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AF447

Old 5th Jan 2010, 21:50
  #4581 (permalink)  
 
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Question

I have just read through as much of this thread as I could but I couldn't find an 'end point' for a couple of the many hypotheses raised. If anyone has the patient could they remind me of the general conclusion/most probable situation regarding,

a) the availability of attitude information to the crew
b)the time taken for a 'deep stalled' descent to gl from 37k ft
c) whether a stable configuration in stall for such a period is likely in very turbulent conditions and with an aware crew ?
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Old 7th Jan 2010, 00:15
  #4582 (permalink)  
 
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Mr Optimistic, for a quick stab at B I believe that many objects share a common terminal velocity free-falling in air of about 100-140 MPH. That's about 176 feet per second. That means it's about 3.5 minutes from 37k' to surface. It'll likely be faster at really high altitudes than at sea level. So even a plane in a dead stall condition falling like a leaf MIGHT go down at about that rate.

Are you volunteering to give it a try of somebody pays for the airplane in which to try it?

{^_-} At least that's a bogey number to play around with. The real question is what might make the plane stay in such a stall given its wing configuration?
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Old 7th Jan 2010, 12:37
  #4583 (permalink)  
 
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JD-EE

a) thanks
b) no !

Was interested in what had been deduced from the stated impact configuration which I understood to be an attitude consistent with flight except of course for the velocity vector (downwards with small fwd component) which, I believe (no expert), implies well into a stall and no usable flow to engines.

Couldn't find a scenario in this thread which, given the awful situation, explained to a non-pilot how this configuration could be achieved (eg avoiding structural breakup) considering the elapsing time to 'try something' even if perhaps hopeless and eventually unsuccessful.

There was a whole string of posts on the availability of attitude data to the crew. I presumed that the impact configuration means that there must have been information to the crew otherwise such a configuration is unlikely if by chance/uncontrollable events, alone ?
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Old 7th Jan 2010, 16:04
  #4584 (permalink)  
 
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RE: Questions

Mr Optimistic (5th january):
a) the availability of attitude information to the crew
Just in case you have missed this 'Finding' in BEA's 2nd Interim Report:
None of the messages present in the CFR indicate loss of displays or inertial information (attitudes);
b)the time taken for a 'deep stalled' descent to gl from 37k ft
Although not 'deep stalled', it may be of interest that D.P.Davies' excellent book 'Handling the big jets' contains an emergency descent profile for (an early model of) the B747 from 30k ft to 15k ft in 2min10sec. Elsewhere in his book (dated 1967) he writes : "some aeroplanes will achieve descent rates of up to 14,000 ft. per minute, and 9,000 ft. per minute is quite common". Mr. Davies was Chief Test Pilot for the ARB, the predecessor of CAA, the U.K. civil aviation regulatory agency.

Regards,
HN39

Last edited by HazelNuts39; 8th Jan 2010 at 16:04. Reason: typo in 1st line, last 2 sentences added
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Old 21st Feb 2010, 17:21
  #4585 (permalink)  
 
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ITCZ WX versus Track Deviations - 01 June 2009

A few days ago when searching the BEA site for information on the Phase 3 search, I found an animation showing the tracks of a number of aircraft that flew northbound on either UN873 or UN866 between 0000z and 0300z. The animation was designed as a web application and for those using Firefox 3.5+ it can be found at -

Flight Paths of Flight AF 447 and of the flights that crossed the zone around the same time

The above animation shows a/c positions every 2.5 minutes (except AF447 - every 10 minutes), and uses Scalable Vector Graphics which allow the integration of 12 satellite images taken over the same 3 hour period. Individual aircraft/tracks can be selected, and the animation can be paused at any time.

Unfortunately, the application doesn't work in Internet Explorer, Chrome, Safari or Opera. All is not lost, as further trawling of the BEA website revealed that a video had been made of the above, and though it doesn't provide the user interaction mentioned in the preceding paragraph, it can be paused. The video will play in the Windows Media Player and is at -

http://www.bea.aero/en/enquetes/flig...ires010609.avi

This post is duplicated on the AF447 and AF447 Search to Resume threads as a matter of record.

mm43

Last edited by mm43; 22nd Feb 2010 at 01:04.
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Old 22nd Feb 2010, 14:00
  #4586 (permalink)  
 
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Interesting, the AF449 path is the most significant, IMO, same track with lots of deviations.... presumably weather...??

Bye, Barry
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Old 22nd Feb 2010, 16:05
  #4587 (permalink)  
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I am beginning to wonder if the flight crew became incapacitated. How truly sad this is.
I pray they can somehow find the CVR and FDR soon and lav to rest this terrible mystery.
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Old 25th Feb 2010, 10:48
  #4588 (permalink)  
 
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Ocean models refined to aid new AF447 wreckage search

paraphrased from the "Flight" article...

French investigators have detailed initial plans for a third attempt to find the wreckage and flight recorders

additional data, better estimates of currents and drift effects

zone will be optimised and revised once the operation starts in mid-March

two search vessels - one from Norway's Seabed Group and the other from US underwater engineering specialist Phoenix International - have been recruited for the attempt

So, they have not given up.

ref: Ocean models refined to aid new AF447 wreckage search
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Old 25th Feb 2010, 16:10
  #4589 (permalink)  
 
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Ever Seen a Flat Spin?

I removed this from R&N to post here. This follows my prior post that spinning is not required for a flat spin, for which I was humiliated. That's an oxymoron, of course.
-------

Ever Seen a Flat Spin?

I'd wager not many people have been eyewitness to a flat spin. This tale is about an F-106 Delta Dart that was in a practice dogfight:

... I took them straight up at about 38,000 ft. We got into a vertical rolling scissors. I gave him a high G rudder reversal. He tried to stay with me, that's when he lost it. He got into a post stall gyration. This happens just prior to a stall. The aircraft violently rolls left and right and sometimes swaps ends, a very violent maneuver. His recovery attempt was unsuccessful and the aircraft stalled and went into a flat spin which is usually unrecoverable.

The aircraft looked like the pitot tube was stationary with the aircraft rotating around it. Very flat and rotating quite slowly. Well,. Gary rode it down to about 15,000 feet...
This seems to describe the circumstance of AF447.

In the F-106 case, the pilot set the controls per procedure and bailed out. The plane then recovered from the flat spin and landed itself. It was repaired and returned to service, forever after known as the "Cornfield Bomber."

F-106 Delta Dart - 58-0787 Pilotless Landing
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Old 23rd Jul 2010, 10:15
  #4590 (permalink)  
 
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AF447 FDR Boxes

Just Reading A News Item Says Boxes Are In Acertain Area Pings Were Heard By Sub Last Year Updated Equipt Has Located The Area Hpe They Can Recover
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Old 9th Apr 2011, 01:26
  #4591 (permalink)  
747 forever
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Hey guys check this out, Sea search ops : wreckage images
sorry if it has been posted before
 
Old 9th Apr 2011, 10:54
  #4592 (permalink)  
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I really don't think we need two large threads on this subject.

It would be too difficult to merge the two threads so I'll lock this one and put a link in the other thread.
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