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AF447

Old 10th Jul 2009, 19:01
  #3441 (permalink)  
 
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flat attitude

Flat attitude
A lot of time with semantics was spent on the exact attitude
"en ligne d`vol ",flat horizontal,with very little forward speed...
With regard to the VS possibly being ripped off to tumble forward.
How stormy was it at sea level? How big the swells?
I envisage a tail down approach (not into wind, cross swell), at high attitude and hitting the back face of a swell smack on, sufficiently to break the belly in.
(Think 737 on the Motorway embankment at Derby)
With for good measure the tail cone clipping a previous swell and breaking UP
Thus striking and crushing the rudder base and catapulting it forward free of its compromised hull structure
This explains the ability of the hull to hit the water surface forcefully wth mainly 90 degree impact while still having a much more credible forward airspeed.
Of course it would stop in the water very quickly with the following swell "pooping" and washing out the now opened hull, and smashing into the back of the vulnerable spoiler(s)
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Old 10th Jul 2009, 19:45
  #3442 (permalink)  
 
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South-America line pilot experience

FanAviation:
...So the conclusion is neither the captain nor co-pilot1 ever flew to Rio. Only co-pilot2 flew there once...
I noticed that when I read the report but not being a pilot I don't know how important to the crash it could be, or not...
Hi,
May I ask you where did you read that in the report and to quote it for my better understanding, please?
(Is it that hard to verify such a claim presented as the conclusion before posting it?)

S~
Olivier
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Old 10th Jul 2009, 19:49
  #3443 (permalink)  
 
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Blimey Wilyflier - given the paucity of the information I can only say that you have a heck of an imagination!
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Old 10th Jul 2009, 20:07
  #3444 (permalink)  
 
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Hi Takata, I presume your question is about "my" conclusion and not about the facts (as you already said that the experience of the pilots was in the report...) So...
I am french (so are you as I strongly suppose...) and to a frenchman the fact they say : captain 16 rotations to SA, co-pilot1 39 rotations to SA, co-pilot2 5 rotations including 1 to Rio is the obvious (to me!) proof the others have not. Else why would they specify this fact ONLY for co-pilot2?
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Old 10th Jul 2009, 20:36
  #3445 (permalink)  
 
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Else why would they specify this fact ONLY for co-pilot2?
Maybe because with only five rotations, there might have been a slight chance he never few that route?

Remember: always go for the simplest explanation.
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Old 10th Jul 2009, 20:50
  #3446 (permalink)  
 
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Does it really matter how many times they might have flown this specific route? As we know from AF559, the route from Sao Paulo is practically identical to that AF447 followed, and any other route from the Southern cone would have crossed the ITCZ in the same general area, if not on the same path.
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Old 10th Jul 2009, 20:50
  #3447 (permalink)  
 
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takata & WilyB

I think it is obvious by the report that the Captain had plenty of experience. That is not the issue. The issue is that no one knows for sure where he was when the proverbial sh*#t hit the fan!

Apparently he may have been sleeping......

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Old 10th Jul 2009, 20:56
  #3448 (permalink)  
 
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Thanks for the detailed response L337 .

Given that all the other flights had to alter their course to avoid the weather then I think it is safe to assume that AF447 would have had to do the same thing at some point.
What is odd that from the limited data we have it appears that AF447 made no manouvering upto the point of the incident. This is remarkable given the path of the a/c when overlayed on the various satellite images.

Data points:
no pre-flight extra fuel
no known voice comms of course/altitude alterations
no known requests for extra optional weather info
no course alterations when entering the immediate vacinity of the CB cluster

Could weather avoidance manouvers have omitted for some reason and if so why?
Clearly the pitot's iced and it quickly went from bad to far worse. Other flights had experienced the pitot problem and delicately flown via N1 and attitude until the pitots cleared. Clearly there is still a piece(s) missing, a nasty updraft / losing a control surface due to inaccurate IAS / or something else to upset the a/c whilst flying with limited instruments in ALT LAW. Whatever it was it happened extremely fast to prevent any "we're down" message from the crew or from passengers via satellite phone.

