Latest positions follow:-
21 May 2010 16:35 Hdg 198.5 Spd 10.5 3°13'34"N 31°11'59"W
21 May 2010 06:02 Hdg 245.2 Spd 01.8 3°10'04"N 30°48'55"W
21 May 2010 04:23 Hdg 258.6 Spd 01.0 3°10'51"N 30°50'10"W
20 May 2010 19:36 Hdg 125.4 Spd 01.3 3°09'08"N 30°48'28"W
Note:: Not all have been plotted, and it seems that the area to the east they have been working on is now complete and the Seabed Worker is now engaged in tending her AUVs in the remaining area to the west.
HarryMann wrote in part ....
... maybe 'blue sky' thinking is inappropriate ...
Sometimes the "blinkers" go on and subsequent knowledge gets tainted by the "already known". In this particular case:-
KNOWN
1.. A position sent at 02:10:30z.
2.. A number of ACARS messages indicative of an upset.
3.. The location and condition of found bodies and debris.
4.. Aircraft impacted the ocean in an intact condition [BEA].
5.. No reported tell-tale signs of overspeed damage to aerofoil surfaces recovered.
6.. Satellite data, e.g. MeteoSat[wx ir images], OSCAR[surface current], QuikSCAT[10m winds].
7.. Limited drifter buoy data.
8.. No pingers were detected in areas searched using USN TPLs
9.. Possible pinger detection on reanalysis of Emeraude sonar tapes.
10.. No bottom debris located during sidescan searches.
UNKNOWN
1.. Why the aircraft got into a LOC situation
2.. How long the aircraft continued flying.
3.. Where it impacted with the ocean.
So, as you can see, the "Known" is actually a lot, whereas the "Unknown" is quite small. Logic tells me that with the correct approach and open minded analysis of the "Known", methodology can be developed to narrow down a likely impact position to no more than a 5NM radius (78.5NM2).
The biggest factor in the backtracking of debris, is knowing how accurate the surface current and wind data is that you are trying to work with. That can be dealt with in this case by careful analysis of the track each individual item found will have traveled over the 12 or so days from the location of the first to that of the last. Comparison of the plotted debris path and that of the OSCAR surface current data along with the QuikSCAT wind data will allow meaningful corrections to be applied to the satellite data which can then be used to adjust the data for the earlier 6 days for which we have no surface plots.
The whole reason behind this approach is to minimise the affect that that one erroneous piece of data will have on the outcome. So rather than having lots of erratic tracks drawn all over a chart, the amalgamated smoothed lines will all lead to a near common point.
Looking at the Vertical Stabilizer which had a reasonable amount of windage affecting it, and the Port Outer Spoiler which effectively had none, it is obvious to me that a retrace of their individual tracks accounting for both current and wind where appropriate will show that at a critical point the V/S became caught in the North Brazil Current and the Spoiler headed NNE toward the Equatorial Counter Current. Every other item's position will relate in one way or another to these tracks, which in the case of the V/S can be adjusted for the windage to reveal the mean current it traveled in.
Anyway, here's hoping that this last area to be searched will reveal the hidden!
mm43