Recently
GreatBear produced a graphic showing amongst others, the areas searched using Towed Pinger Locators (TPL) of the US Navy and deployed from the Anchor Handling Tugs (AHT) "Fairmount Expedition" and "Fairmont Glacier" and also the areas searched by the Nuclear Attack Submarine (SNA) "Emeraude" using her inbuilt sonar detection equipment housed in the Sonar Dome. At the time, there were no signals detected by either means, but midway through the recent extended Phase 3 Search by the "Seabed Worker" using REMUS Autonomus Underwater Vehicles (AUV) equipped with sidescan sonar (SSS), the French Ministry of Defence reported that Thales (makers of the missing aircraft's pitot tubes) had reanalyised the "Emeraude" data and were of the opinion that pinger chirps had been recorded when the sub visited an area about 40NM WSW of the Last Known Position (LKP).
The "Seabed Worker" was diverted from her predetermined search area and the aforementioned area was searched - to no avail. There appeared to be some infighting between the MoD and the BEA, but back here in this thread
Hyperveloce and others postulated that there could have been ducted ULB signals recorded that arrived by reflecting off sheer faces or bowl like geophysical structures and on being refracted when passing through a salinity inversion layer became trapped. For ease of locating, I have named that bathymetric feature L'Emeraude Range in the following graphic.
Also shown in the graphic is the initial aerial grid search box that the Brazilian Air Force (FAB) made on 01 June 2009 from 10NM before the LKP and to 10NM either side of the track to TASIL. On 02 June 2009 the FAB made further aerial searches in the box to the east of the LKP to TASIL track and likewise in a similar box to the north of that shown. The area bordered in white has not been surveyed using SSS, while nearly all of that area to the west of the SW corner of the aerial search box was initially searched by the "Emeraude" using her sonar detectors.
SaturnV has also posted graphics showing areas searched by the Brazilian Air Force and Navy along with French Naval assistance.
I'll leave you to draw your own conclusions as to where the a/c crashed, but bear in mind that the first body was found a little east of north and about 40NM from the LKP on 6 June - 5.5 days after the crash, and any areas not searched west of the LKP could be likely candidates.
mm43