Having read that the US are giving up the search, I hope that the French g'ment does whatever it takes to recover the FDR/CVR. If we can find the Titanic then we can find F-GZCP. Just because the pingers have failed the data is still there in all liklihood.

We do not want a repeat of this incident. The French g'ment needs to consider that if a similar incident happens in 12 months then they could regret not having done more this time around especially if it turns out to be an easily corrected fault.
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Old 10th Jul 2009, 21:14
  #3449 (permalink)  
 
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Hi,

Given that all the other flights had to alter their course to avoid the weather then I think it is safe to assume that AF447 would have had to do the same thing at some point.
What is odd that from the limited data we have it appears that AF447 made no manouvering upto the point of the incident. This is remarkable given the path of the a/c when overlayed on the various satellite images.
Read this when available in english (soon)

Eurocockpit - Accueil

Bye.
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Old 10th Jul 2009, 21:40
  #3450 (permalink)  
 
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This a/c did not have a 'three pilot crew'. It had two pilots and a relief pilot. Where the Captain was, if not on the FD is irrelevant, he was not PIC at the time two other qualified pilots were in the two (provided) seats. Further, my understanding is that the F/O would be PIC and flying from his (right) seat. Is that it? Because if Captain is allowed to leave the FD and catch some sleep, isn't it understood he may be unavailable, and by design? F/O also has most time in type, 4700 hours? Is this pilot thing really an issue?

edit: F/O (copilot 1) time in type/ correction 4,479 hours

Last edited by Will Fraser; 11th Jul 2009 at 03:04.
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Old 10th Jul 2009, 21:47
  #3451 (permalink)  
PJ2
 
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L337;
Safety comes first always, but it needs to be commercial as well
Succinct and absolutely correct post. Well done.

My point on this need has always been, commercial viability but with safety paramount, (and pilots realize this far better than the beancounters).

It has to work commercially. The "insurance policies" for doing this safely are:

a) highly-trained and motivated workforce,

b) leadership by, support of and defence by the CEO for expenditures on "non-profit-making" safety programs, (I know an airline that termed the Safety Department a "Profit Center" for god's sake, solely in keeping with an MBA's view of the corporate bureaucratic world) and

c) a willingness to continously examine and accept the nasty bits of aviation so they don't bite one in the ethical, corporate and legal ass, and finally,

d) an abiding, clear and firm intolerance straight from the top of the organization, for departmental trading off of commercial priorities with safety priorities. I've seen that occur and accepted as far up as the CEO; it is dangerous work when that occurs.

In other words, if the organization is concerned for it's profitability and he leadership broadcasts to employees that "cost" as the organization's biggest concern and, because survival in the bureaucracy works that way, that is precisely what department heads will begin to tell their subordinates and what they will extract from their people. Nobody wants to look bad at meetings or in the numbers. The CEO is the person to ensure that that doesn't happen.

Mudman;
If the engines flamed out as some folks have theorized would no electrical power from the engines mean that the FDR and CVR would stop working? Is there an alternate power source for them?
Correct; the FDR/CVR would stop working should the AC1 or AC2 buses lose power. It is presently an issue within the safety and regulatory community. Swissair's recorders were lost at about 6000ft due to the rapid degradation of the electrical system, most of the relays, computers and controls for which were located in the cockpit and under/cockpit area. Control of the aircraft is assumed to have been lost at that point.

Last edited by PJ2; 10th Jul 2009 at 22:06.
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Old 10th Jul 2009, 21:48
  #3452 (permalink)  
 
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Will Fraser

Point Taken......
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Old 10th Jul 2009, 23:24
  #3453 (permalink)  
 
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Quote:
Some answer about deviation (supposed) there

AF447 : comme Lufthansa, l'avion a dévié à l'Ouest de sa route prévue

A quick summary of what eurocockpit is claiming, for non-French readers:

The last reported position of AF447, at 0210Z, is actually about 3nm west of track, so it is likely that AF447 was in fact deviating to avoid weather. Given GPS etc, this discrepancy is unlikely to be due to poor navigation; nor is it an offset, as that would have placed AF447 1 nm EAST of track.

