Tokyo Geoff

Perhaps Two hundred and one. Everything about this accident is speculation thus far.
There are missing pieces from any and all "conclusions". Not even the first report made conclusions, only informed speculation. So it remains.

Compared to established routine, some informed speculation has been offered. If the Fuselage impacted as BEA have said, the cockpit would have hit almost exclusively in the vertical, and the cockpit/nose area is reinforced beyond that of the "Tube". So right off a suggestion of pilots being trapped in situ. If the Captain was resuming his Left Seat, or walking forward from rest, he may have tumbled out the front shattered section of Fuse. There have been no reports of identifying injuries for those unseated. The only injuries referenced have been those concluded by BEA to have been of seated passengers.

Seats occupied have been noted on graphic, so one can unwind name/seat by manifest.

There is a strong possibility we have all the evidence we shall ever have. So, as you say, all will remain speculation. Let's simply hope the speculation will remain objective.

cheers,
bear

JD-EE

When viewed dispassionately, all hidden data hurts the hider, that is the impetus of the hiding?

Once flying my Manta Wing, I was overcome by an updraft that lifted the 'nose', I ended up on my back. Overrotated. I was an observer, not a pilot at that point.

The Autoflight has limits designed into it. As these limits pass the designed value, the Autoflight trips out. This introduces Alternate Law. Manual Flight. Dark as Coal, no Horizon, No Airspeed, two dozen warnings and alerts, Turbulence of "Fortes".

Sky King would be perplexed.

For cpp6f and vortex:

Not sure I'm the right guy to say this, but I got here first so here goes.

The airplane was flying in 'coffin corner'. This is a strange part of the flight envelope where stall speed and the maximum mach number converge. The stall speed is a constant indicated airspeed, based on 'q' or 'half rho vee squared'. And this is the problem, rho, the air density, decreases with altitude so the true ground speed for stall progressively increases. At the same time the speed of sound in air decreases with lower density and so with higher altitude.

At the flight level they were flying, I think it was fl370 or 37,000ft, the margin between airplane stall speed and structure maximum mach number was only 25 knots. Go slower and you stall. Go faster and you disintegrate. Don't know your airspeed and you sure as heck will do one or the other.

I hope this is a valid explanation, others greater than I will come after and will surely correct me.

Correct me if I'm wrong, but isn't indicated airspeed directly determined by the AoA which is directly controlled by the trim setting of the horizontal stabilizer and completely independent of engine power? So if I'm the pilot and I lose airspeed data in such conditions, I would assume I was already at a safe airspeed and AoA and not touch the trim, and then cut engine power to descend to a safer altitude. Of course, severe turbulence would cause temporary deviations from the equilibrium airspeed and AoA, but would a functional autopilot be able to correct these deviations faster than aircraft would by itself, thus reducing the possibility of a catastrophic deviation?

Now this is coming from a hang glider pilot with absolutely no experience in powered aircraft much less a 100 ton state-of-the-art transport so I may have no idea what I'm talking about.

By its nature, speculation is subjective.

I am intriqued by this talk of pilot (in)action in the face of contradictory evidence to the pilots

I always understood that Airbus was fly by wire and that the computer CANNOT be disabled under any circumstances.

momie sait mieux - as they say in Toulouse

Common Mode Failures
 

This is quite a bit oversimplified, but with Airbus, until you degrade fully to direct law, the computer is still trying to fly the aircraft as it sees fit, up to and including overriding the aircrew's input. All that "Autopilot" really means is that the aircraft is holding heading and altitude in accordance with its instructions, but the computer is still flying the aircraft.

Once the computer accepts bad data as gospel, it can start doing stupid things with the aircraft. All it needs is a trigger for all heck to break loose.

The computer gets its data primarily by accepting the middle (median) value of the 3 input channels for key flight information.. When some situation occurs that affects 2 or 3 of these data inputs channels in some common (but bogus) manner is when Airbus gets confused.

ACARS information from the flight indicates that all the Airspeed information channels were considered bogus at some point.

