AF 447 Search to resume

[mm43]

Viewer discretion required....

I find this morbid discussion offensive.

• The families of the victims want the aircraft found.
• The BEA wants the aircraft found.
• Air France wants the aircraft found.
• Airbus wants the aircraft found.
• DERG doesn't want the aircraft found.

You are out voted, and if you find this thread offensive, why not just switch off, or go and watch another channel.

mm43

[bearfoil]

DERG

The passengers and crew are our friends, loved ones, and well met, who underwent an unspeakable horror. Out of deference, and for many reasons, we must not give up the search. It would be disrespectful, and as mm43 has stated, everyone wants to find their place and their circumstances. It is a gift they give, unasked for, but nonetheless not to be ignored. Their Spirit is at home in the Hearts of us all.

Morbid is in the eye of the beholder, and a moral judgment. There are still tears, and respectful action is the way of healing.

best,
bear

[Lonewolf_50]

Thanks for pointing that out Lonewolf.

Glad to be of some small use. The engineer in me remains interested as well.

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.

As this thread shows, you are not alone.

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.

Given that both design philosophies, in the greater scheme of things, work well enough I don't think AF 447 is a test case for "all or nothing" "one or the other" arguments at the systems design level.

A number of experienced AIRBUS drivers, in this thread and others, have pointed out how to handle that kind of aircraft in Direct Law, Alternate Law, and various systems degraded modes ... and still keep the bird flying.

That said, I confess to being a non-fan of over-automation. That isn't necessarily an FBW problem. From my experience with military aircraft, some primative and some with much of automation, the problem comes at the crew-system interface. You really have to know your system, exercise that knowledge, and keep up with all of the little technical changes and nuances. Quite literally, your life and that of your passengers/crew depends upon a detailed and deep grasp of your entire aircraft systems package. As aircraft get more complex, systems-wise, the demand for this knowledge goes up, not down. As automation increases and FE's are no longer crew members, the systems knowledge requirement on the cockpit crew is (as I see it) increased.

What concerns many professional pilots is both the unknown bugs in automated control systems, and where both known and unknown points of failure in a system are.

The latter strikes me as the key driver to finding AF 447s FDR and CVR.

• What the heck was going on in those last doomed minutes?
• What actually went wrong?
• What actually wasn't working as advertised?
• Why wasn't the upset, whatever it was, recoverable?

If Airbus and various regulating agencies and airlines guess WRONG on what went wrong, then whatever fix is agreed can't prevent the next upset from a similar cause resulting in similar tragedy. **

That prospect bugs me, even though I rarely fly (separate issue) as a passenger anymore. I would hate to see AF 447 repeated because the system wasn't sure of what to fix.

@ DERG

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

You may be right.

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

Without data, the system can guess, at best. See my point above, the one with ** at the end.

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

You are assuming a solution in absence of data. That doesn't answer the questions required to put proper remedy in place for this mishap's causal factors.

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

So what?

Just because lawyers and lawsuits are a tasteless feature of modern life does not mean that problem solving should not go on. You can't hope to find the boxes if you can't figure out where the plane actually hit the water, which is still an unknown. Hence, the discussion of drift patterns to establish one or more datum from which to search for the last bits of AF 447.

Not sure your "blinders on" approach is how the industry ought to proceed, sir.

[JD-EE]

Wes wall and DERG, I see a straw man being demolished here. Who is looking for the pitot tubes? Who is silly enough to think they'll still be in the same condition as they were at the instant the plane died or entered its upset, your choice?

The object is to backtrack well enough to be able to go down there, locate some major
piece of debris, and from there search for the locations of the two important recorders, nothing else.

Obfuscating the discussion does no good.

