Hello GreatBear,
Originally Posted by GreatBear
More likely, all went bad and vertical very quickly. Shedding velocity and motion along the track, unusual attitudes, rapid descent (in a spin?), dark, stormy... Draw that circle maybe ten or fifteen nautical miles radius from the Last Known Position. BEA have not searched there yet.
In fact, this is the first place the BEA searched with its best assets (USN's dedicated TPLs = pinger locators) when the recorder's balises where still working.
You should remember that the search operation is in phase 3 and that the previous two phases were detailed in BEA 2nd report, annexe 2, p. 77-86.
In short: they defined the most probable crash zone called "Alpha zone" starting about 10 nm South of last know positition and extending to 10 nm South of Tasil. This is the black box pictured in the map below:
Each grid box is 10 x 10 nm.
When pingers stopped to work, they assessed the above "quality" map to continue into phase 2 where other means were deployed by oceanic survey vessel
Pourquoi pas? consisting of deep sonar robots (i.e. J-K-L-M 24 previously skipped boxes were searched this way). The goal was to systematically finish the Alpha zone and eventually also the 40 nm radius defined circle centered at LKP.
As you can see it now, phase 3 is completing the previous work using better reverse drift models newly developped, but they were also scanning already searched boxes having low quality scores (mostly from Emeraude's assigned zone).
Taking into account the very high probability that TPLs would have picked any signal from the recorders along the flight path to TASIL (where the relief is much more gentle), it is very probable that AF447's wreck is not located into this zone... or, if it is really there, that both pingers were destroyed during the crash.
Originally Posted by GreatBear
The upset occurred within seconds of the ACARS position report at 0210 (02:10:10 - .1/WRN/WN0906010210 221002006AUTO FLT AP OFF). Minutes later, the aircraft reported that cabin pressure couldn't keep up with ambient (02:14:26 - .1/WRN/WN0906010214 213100206ADVISORY CABIN VERTICAL SPEED). Assume the aircraft was (and had been) falling fast. But not so fast as to exceed V-tears-itself-apart: impacted water intact at high vertical speed in line of flight.
You are right considering two big 'IF'.
- If upset did take place at 0210... [nothing is telling us it did].
- If end of flight was ~0215... [there is still very good chances it was not].
About the time it could take for AF447 to go down, something as fast as 1 minute and half is possible from cruise level. Then if ~0215 was the end of flight, an upset could have occured as late as ~0214, making quite some distance between 0210 (LKP) and crash site.
Consequently, the next major step into this investigation would have to be the localization of the wreckage which, by itself, will reveal a lot more about this upset/crash sequence. Last declarations (yesterday) are telling us hoppefully that the search will not stop here and big efforts will continue until they find it.
S~
Olivier