Sheer speculation below but possible initiators for loss of control are:

1. The Aircrew being confused by erroneous airspeed indications and stalling the aircraft in Alt (2) law.
2. The aircraft being confused in Normal Law, and applying the wrong dynamic laws for the aircraft and thus dynamically diverging from controlled flight.(Think servo system that is stable but too much gain.)
3. The aircraft being confused in Normal Law, and applying Mmo/Vmo protections inappropriately, then degrading to Alternate law and stalling.
4. Something even stranger that I haven't considered:}.

Actually, the airplane was flying at FL350, its 'coffin corner' was at FL460, and the margin between max. speed (Mmo=0.86; 295 kCAS) and low speed buffet (M=0.58; 192 kCAS) was 162 kTAS.

regards,
HN39

HN39,

Thanks for injecting some sanity back into the discussion.

We know the aircraft lost the ability to maintain stable speed and altitude, but how that came about and the apparent inability of either FBW protections or crew inputs to rectify the situation is why this thread exists. Hopefully by mid 2011 we will have factual answers to this conundrum and a resolution to an intriguing puzzle.

mm43

I believe that one can force the system to a lower law by pulling CB's / intentionally disabling systems.

The Perpignan A320 accident is a prime example, especially the out of trim condition following an unexpected law change.

mm43

Human vs. Machine
 

I have tried to keep up with this thread, but don't recollect having seen this discussion, so here goes.

Re the comments about PRIM, SEC related messages in BEA reports. The reports state it has not been established if the messages in question were the result of pilot action.

IMHO, if this information is available to the system, it should be differentiated on their ACARS signature. I'd think this is a pretty important piece of "maintenance" information.

HN39, as you have explained they were nowhere near coffins corner. Speculation on this thread is the only thing we have been reading other than some acars data transmitted during the incident. Does anybody else think by holding attitude angle, maintaining GPS GS and cruise power was the only option they had with total pitot/static freeze up? I hope they find the black boxes so they can find out what really happened. If
that was their only option even though GPS GS changes with prevailing winds it is better than nothing.

Hi p51

There is no shortage of speculation. But there are also a few fairly hard facts. The best chance of finding AF447 is to find an explanation that unifies these few facts.

1. We have bodies drifting North when they were found - in fact just a little west of north (357). Not ENE or NE as the current charts showed. This suggests that the point of impact is somewhere to the SE of where we have looked so far. How far SE is speculation, but I am fairly convinced that SE is the direction to look next. I believe this information provides the single best indicator of where AF447 may have ended up.

2. Takata extrapolated the observed drift of the bodies, and came up with an impact position of 1.915 N, 30.390 W. His theory to explain this was that the aircraft turned right to the SE an attempted to divert to Fernando de Noronha. This extrapolation was based on the assumption that the current was exactly the same for the 5 days prior to bodies being recovered as it was for the period when they were being discovered. In the absence of any definitive information, this assumption is as reasonable as any other. However my guess (speculation) is that the impact is not that far to the SE. If the aircraft had a significant period of controlled flight after turning, then you would have expected a radio call of some sort, evidence of life-jackets, and cabin crew secured in their seats. None of this appeared to have happened, and so it is likely that the end was faster than Takata's theory.

3. There was at least one (possibly more) submarines searching for the pingers. The mission and the very survivability of these submarines depends on finding things that are trying not to be found. How could they search for weeks and not locate something trying to be found? Sure the pingers have limited range - more so if you are listening several miles above them. Yes I appreciate the challenges posed by extreme depths and that submarine sonar is probably not designed to find enemy submarines that deep (there being no point). And multiple thermoclines and mountain ranges will complicate the task greatly. But nothing definite identified. I could accept not localised due to the complexity of pinning the source down. But not even heard. No other civilian assets heard anything either. We they all listening in the wrong place?

4. No life-jackets. No radio call. Cabin crew seats that were not used. All this suggests things went very bad very quickly.

I have left the pollution spot out of this as I do not think we really know its origin - thank you to mm43 for clarifying that. If you chose to include the pollution spot as a reliable datum point however, then this would also support a crash SE of last known position. Not very far however due too the proximity of this when found on the 2nd.

