This thread is about AF447, not AA587 or AF296. It's about details that we currently don't know, but will hopefully be salvaged from the FDR and CVR. It is not about bashing the French investigators (who have deservedly overcome the bad press that followed them through the 80s and 90s), whispering surreptitiously about composite empennage lugs (that nevertheless held on considerably past their ultimate design load) or a conspiracy by Airbus Industrie to de-skill the profession of airline pilot (an argument I'd like to see the doubters on here have with A320 Captain Chesley Sullenberger).

[* - h/t ARZ]

I wonder if tapes might, for example, impede the recorders escaping the fuselage (by snagging on things) where they might otherwise escape & hence make them more susceptible to fire damage? It's such an obvious idea, I kind of wonder if they haven't already considered and rejected it for some other reason?

Recorder in VS would be bad for a simple reason:
Unless you can guarantee that it will stay attached under all conditions (proveably unlikely) you risk a worst case scenario of the recorder hanging on to the -floating- VS for a day or two and dropping into the deep at a location totally unrelated to the rest of the debris field.

In the AF477 case that would likely have resulted in never finding the recorders.

Chris

I am unsure the authority of the VS v/v Directional Stability at fifty knots forward, and 160 down. I am not persuaded that the VS would have made a difference at these conditions, whether on or off. You picture me as fixated, and that's fine, but I have not rejected any possibility. You, like most, see an adamant argument, and think it obsessive. At the very least, you take offense and immediately know all other possibilities are bunk, to this person. You are of course wrong. No one knows what happened. Not yet, and until the findings are sussed and confirmed, it is at least as illogical to reject a theory as to embrace its corollary. Objectivity can wear a tuxedo, or a shopcoat. Until BEA abandoned its jargon that described their very own opinion as bunk, and to this day, people picture this a/c as somehow in control and dogged by bad luck. That is the puffery of a partisan, or his "Friends".

I am a follower of Murphy, but did he not also understand sarcasm??

"ligne de vol" = "level attitude" (and nothing more)
 

As HazelNuts rightly points out, there was extensive discussion of this phrase in Part 1 of this thread (back in early July 2010).

For anyone who has not seen that discussion I suggest a quick look at these posts:

#3300 (8 July page 165) NOTanAM

#3301 (8 July page 166) Lemurian

#2808 (3 July page 141) Lemurian

(And thanks to all the regular, expert, posters for such an interesting thread).

Murphy´s law never fail so let´s go to REDUNDANCY
 

MurphyWasRight

Considering this fact and LOW COST CHIPS i "propose":

1) Multi CVR/FDR (combi) at wing tips, VS, before and after "aft pressure bulkhead" and in other strategic locations (perhaps, at LDG´s)
2) Use batteries to avoid becoming useless after a complete electrical failure in the aircraft.
3) Improve their capability to be located (pingers, special ELT, ressonant transducer, etc.)

Real time data streaming (telemetry) IMO does not seem practical for many reasons.


PS

Instead of just one ribbon, better to use many shorter ones. The long one can be entangled and later buried underneath a big part rendering a pinger or special ELT, "mute".

auraflyer, quote:
"I wonder if tapes might, for example, impede the recorders escaping the fuselage (by snagging on things) where they might otherwise escape & hence make them more susceptible to fire damage? It's such an obvious idea, I kind of wonder if they haven't already considered and rejected it for some other reason?"

I also wondered. It would have to be capable of breaking off in extremis, but wrapped so neatly that it was unlikely to catch on anything. So how would it then deploy?
If detached, it could end up anywhere and would be quite a red-herring (sorree), but worse problems than that have dogged this search...

Of course in this case, orange tapes might have saved a few days after the wreckage was located, but wouldn't have helped find it in the first place.

"ligne de vol" = "level attitude" (and nothing more)
 

MJC2,

Coul you indicate the links (url) of:

#3300 (8 July page 165) NOTanAM

#3301 (8 July page 166) Lemurian

#2808 (3 July page 141) Lemurian

I also think future FDR/CVR installations should be distributed. Engines always seem to be found easily because of their mass, I would think burying one pair of the units in each engine where it is secure, and armored, would be a good idea.

Another pair should be in a floatable buoy.

I suspect certificating entities will have to mandate it before it is done...

The links provided by MJC2 are:-

AF447 #2808 p141
AF447 #3300 p165
AF447 #3301 p166

With regard to Lemurian's post #3301, I believe he has laid out the true circumstances of the aircraft's arrival at terra oceania. In the sense that the attitude was nearly level and the vertical rate of descent was high, the matter of direction of travel (or speed for that matter) was virtually irrelevant. Though, as HazelNuts39 has reiterated, the BEA did modify its stance on the "en ligne de vol" in its preliminary Report No.2.

Distributed recorders (redundant)
 

Khashoggi,

Indeed, engines are more "locateable" than a tiny "free" CSMU.

Just one recorder can be enough for Data and AUDIO.

The info is the same: BITS.

The AUDIO recording is the same thing of DATA recording.

The era of Audio (analog) and DATA separated is gone.

So the cost also. (Dropped)

There is room for improvement. This case will help for changes.

2 years + waiting for a result (analysis and recomendations) of this magnitude is IMHO an ABSURD

Unfortunately the Regulatory, etc. entities are not proactive. They trail the crashes. Managed by bureaucrats.

And the "technical people" has not the tools for the "decision making"

Links
 

mm43,

Will read ASAP.

When we comment unfortunately in most of cases we have no time to read everything was posted. When searching for the links i also found multiple threads on this issue.

Recorder Locations
 

1. The recorders are placed where they are least likely to be damaged in the typical crash. Of all the crashes in the jet age, only a handful have been into deep water.

2. The recorders may be used only once or twice in the lifetime of the airframe, if at all. The rest of the time they are dead weight. They may be used for FOQA, etc., but that is not primary purpose.

3. The recorders are certified with the airframe. Subsequent moving to another location would cost heaps of money, with little probability of return.

4. The recorders should be in a benign environment. That precludes mounting with the engine. The A330 FDR outside the pressure vessel is hardly benign, either.

5. The power to the recorders must be as secure as possible.

Recorder Locations (distributed memories)
 

Graybeard,

1) One of the least likely places to be damaged in most crashes is in the tip of VS. You can put one of tiny recorder there (actually the memory unit). I am not speaking of the currently available recorders. A new generation. Not a big R&D.

2) Can be light and cost effective. (only the memories to be redundant)

3) No problem

4) I would not say "precludes". Better to say, must take into account engines environment. I don´t see this as a big problem.

5) Redundant power (DC coming fro a/c and internal battery). An optimized design can be feed by Li ion easily for adequate time. No problem.

Ok, there are EMI/EMC considerations, costs, etc., etc. My point is, the current solutions should be improved.

No power, no data
 

And what would the recorders record after a complete electrical failure?