[promani]

Revision of some theories and facts

I have kept quiet for so long, because I do not have the knowledge that some of you guys have. But after having read some posts, I thought I may be allowed to ask one or two questions. I have kept up to date with all posts in this and the previous threads, but I thought that maybe it would be a good idea just to refresh the minds of some of us of what we know and deduce so far. Obviously we all want to know what happened between 01.35.43 and 02.14 on June 1 2009.
1.Can someone tell me why AF447 did not give estimates at Tasil? These were experienced flight crew, the captain and FO having 16/39 rotations respectively on the S.America routes.
2.Is it the norm to give Tasil when ACC-AO asked for it, or was ACC-AO premature? Do we know who was communicating with ATC?
3.According to AF flight plan, AF447 should have been at SALPO M082F370/ORARO M082F370. But ACC-AO told them to maintain F350. I wonder why and whether that had any significance to what followed. 4.Were they on flight path at ORARO as it looks like they were beginning to go west and were already behind schedule as they had not reached ORARO at 0200, so maybe they were no longer M0.82?
5. I am sure I read somewhere that AF447 tried to contact DAKAR without success, but the BEA report states that there was no radio contact made between AF447 and DAKAR. Automated?
I am one of those who believe that AF447 did not travel very far after LKP, as the last ACARS was received at 02.14.26. That is only about 4 minutes after LKP, and it was already on its way down. My ten cents worth of guessing is that those poor folks met their demise NE of LKP.
Pollution spot, just some passing ship dumping. No one will own up to doing that.
Hopefully we will find the truth in 3/4 months.
Pete

[mm43]

Promani

Can someone tell me why AF447 did not give estimates at Tasil?

They provided estimates for SALPU and ORARO at INTOL. Following a SECAL check, they appear to have switched to secal watch immediately. ATLANTICO called them 3 times for the TASIL estimate, but for some unknown reason failed to SELCAL them.

I remember observing HF protocol of others using that airway shortly after the event, and found most flights only gave an estimate for TASIL when passing INTOL. On occasion ATLANTICO asked for SALPU or ORARO, but probably due to expected crossing traffic.

Do we know who was communicating with ATC?

Not 100% sure, but I believe that the Captain's voice was identified doing comms at INTOL. This may indicate that the 2/O was in the RH seat, and had produced the estimates.They filed for FL370, but didn't request higher.

Were they on flight path at ORARO as it looks like they were beginning to go west and were already behind schedule as they had not reached ORARO at 0200, so maybe they were no longer M0.82?

Tracking data indicates they passed overhead ORARO at 02:03:50 and were maintaining M0.82. Exactly when the deviation left of track occurred is not known. My supposition is that it was a result of an upset.

I am sure I read somewhere that AF447 tried to contact DAKAR without success, but the BEA report states that there was no radio contact made between AF447 and DAKAR.

DAKAR OCEANIC recorded a "failed log-in" on ADS-C at 0201z. The failure was due to DAKAR not receiving a flight plan, and the system was programed not to accept non validated flights.

Pollution spot, just some passing ship dumping. No one will own up to doing that.

Kerosene disperses and evaporates fairly quickly, but with the quantities involved it could have persisted for 48 hours or more. Heavier marine diesel and bunker fuels hang around for a lot longer, and the radar image didn't represent the typical signature made by either gland leakage or deliberate overboard discharge from a ship.

mm43

[CONF iture]

Originally Posted by Lonewolf_50

You really have to know your system, exercise that knowledge, and keep up with all of the little technical changes and nuances. Quite literally, your life and that of your passengers/crew depends upon a detailed and deep grasp of your entire aircraft systems package. As aircraft get more complex, systems-wise, the demand for this knowledge goes up, not down.

Paradox is the Manufacturer wants you to know the bare minimum – Always go back to the Mr Ziegler’s concierge ...
But the airplane is so complex when you start scratching the surface. Official reports bring more information than FCOMs, especially if they are not under the BEA leadership.

[promani]

mm43

Many thanks for your answers.

[auv-ee]

Polllution spot

Originally Posted by mm43

Kerosene disperses and evaporates fairly quickly, but with the quantities involved it could have persisted for 48 hours or more. Heavier marine diesel and bunker fuels hang around for a lot longer, and the radar image didn't represent the typical signature made by either gland leakage or deliberate overboard discharge from a ship.

I know that is has been said that the pollution spot was only imaged once (and therefore there is no tracking history available). However, does anyone know if the absence of a second image is simply a matter of orbit geometry, light angle, etc. or could the lack of a second image mean that the spot had evaporated by the time of the next imaging opportunity? If the latter, then it would support the possibility of kerosene.