Can anyone produce a credible explanation of the aircraft turning (either controlled or not) to the SE, flying for some distance south of 3 N, and no pilot able to get out a radio call, nor cabin crew get to their seats, nor life jackets utilised?

question
 

If a NAV IAS DISCREPANCY ECAM MSG has/had been triggered, would/should it figure on the ACARS list ?

YouTube - Lost - The Mystery Of Flight 447 - Part 5

The BBC documentary speculates that the failure to increase thrust after the loss of AIS led to the stall. Correct me if I'm wrong, but on a simple aircraft with no automation, reduced thrust should not change the AoA - thus a stall should not occur - the only thing that would happen is the aircraft would descend in a controlled manner. So what are they really trying to say? Are they just dumbing it down for a non-technical audience?

I don't have much expertise here, but I'd still like to understand what might have gone wrong. Are these the possible scenarios that could have caused the crash?

(a) Severe turbulence caused the plane to stall or overspeed - thus the crash was caused directly by flying the plane into a powerful storm and the malfunction of the pitot tubes did not play a significant part. Thus it is suicidal to fly into such a storm even if you have a perfectly functioning flight control system and improvements in radar or interpretation are needed to safely fly through the ITCZ.

(b) It is reasonably safe to fly through such a severe storm if one maintains a large enough airspeed cushion above stall speed and below mach buffet speed. But without accurate airspeed data, this cushion could not be maintained and the severe turbulence caused the plane to stall or overspeed.

(c) The autopilot is unstable (in severe turbulence) with loss of airspeed data and caused the plane to stall. Had the pilots been in direct control of the aircraft the entire time, this would not have happened. This is corroborated by the incident on Quantas flight 72. Thus the flight control system of the A330 has design flaws that need to be corrected.

Any other scenarios that could have led to the crash?

bearfoil, "When viewed dispassionately, all hidden data hurts the hider, that is the impetus of the hiding?"

That is what is known as a tautology. It ignores the affects on third parties when the secret information is released. Your view is one I associate with people "who just want to see the world burn." That's not a healthy viewpoint. It ignores how most people would be quite unhappy to see the world burn, especially as they take part in the "festivities" as nice Roman Candles of ambulatory fat deposits.

Your shame still stands out, bearfoil, for not considering the collateral damage of satisfying your ego trip from the information release.

Slats11, some nits

Rather than a straight line approximation look into a second or higher order curve that better fits. The maps Saturn has put up show weak currents to the NE that turn into slightly stronger currents to the N and then even stronger currents to the NW in that region at that time. I'd expect them to have gone down to the West of the over simplified straight line estimate.

Fernando de Noronha is to the SW and has roughly a mile of runway. So that part of your comment raises a huge, "But, WHY?"

Regarding life jackets, I've noted it's really hard to reach that silly object in its storage under the seat cushion while I am strapped in to keep from kissing the overhead due to turbulence.

Pinger range is very short compared to the depth of the ocean where the plane went down. As you mention multiple likely thermal discontinuities make it even less likely a mere submarine at even twice its Wikipedia estimated maximum survivable depth would get close enough to hear the pinger.

Missing radio is a little unlikely. If the current setup was for transmit on DAKAR's frequency when the microphone switch on the joystick was pressed that could explain a lot. While the world is turning to (oops) around you reaching to reset the console to transmit on some other pre-tuned radio would be unusual. So I'm merely uncomfortable with missing radio calls, well before the situation turned bad. Once it went to perdition setting up to transmit a mayday on 121.5 or the like seems somewhat like the little mouse raising its middle digit as the owl swoops in for dinner.

Pick away JD.

The Fernando de Noronha theory was Takata's explanation for his drift analysis. Takata assumed the current was constant from the time of impact. As such he plotted the crash site to 1.9 N - a log way south of the last known position. I guess he could only explain the plane being that far south as being due to controlled flight - and I presume he therefore suggested a diversion to Fernando de Noronha as a possible explanation for this.

