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AF447

Old 13th Jun 2009, 19:15
  #1381 (permalink)  
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Originally Posted by RuudA View Post
The Brazilian Air Force released information on 9 June showing that bodies from flight af447 had been recovered from locations that were more than 50 miles apart..

. . can also be explained by the influence of the surface current: the Northern South Equatorial Current (NSEC).

This NSEC current is a westward flowing current that extends from the surface to a nominal depth of 100 m.
As I tried to post before, but it was deleted, the surface current moderated by the wind, will account for a significant distance between the point that debris entered the current and the point at which it was found.

The significant point in RuudA's post is surface. Debris is more likely to be released from the wreckage as the aircraft descends and breaks up at depth. Such debris will be affected by sub-surface currents until such time as it rises to the surface current zone.

There is no guarantee that all sub-surface release will occur at the same time or the same depth. It is as likely that the debris spread is from sub-surface release as from an airborne breakup.

PS, I believe this post-crash surfacing of debris was a feature of a RNlN Atlantic aircraft about 30 years ago.
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Old 13th Jun 2009, 19:26
  #1382 (permalink)  
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It seems to me that where these threads go wrong is when someone fixates on a single fact.

A single fact can disprove a theory, but it can never prove a theory. And a theory is only viable when it accounts for all the facts known.

An example: It was noted previously (multiple times - I'm not specifically responding to the immediately preceding posts) that the dispersal of the remains is not firm evidence of an in-flight breakup, because ocean currents could also play a role in the dispersal, or even account for it completely.

As far it goes that is reasonable. But it ignores other reported evidence - e.g. ocean currents do not account for the reports that some victims had all clothing ripped off, or had ceased to breath by the time they encountered water (no water in lungs).

But those other data points themselves do not "prove" in-flight breakup either. Other explanations are still open.

We have pictures of a VS no longer attached to the rest of the aircraft. A data point. I see no evidence one way or the other as to when the VS ceased to be attached: At 35,000 ft? At 15,000 ft? At 0 feet?

I see a VS in which the failure point appears to be in the aluminum-alloy supports, not the composite structure - but am perfectly prepared to be corrected on that.

As far as I'm concerned, there are only four clearly established facts in this tragedy: The plane departed radar range, the flight was in the vicinity of tropical convective weather, a series of maintenance/failure messages were sent, and remains have been found on the ocean.

What occured amidst and between those knowns is still a very large black hole bespeckled with a few dots of light.
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Old 13th Jun 2009, 19:27
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I originally thought the two jumpseats were attached to an aft bulkhead (structural or otherwise) because of the seeming reduced radius apparent at the perimeter of the curved joint with Fuselage inner skin. If the structure's termination in a straight line adjacent the 'inner' seat is a 'passageway', it suggests a narrow (overall) width. The Fuselage forward does not reduce its diameter until forward of where the jumps would be.

Also, in observing the belts, it is possible they were 'adjusted' by recovery personnel, although one is doubtful that pros would in any way alter the appearance or the ability of evidence to tell a story when closely examined. I think they were well aft and near the pressure vessel's aft terminus.
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Old 13th Jun 2009, 19:30
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e.g. ocean currents do not account for the reports that some victims had all clothing ripped off
You haven't been back-reading the posts lately, have you?
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Old 13th Jun 2009, 19:34
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We have pictures of a VS no longer attached to the rest of the aircraft. A data point. I see no evidence one way or the other as to when the VS ceased to be attached: At 35,000 ft? At 15,000 ft? At 0 feet?
Or sub-surface breakup either.
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Old 13th Jun 2009, 19:36
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Harry: Well I've been trying - sometimes PPRuNe outruns me... (edit) have double-backread everything now - not sure what your point is?

Pontius: true.

Last edited by pattern_is_full; 13th Jun 2009 at 20:17.
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Old 13th Jun 2009, 19:53
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Will Fraser,
the twin jumpseats FWD have the CIDS located above them. That's why I'd say the ones shown are AFT. There doesn't seem to be a trace of the CIDS on the pictures, although it is impossible to be sure without a close examination, the pictures are not clear enough.
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Old 13th Jun 2009, 20:10
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Maximum range for the TCAS to display a target is only 40 NM ...
Iberia was probably tracking AF447 on the CDTI on ADS-B which will show aircraft well over 100 miles away.
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Old 13th Jun 2009, 20:22
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Maximum range for the TCAS to display a target is only 40 NM ...
Well, the press report is ambigous (for a change), but I also did see the Iberia pilot interviewed in a TV program.

The recap, this time in my own words is:

-They took off 7 minutes later on the A320 to follow "dead on" the tail of the AF 330

-At some point, they had TCAS contact and the captain had an eye on it to monitor, as they were sharing the route and fairly close.

-The Iberia pilot believed the AF was about 80 miles dead straight ahead when he noticed bad patch of weather coming and decided to start a change in the scheduled course and turn east some 30 miles to circunvent it (potentially leaving the AF, around 8 minutes ahead, in a course to go through this rough weather patch). He believes this coincided almost exactly when the moment the AF went "missing".