[mm43]

auv-ee,

At the time I tried to find a later pass that covered the area, and couldn't. There was just one satellite in that series in operation, so the answer is: it was orbit geometry that precluded another pass. I think the group dealing with it also had no success in finding another pass.

mm43

[slats11]

Hi DERG

faults were know

1. I don't think that we know very much about what really went wrong. We have a fair suspicion that the initial problem was with the pitot tubes. But we do not know this for certain - we do not have proof of this. There have been many instances when what we initially "knew' didn't fit with the facts when they subsequently emerged.
2. Even if we accept the problem was with the pitot tubes (and I accept that this appears likely), there are a lot of links between that event and the catastrophic loss of the aircraft and all aboard. We need to learn something about that. That requires a look at the wreckage, and the recorders if that is possible.
3. I understand that talk about bodies can appear callous to some. I sincerely apologise for my role in that discussion if it is has offended or otherwise upset you or anyone else. There have been several private discussions about those that died on AF447 where much more graphic information has been discussed. Those involved have made a decision that such discussions do not belong in such a public forum as this list. As with all things, a balance needs to be found between exchanging information which may collectively help find the wreckage, and avoiding unduly upsetting others.
4. Mortui Vivos Docent. The Dead teach the Living. That will be very true here if we are able to find the wreckage of AF447.
5. The 228 people that died are owed the truth. Their families, friends and colleagues are owed the truth. The wider traveling public is owed the truth. Those that died are owed a more deserving epitaph that "We gave up and moved on"

Regards

slats11

[DERG]

Death

I no longer go to funerals. I would be grateful if you could refer to body parts as DEBRIS.

Does it never occur to you guys that oceans have life forms that eat body parts?

If they find the black boxes it will be a miracle. The way that Airbus responded to the issues with pitot tubes was dispicable.

[slats11]

Hi Henra

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

The close proximity of the bodies makes it less likely that they were subject to significant changes in current direction than if they had been widely separated. Changes in current direction would be likely to have produced more spread that we have seen here. Simply because changes in current will not be uniform and therefore generally act to create dispersion.

The buoy data that was posted a couple of days back does demonstrate this. Separation increased with each change of current. Admittedly these buoys were widely separated from the outset, and therefore were prone to further separation with changes in currents. It is a positive feedback thing - separation encourages further separation with changes in current because these changes are not uniform. However even closely grouped objects will disperse with changes in current.

Thus even though the bodies all entered the water at the same time and place, their close proximity through days 6 to 10 does then tend to argue against extensive changes in currents prior to discovery. Which argues for a simple rather than a complex backtracking model - although one which will inevitably produce a large circle where it is "most probable that the impact took place" rather than a single point.

[JD-EE]

DERG, if you are so blasted sensitive you really should not be here. I hope you know that because I for one am callous enough to ignore your sensitivities and not let them shut down this whole group. I \don't expect others here to honor your sensitivities, either. There are other fora that may be more to your taste.

[Sam Asama]

DERG

For God's sake, get a grip.

You initially wrote that mention of body parts was "morbid". Now you have posted that they should be called "debris". How disrespectful is that?

More importantly, you just now wrote about body parts being eaten -- which is exactly the type of "morbid" comment that the rest of us have avoided. Truly bizarre.

Sam

[Mr Optimistic]

wind v currents

If I have missed this, my apologies. However, given the uncertain stability of the currents, is the wind information more reliable ? What I was wondering is that if some debris like the galley section floated well clear, then a model based on backtracking that part back down the wind vector only might be interesting, ie ignore the effect of currents.

[wes_wall]

I too have pondered what result marrying the two (bodies and other) or multiple items might reveal if treated separately using only wind, only current, and then both. Any result revealing a close conclusion may indicate a likely starting point.

[SaturnV]

On pdf p. 24, of this document,

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

there is a plotting graph of a reverse drift simulation of body #3z, showing the different origin points depending on whether the body was 40%, 50%, 70%, 80%, 90% or 100 percent immersed. The different origin points span about 20 minutes of longitude, and the maximum distance traveled from simulated origin to recovery was nearly one degree of longitude.