I buy Takata's drift analysis (in part). However I doubt that the plane was as far south as 1.9 N. There is no logical reason for it to be that far south, and if they did reverse course there should be some corroborating evidence to support this. Therefore the current was not constant from the time of impact. It was fairly constant (speed and direction) from day 6 when the bodies were first discovered. But it was doing something else for the first 5 days - who knows what.

The real point is that the bodies were not drifting in accordance with the current charts when they were discovered. At 3.5 N on the 6th, these charts suggest the current was to the NE. The bodies were drifting slightly west of north.

Therefore, the best thing to do with these charts is to ignore them. And keep an open mind as to where the bodies were drifting over the first 6 days. Don't attempt retrospective drift analysis based on charts which could only be tested once (days 6-10) and were shown to be inaccurate.

I have long forgotten whatever I ever knew about 2nd order curves. However that does not matter here. We have no idea what the currents were really doing. I am sure some datum buoys were thrown out by the FAB. But if they were not thrown out in the right area then they are pretty meaningless also.

Life-jackets? I can accept that not everyone would get a jacket on. I find it strange that no one got one on - these are the bodies that would most likely be found, and I feel that if 50 recovered bodies did not have a jacket on then probably no one put one on.

No Mayday or other call?

Very importantly, cabin crew seats were not used. The cabin crew are all taught the importance of using their seats - rear facing with shoulder as well as lap belts.

Any one of these factors? Shrug shoulders. However putting these 3 things together, it is hard to escape the conclusion that things went from routine to totally out of control very quickly. So nope, I don't buy the controlled flight to the south theory. There is nothing at all to support it.

So what are we left with. At some point soon after last known point, the most likely sequence of events appears to be a pitot blockage leading to stall and loss of control and a spin. Probably recovery of spin at some point (if we accept the BEA analysis of the impact). Then a rapid descent with some forward motion. The plane could have been pointing in any direction at that time, and so possibly a few miles were covered during the descent. My guess is that this was to the south. Based on 2 factors:
i) we have not found it and we have looked in most other directions
ii) a few miles SE does incorporate the pollution spot (that is pretty thin however).

Any unsecured cabin crew would likely have been incapacitated by this stage and hence would not have got to their seats. Any restrained pax that were still conscious were probably beyond doing anything as organised as putting on a jacket. And the pilots are probably not going to transmit anything at that point either.

From the beginning of this thread I have felt that the event occurred very quickly, and a rapid deterioration of flight occurred. The suspected fact that paxs were without life vest donned and that cabin crew were not at assigned, or any station seems to validate this. Anybody not seated, or probably belted, at the time most likely never reached a seat and were at the mercy of where they were placed at the onset of the event.

A stall would have ultimately placed the airplane on any random heading, particularly with the drop of the right of left wing. Resulting spin and rate of descent could extend the path in any direction. However, drift estimates should not be discounted. Can one say it is really the only simi hard fact to hang your hat on.

ccp6f
While I appreciate your effort at outlining some base scenarios, you mixed in a bit of hyperbole with a premise and conclusion there.
Your bit in italics seems to me a false dichotomy. FBW is a design practice that is used (successfully) throughout much of aviation - see for example high performance Military Jets since the F-16 or so.

If the Flight Control System in this, and or other Airbus designs (by which I assume you mean all other than the flight control surfaces themselves) could use an improvement, revision, or correction, why do you bring up "scrapped altogether" as an OR statement? That's a non-option, not only due to its risk to Airbus and its business base. Continually tweaking and correcting this, that, or the other is how the aviation business has been operating for some decades. Small improvements here and there, sometimes triggered by tragic events such as AF 447 ...

FBW is an industry standard that works well enough, regardless of my own or others' discomfort with some of its drawbacks.

From the early pages in this thread, a non-trivial amount of discussion has addressed the point that points to pilots having to fly/act when the auto functions degrade or change mode, for one reason or another. That doesn't mean that FBW needs to be scrapped, but it does require any professional aviator to know his aircraft systems inside and out, and to be familiar with degraded modes for any aircraft system or sub system.

Any pilot is going to be challenged if, quite suddenly, airspeed indication becomes unreliable. It's a key piece of information that is the foundation of any flying decision or action a pilot undertakes.