-The Iberia pilot wasn't really "afraid" for the AF when they weren't answering ATC figuring perhaps they had a transporder/communication problems as, in his opinion, there was nothing unusual at all with the weather or circunstances around the area, in spite of some "normal" rough patches. He was surprised to later find out the AF had likely crashed as he couldn't figure out a situation with such high risk of accident (at all), in spite of occasional bad weather spots. He insists circunstances were well within, and even "below", normal for the route, while not "perfect" or "great", but not unusually bad or even "strong". Just plain old bad-ish. Certainly nothing in his opinion to warrant a high risk of accident. Of course, he wants to make clear that, in the aprox. 8 minutes that separated them, the weather could've changed quite a bit as it's unpredictable, but he just can't believe it could've turned so bad as to endanger the AF to the point of catastrophy, but with the weather, everything is, of course, possible.

FWIW
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Old 13th Jun 2009, 20:32
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Possibly not probably, and easy enough to find out.
Well, then, go find out for us and report back.
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Old 13th Jun 2009, 20:46
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Good point Chu-Chu. Looked it up, the 2-liter soda bottles are good to 50 psi.
Cabin differential pressure at 35k ft is 9 psi. Can't be as confident as before, but those clear water bottles in the photo are more flimsy than the 2-litter ones. Might do a little experiment in the hangar later.
Another aspect of the water bottles is that many flight attendants intentionally don't tighten the caps when they are empty. If you do, you get an uncomfortable crackling sound as the cabin descends and bottles collapse.

Not sure you can tell much either way from the condition of those bottles. They may have been emptied at altitude, had tightened caps, partially collapsed at sea level and popped back when opened after recovery.
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Old 13th Jun 2009, 21:10
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Just asking.
Interesting item. Thinking human factors, I'm also interested in whether people who are in a broken & tumbling aircraft would, for some reason based on primal instinct, unlatch their safety belt. I know people who jump from great heights and start to tumble have a natural overpowering urge to reach out for something to stabilize them. To unlatch their safety belt would position them to be more effected by air and water currents.

Maybe all people, falling over land or sea get stripped by the air pressure or later by the ocean.
Harry Mann referred to analysis of the Comet breakups where they concluded wave action was responsible for (at least some)clothing removal. I never would've considered that before but thinking of how my water-saturated-loostened-weighted clothing behaved when I swam with clothes on, it sure clicks with me.

As to whether clothes could be removed by decompression, my personal experience with only 'rapid' decompression in an altitude chamber says no-way. As for explosive decompression and airframe breakup you MUST refer to other accidents (at altitude over dry land) where that would have been the dominate possibility and what the outcome was.

We do have a case of rapid-or-explosive decompression of a B737 near Hawaii where a flight attendent was pulled from the cabin. I saw the photos of passengers after landing and saw NO EVIDENCE or remarks of clothing removal.
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Old 13th Jun 2009, 21:10
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Pattern is full - What Harry is saying is that (prior occurrences and research have shown) there is no correlation to the remains being "clothed / unclothed" and the height (if any) from which they fell. Especially after many days in the ocean. In additon to the comments immediately above this, there are (or were) posts early in this thread discussing this point and citing sources.

All who are wondering about seatbelt positions, bottles being crumpled or not, and other thoughts related to "condition": If (and its a big "if") the people who first came into contact with items from AF447 were properly trained (or at least briefed) then many photos of each item will have been taken prior to any contact by human or machine (if at all possible). Having said that, even if it was done, in some cases it will be of little or no help, but in others it often turns out to be useful.
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Old 13th Jun 2009, 21:13
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Will be astonished if the searchers touch anything on those debris..as they are evidences ...
They had certainly be briefed for not disturb any pieces of evidence..
I agree they shouldn't do much to the debris but the items displayed in the photo op seem to have been carefully cleaned and dried for display.
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Old 13th Jun 2009, 21:20
  #1395 (permalink)  
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Originally Posted by Airbubba View Post
I agree they shouldn't do much to the debris but the items displayed in the photo op seem to have been carefully cleaned and dried for display.
as in - no salt stains.
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Old 13th Jun 2009, 21:21
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Quote from Aviation Herald:

The FAB said on Jun 13th, that a merchant ship "Gammagas" on the route from Uruguay to the United Kingdom discovered and recovered the rugged structure of the aircraft about 415km northwest of St. Peter and Paul.
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Old 13th Jun 2009, 21:33
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communications

Thanks Yaw String, Justme69 & Slotpolice for your inputs.

Wouldn't be "normal" the IB pilot try to call AF447 on open freq to advise that control is trying to reach him? Specially that control began its calls at almost the same moment AF "disapeared" from his TCAS display.

Would be important to know more about this a/c that was ahead of AF447, if he heard control calling AF 447, if he heard Iberia's deviation report...
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Old 13th Jun 2009, 21:39
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Makes one wonder on the decision discrepancy. One thought he should circunvent, the other didn't... I'm not saying the AF crew did something wrong, though... You must be there to know what's going on....But... it makes you wonder.
A set of people, even when exposed to precisely the same conditions would do different things. These crews weren't exposed to precisely the same conditions.
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Old 13th Jun 2009, 21:42
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ttcse and grizzled: Thanks. So we're still left with far too few dots to connect into a picture yet.
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Old 13th Jun 2009, 21:55
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ttcse and grizzled: Thanks. So we're still left with far too few dots to connect into a picture yet.
I see multiple vague possibilities but haven't heard of cookies or free jump-seat tickets or public recognition ceremonies being offered to the person who makes the first correct guess.
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