Thus they place in doubt BEA's finding that AF447 was on track, and AF CEO Gourgeon's suggestions that perhaps the crew of AF447 didn't use their wx radar appropriately.

(Before someone asks, I grew up in France and the French-speaking part of Switzerland, and I'm a pilot (albeit only PPL) and so understand aeronautical French as well as normal French)
Was F-GZCP significantly off course at the actual time of the faults (as opposed the ACARS time stamp)?
If the answer is yes then that has implications. Why was ATC/nearby a/c not notified of the course change. Obviously in an emergency flying comes first so one hypothesis would be that an emergency had already occurred prior to pitots failing.
The BEA interim report does not mention this explicitly (if it does please give page.) I did find this:
(p.68 english copy)
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,
Coincidently 0210Z was the time that ACARS alerts appeared and the controls reverted to ALTN LAW there was a GPS position reference. There is some latency which delays the maintenance reports.

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Old 10th Jul 2009, 23:24
  #3454 (permalink)  
 
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Just a couple of data points for the "what if" folks here.

Engines rarely flame-out completely but may rundown and have to be restarted. It's therfore not likley that the generators are going to be tripped off-line for all engines at the same time.

In aircraft upsets the engines often stall due to shearing of the air across the inlet. Often confirmed at low altitude as bangs and flashes of flame. I don't recall any data of such at altitude.

In most upsets at altitude wing mounted engines get slung off the wings if high yaw rates are involved. PA103, TWA800 AA587 etc.
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Old 10th Jul 2009, 23:38
  #3455 (permalink)  
 
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OGlobo now reports all victims had died on impact

Originally Posted by OGlobo of Jul 7, 2009

RIO - The number of identified victims of the Air France flight 447 suffered this new amendment Tuesday.

Representatives of the Federal Police, Office of Legal Medicine (IML) and Secretariat of Social Defense (SDS), which joined the Task Force responsible for the identification of victims of air disaster, said that an examination of DNA showed that a fragment a of body that was found at sea belonged to a body that had been collected. With this identification, the number of found victims reduced from 51 to 50.

Of these, 43 have been identified. Seven bodies in the IML still await identification, among them, the body which the fragment belonged.

According to the head of Forensic Science, Francisco Sarmento, all the bodies had multiple fractures and injuries, probably caused by the impact, which was the cause of death.

- The victims had multiple fractures, injuries and ruptures of internal organs, evidenced by impact.

- The information I can give is that the the death was caused by impact, which is characterized by the presence of polytraumatic injuries, he said.
Source: A somewhat corrected output of a Google translation of Cai de 51 para 50 número de vítimas do voo AF 447 - O Globo

So it appears a bit more likely now, that the plane came down in one piece -- not because of the impact itself, but for the cruel detail which also allowed to reduce the number of victims from 51 to 50.


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Old 10th Jul 2009, 23:49
  #3456 (permalink)  
 
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Xcitation

I hope that the French g'ment does whatever it takes to recover the FDR/CVR.
The last I read, the French attack submarine Emeraude was to search until July 10; after that unmanned minisubmarines will continue looking for whatever is left of the aircraft.
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Old 10th Jul 2009, 23:57
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Other than 'slung off', how would an engineering discussion characterize the analysis of 'failure' (engine loss from mountings) ? That is to say, there is probably a difference between 'yaw angle' and 'yaw rate' ?
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Old 11th Jul 2009, 00:29
  #3458 (permalink)  
 
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Hi,

I did find this:
(p.68 english copy)
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,
Coincidently 0210Z was the time that ACARS alerts appeared and the controls reverted to ALTN LAW there was a GPS position reference. There is some latency which delays the maintenance reports.
In waiting a translation from the original .. this is a Google translation of a extract:

For example, page 48 of the BEA report, it shows "the last position received" of 2.98 ° (2 ° 58.8 ') north and 30.59 ° (30 ° 35.4') west to 2:10 UTC.