Thanks for pointing that out Lonewolf. I think I confused terminology and probably shouldn't have said that part. I meant the post to be a question, but I think it came out as more of a statement of fact. My aviation experience is limited to flying hang gliders, a lot of reading, and riding in the cockpit of my brother in law's 737 (who flies for a 3rd world airline where regulations are more like suggestions than law) so I really don't have much expertise in any of this. This crash has just been haunting and puzzling me ever since it happened and the engineer in me really wants to understand what might have happened. What I was trying to ask is what this accident could mean for the Boeing vs. Airbus flight control philosophy if it turns out that the computer stalled the aircraft. Anyway, I'll edit my previous post to reflect better what I was trying to say.

slats11

Back in August 2009, I had a look for available wind data over the first 6 days of June, and put together a small montage showing the Quikscat satellite 10m data. Its reproduced again below.

http://i53.tinypic.com/dnyfxf.jpg

Like takata, I came up with some different scenarios as to where the aircraft could have gone and why. Some were based on researching available current and wind data, and they placed the aircraft to the west of LKP. Others used LOC stall and spin scenarios and placed the aircraft relatively close (20NM) to LKP and to the east, but the current setting to the NW was not verifiable, though it was the seasonal direction published in some authortive texts. However, I've since learned how fickle the surface currents are in this area, and any of the positions I developed could be correct.

The one 20NM to the ENE of LKP (3°05'N 30°18'W) has not been covered by side-scan searching.

mm43

Hi mm43

As far as bodies are concerned, you can largely ignore the wind. This will have minimal effect on a mostly submerged human body. The overwhelming majority of body drift will be due to currents rather than wind. The wind component will be far smaller than the uncertainty about the velocity of the current, and so it is probably easiest to simply discount the wind this as a factor when attempting body drift analysis.

If you wished to allow some wind component, the winds were easterly rather than westerly. This would also suggest that east is the direction to search. The currents were pretty much due north for 5 days after June 6. Who knows what they were doing prior to this, but they were likely northerly rather than southerly. Hence SE is the best option - which also allows for the pollution spot if you chose to incorporate this in any explanation.

The easterly winds explain why so much other debris (which will have been much more wind effected) was found west of the bodies.

If you had some homogeneous debris (eg 20 seat cushions), then you could attempt some composite analysis. Assume the bodies were 100% current effected and the debris was some composite of wind and current, and then look for solutions. Unfortunately the debris is all heterogeneous, and hence each has its own ratio of wind and current effect. Thus the debris is really just noise, and it is best to confine the analysis to bodies (the only things which will have behaved similarly).

The bodies are all very tightly grouped together. Remarkably so after 10 days in the open sea. We know the current was pretty constant after the first body was discovered. You could speculate that the current had not changed direction a great deal prior to this - on the basis that changes in currents will favor dispersion and scatter. It probably changed speed however (slower prior to discovery of the first body) - because there is no logical explanation for the plane to have got to Takata's original position. This however is all very qualitative rather than quantitative in nature.

Current and Drift ...
 

mm43

Ref: your previous messages #2479 and #2491

Since a few days, I can't understand what is the real North equatorial current! (sure, it is very changing twice a year).

I had been very surprised reading pages 30 and 32 of this report (released 2010,oct. 5).

If pages 28 or 30 are very well known , the nine drifting buoys tracked in page 32 clearly show that south-EST zone investigations might be very interesting (Unfortunatly, I don't know what day/mounth/year Coriolis data base is refering).

Regards

NeoFit

The eight Self Locating Data Marker Buoys were air-dropped between 0330 and 0430z on 04 June 2010. They were tracked for many days, and perhaps you and Slats11 will now have a better appreciation of why I was trying to explain that the currents within this region are as unpredictable as a chimp's handwriting.

http://i56.tinypic.com/fm5phj.jpg

The Orange and Yellow drifters dropped to the east of the LKP exhibit the greatest commonality in their tracks. They have effectively drawn what is known as the Equatorial Counter Current, while the others have fallen into "no mans land" and have made various rates of progress, in a generally clockwise direction.