[GreatBear]

Phase 4: Backdrift Calcs vs. Other Known Data

As mm43 has pointed out many times, the surface currents of the equatorial Atlantic in the region where AF447 went down are highly variable and difficult to predict. Test buoys dropped and followed a year later were not helpful; BEA's very smart Drift Group pointed to areas that yielded no joy during the Phase 3 ROV/AUV effort.

If you approach the impact location problem from another angle, simply using the reported LKP at 02:10 and the cotemporaneous ACARS cascade, you are correctly applying Occam's Razor. The aircraft was in normal cruise until the LKP (see my June Post #1178 and diagram). If upset was at 02:10 (or a little before), the aircraft simply could not have traveled anywhere near to the edge of a 40nm radius of interest (see Post #1349) in 4 minutes of rapidly descending and assumedly uncontrolled flight. You would conclude that the hull will be found close-in to the LKP.

The areas immediately beneath the LKP and southeastward a few km towards the slick have not yet been searched.

I do hope they start there.

GB

[slats11]

As far as I can follow it, the BEA drift group (who as you would expect have done the most sophisticated drift analysis) have attempted a composite wind and current analysis. They mention the galley (which would have been wind affected) as well as a body at varying % submerged (with varying wind effect). I am unclear what they mean when the chart is titled "Example of reverse-drift simulation". Is this one of their actual solutions for AF447, or is it simply a theoretical example? They seem to suggest that the initial drift would have been to the S or SE - is this why they have been looking so far north?

Anyway, whatever this particular graph represents they have certainly attempted to incorporate both components (wind and current). Despite the sophistication of this analysis, there are a lot of unknowns, estimates and assumptions that would have gone into this. So we may have a very sophisticated analysis of incorrect inputs. And so the solution may be completely wrong - despite all the effort that went into this.

I believe that the only chance for drift analysis to give a meaningful answer is to be highly selective about what information is put into the model. Look for the purest signal and use the simplest model. Discard all the random noise - no one can know the balance of wind versus current for much of the debris. More data is not always better.

So we are back to the bodies - relying on the fact that we have 50 similar objects, and they will be almost entirely current affected and so we can eliminate the wind as a variable.

Takata and Fluid Flow have both adopted this approach for these very reasons. They have both come up with an impact point to the south. Takata assumed a constant current for 5 days prior to discovery (obviously a major assumption), which put the wreckage well to the south. Fluid Flow applied a regression analysis to the same data, and came up with a much closer point but in the same direction. This position is more likely than Takata's for three reasons:
a) it is hard to understand how the plane ended up as far south as Takata determined. It is even harder to imagine that it would have done so without their being some communication from the plane.
b) FluidFlow's answer incorporates the pollution spot (naturally, as he used this datum in this analysis)
c) Fluid Flow's solution also satisfies GreatBear's contention that the aircraft can't be very far from LKP.

One minor unknown in the body drift analysis. We know the date and location, but don't know the time of day that the body was discovered. Takata indicated that the first body found on June 6 was found at 0900Z. However he did not indicate the time that the bodies were discovered on subsequent days. He appeared to use the northernmost body and reverted to days (7,8,9 and 10 June). This detailed information may not be in the public domain. Knowing this information might smooth out some of this data and help refine the solution. We can probably assume they were found during daylight only - searching for bodies over an open ocean is a daylight task. We will have to assume a time if this information is not available. 1400Z (ie noon local time which would be close to the middle of the search period each day) is probably the best time to use. This will be closer to reality than assuming 2400Z. I don't know what Takata did for the locations on the subsequent days. He may have kept using 0900Z so he was working in 24 hr increments, or he may have used 0000 (the start of the day) or 2400 (the end of the day). In the absence of information, he had to make some assumption. Whatever assumption he made will have influenced his estimate of the average current speed.

The other refinement to Takata's analysis would be to use some form of "average" position for that day rather than the northernmost body. As will as being statistically more correct than relying on the extreme (most northern) datum each day, this would tie in with using 1400Z as the average time found for that day. This would reduce his estimated strength of the current, which would bring his impact point somewhere north of 2N (perhaps close to FluidFlow's solution).

If anyone has the raw data of the locations and the discovery times of the individual bodies, it would be interesting to play around with this.