On a map, it can easily be carried as part of the "route to the flight plan" between "ORARO and TASIL.

Between these two points, the course "right card (straight between two points on the card) is similar to circle route (corresponding to the curved line between those two points on the earth sphere). Indeed, the distance between these two points is only 119 Nm and the "arrow" (lateral deviation between the right map, and circle) is negligible over such a short distance.

The report of the position of flight AF 447 to 2:10, with the coordinates provided by the BEA, place the aircraft at about 2.9 nm west of the road.

For the curious, an official Jeppesen electronic road can be checked easily graphically.

A calculation of spherical trigonometry mathematical and precise, we wish to provide for some having doubts, gives a gap approached 2.9439071 Nm The maximum error of the accuracy of the values of position given by the BEA is 0.5 tenths degree, in one way or the other.

In other words: at 2:10, Flight AF 447 is not on the planned route in the flight plan ", as the BEA, but almost 3 Nm to the west of it.




Bye.
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Old 11th Jul 2009, 00:34
  #3459 (permalink)  
 
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447

0135 established, stable cruise, M.82 FL350

0210 a/p auto disconnect, to include A/THR and ALT LAW 2

0214 last ACARS, last anything.

UNK Entered the Sea per description by BEA

Hypotheticals:

Prior to a/p disc. the pilots noted turbulence. If so, they made a decision to allow the a/p to continue. In this case, they would have been prepared for 'handback'. If they either didn't notice turbulence, or there was none, the a/p disconnected 'suddenly' with a sudden onset of a/c response that was above programmed limits. In other words, the decision was likely made to allow the a/p to continue to fly. It would take a series of coincidences to have occurred (faults) that were simultaneous with a/p disconnect; if not, then a/p disconnect was a result of something that happened prior, e.g. pitot problems.

With Unreliable a/s, my assumption would be that Pitch would be the instantly necessary mitigation (probably to lower the nose if IAS was 'low'.) If the a/p lowered the nose to its limit then dropped out, wouldn't the 'sudden loss' of autoflight call for some time lapse for pilots to get up to 'speed'? Also, without a/p and a nose trending down, (what's to arrest the Nose Down momentum?) could the Nose be quite low, speed building rapidly, and the a/s still indicating 'low'? Overspeed alerts, low IAS, loud slipstream, a handful of other demanding issues, etc. etc.

What would AB Alt Law 2 be doing at this point relative to recovering, especially the controls, arresting overspeed, etc. What is the pilot's expectation of the a/c's behaviour, given that his own SA is limited?

edit. : LeandroSecundo In your translation it is said "the distance is only 119 nm. and the arrow is negligible over such a short distance". Wouldn't any course deviation be enhanced as distance shortens? Isn't three nm 3 degrees in 119 nm? edit. that isn't 'on course'.

Last edited by Will Fraser; 13th Jul 2009 at 14:38.
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Old 11th Jul 2009, 01:14
  #3460 (permalink)  
 
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Will

Re your comment about the 3nm displacement.

LS is, I think, not referring to the actual a/c position but to the relationship between a "straight line" on a chart, over a short distance, and the actual shortest distance (i.e. derived from a great circle or the distance as per spherical geometry). The shorter the distance the less lateral deviation between the two. The greater the distance, the greater the lateral deviation.

So it seems you are both saying the same thing: A 3nm lateral displacement over that distance (119 nm) is much more than can be accounted for by citing the differences between navigating and/or plotting positions using a straight line on a chart, or a formula that allows for navigating over a sphere (as per WGS84, GPS software, etc).
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