Are these tracks in anyway representative of what happened in the first week of June 2009? No they are not, and I would offer that the pattern observed in the graphic above will never repeat again.

The point I have made before and shall reinforce again, is that the matching of what happens in practice with the events that cause it, is not simple. Much effort has been made to date to try and replicate these tracks using many adjusted variables. Until the methodology can be refined, and a better understanding of the small physical changes that propel the surface currents in this area, our ability to backtrack with any degree of confidence is quite limited.

Slats11

There was low profile debris found to the east of the general line in which the bodies were found. I am not going to argue the point over the leeway issue, except to say that they did make a small amount of leeway for reasons I explained earlier. The 10m wind (with lower level surface friction taken into account) was used in calculations I made with regard to the leeway made by the Vertical Stabilizer, and can be found in the old AF447 thread.

Now you could go and seek out the NOAA-OSCAR surface current data for 5 and 10 June 2010 and see how it compares with the drifters above. You'll be surprised.

mm43

mm43

I think we are furiously agreeing that the currents in this area are highly variable, and that any backtracking calculation will inevitably carry a large amount of uncertainty. Certainly the actual observed currents bear little relationship to the low resolution charts showing a NE current. I am not surprised about the disparity here - I have repeatedly tried to make the point that these charts can't be used.

What we do have is:
a) 8 boys dropped in a box around the LKP on June 4
b) in the order of 100km drift west as soon as the buoys were dropped. At the likely speed of the current (and the tracks are not time stamped), this may represent 2 days drift to the west.
c) many of the buoys then turned north - probably around June 6.
d) a fair way north of here, we then had bodies tracking pretty much due north from June 6 to June 10.

What happened before June 4? Who knows. The NOAA charts sure as hell can't tell us.

Do you have time stamped data for these charts? Does the turn to the north (from this graph, many of the buoys did turn north after heading west) fit with the time when we know the bodies were drifting north? That would be interesting to know. If the buoys and the bodies were drifting north at the same time, then it is probable that they were drifting generally west at the same time.

Anyway, the total OBSERVED drift of the bodies was to the north and likely also to the west.

It would be fairly unlikely (although of course certainly not impossible) that the drift in the first 4 days was in an opposite direction and of sufficient magnitude to totally offset this subsequent drift. Hence it is fairly likely that the total drift (OBSERVED and NON-OBSERVED) was to the NW. And hence the impact point is somewhere to the SE. How far away is anyones guess. I can't state it any more clearly than that.

Slats11

You missed the point. The buoy drop was a year and 3 days after the accident which happened on 01 June 2009. The only relevancy is the time of the year, but that's as far as it goes.

mm43

Sorry - I did miss that. I assumed you were presenting data from the time of the accident. So ignore much of what I said. :\:\

What datum buoy information from the time (ie during the SAR phase) has been made publicly available?

Very little. I've seen some, but they're as relevant as the lot above.

The North Brazil Counter Current provides the NW push into the LKP 40NM radius circle, and at some point the North Atlantic Equatorial Counter Current forces a turn to the North. The Brazilian current does that (turns north) and around 4N backs to the west, while the Counter Current veers to the east. The whole thing is extremely fluid (no pun intended!) and the if, where, when and how are very much a lottery.

Its the complex geophysical forces in the equatorial region that are stretching the known boundaries. Backtracking in theory should be easier than forecasting, as you have the immediate past environmental history to work with. In this case its knowing how to apply the history that's the killer.

mm43

I agree that is the general pattern. The obvious problem is that there is no way of knowing exactly where these currents change - in either direction or magnitude.

However I think we agree that the bodies likely drifted NE or N or NW for most of the time before they were found. This means the impact point is a fair way south of where the bodies were first found. I don't think we can be more specific than this.

So I wonder why the search area has been so far north - north even of the first bodies found. On the basis of drift analysis alone, this is hard to understand. Presumably those responsible have access to other information that points elsewhere. And I am sure that all the information available is somewhat contradictory and doesn't all point to the same spot. It would however be interesting to know what this other information was.

slats11, on pdf p. 18 (of 35) of the BEA document NeoFit linked to, (thanks for the link) the blue line shows quite precisely the cumulative boundary of the aerial searches flown by Brazil and France through June 5, 2009 in the area of the last known position. Again, if large pieces of the wreckage, e.g., the VS, were in this area prior to drifting north or west and being located and recovered, they were missed.

Thus for your theory based on takata's original hypothesis -- while I can't speak for him and I don't believe he has posted on this thread in many months, even he backed off his hypothesis if I recall correctly -- to be credible, the Brazilian and French search was very inadequate, if not incompetent, to have missed such large objects.

I am sure they did the best they could, but I think we have to be careful assuming the aerial search would have found whatever was there to be seen. The effectiveness of the search would have been compromised by many factors.

We know the bodies were well within this blue line as of June 5. That is beyond doubt. And they were not found until June 6. So they missed 50-odd bodies. What else did they miss?

We must be very careful not to close off any possibilities prematurely. I think there is a real risk of doing so if we make assumptions based on what was not see where during the aerial search phase.

The aerial search may well have ultimately been more useful if they had dropped more datum buoys as soon as possible. Then drift analysis would be based on real data rather than conjecture. Of course it was a SAR mission at that time, and the focus was understandably looking for possible survivors. Not on obtaining current data.

That was also my impression.
The drift of the bodies represented a rather sharply shaped Funnel.

What I don't understand:
Why wasn't the First Search performed in an opposite direction funnel shape of let's say 20 -30° either side beginning around the first body found going opposite direction of the center of the body drift funnel i.e. pretty much south from there.
From my point of view it is not extremely probable that the drift direction during the first six days was in a completely different direction and the bodies still being rather close to each other after June 6th.
You see it with the buoys.
When the direction changes dramatically the drifting objects won't end up close together.
The bodies being relatively close together after 10 days points to a rather constant drift for me.
Yes that would not be a really systematic box search, but if you lost some personal papers and found some in the shape the bodies were found, how would you search for them ?

regards,
henra

Morbid...please refocus!
 

This thread is MORBID. Why not exercise your minds as to the timely intervention of both the aircraft maker and the authorities as to the issues with the pitot equipment.

So that means you basically accept that if the pitots on an airliner fail it is OK for it to drop out of the sky ????
That is not seriously your take on this accident ?!

It has to be found out why after the assumed failure of the pitots it ended up where it did and what can be done in future to prevent this - be it by design improvements or training or whatever comes out of it should the boxes ever be found.

There will always be the possibility that the pitots will freeze. We will probably not be able to totally convince mother nature of not ever doing that again to any airliner.

The backward drift analysis graphic is on pdf p. 24 of the BEA PPT presentation.

http://www.asso-af447.fr/images/docs...bre%202010.pdf

I believe the ACARS triangle marks the LNP.

On the graphic on p. 18, I believe the dot marked MF2 is the Meteo France calculation of the most likely impact point. As can be seen, it is to the left of the leftmost boundary of the search grids flown through June 5. I believe the grid that came closest to this point was the first day's search.

The Meteo France estimate of the impact point (at least that's what I assume it represents) is more clearly displayed on p. 14.
________________________

As to why initial search grids focused on the right of the track, I've not seen an explanation. Perhaps, the Mesoscale Convective System was drifting west to east, and if there had been an in-flight breakup, winds would have carried parts of the plane to the east. Perhaps, ATLANTICO noted that AF 459 following had ultimately deviated to the right when encountering the same MCS, and thought AF 447 might have done similar. When debris was spotted on the second and third days well to the south and east of the track and LNP, search efforts were concentrated there until the sightings proved to be false.

Pragmatism
 

They have not got a hope in hell of finding the pitot tube.

They do have a hope in hell of avoiding the issue that faults were know and not addressed promptly.

Some of you guys are obsessed with bodies and body parts. refocus you minds on the pitot issues.

All this serach will do will prolong the litigation by Air France and the relatives through the courts. I find this morbid discussion offensive.

Well DERG, if the bodies can be tracked back to where they came from, then it follows that the pitos will be in close proximicy. Since the subject of this thread is the search for AF447, I think the recent posting(s) has been right on point.