Has anyone got any updates/details about whether there are signals from the FDR pinger locator - seems to be ignored in this thread ?!
Not really ignored but only becoming relevant now with specialized ships capable of detecting them just arriving in the area.
The civilian 37.5 kHz Undewater Locator Beacon (ULB) has a very limited range, usually only about 3 nm, maybe a bit more if sea conditions are favorable.
Mind you, the search area is now over 50,000 square miles -- roughly the same size of Greece! So comparatively you'll almost have to be "on top" of an ULB to hear its ping.
Often ULBs are more useful in locating the "black boxes"
after the general crash area has been found by other means (side-scan sonar, debris, oil slick, etc.)
Some military aircraft have low-frequency beacons (8 to 10 kHz) which can be detected from 5 to 10 miles; however, they are not yet standard on civilian aircraft.
The Java sea is shallow, so at least the helps in the logistics of hearing ULBs. (Although there is sometimes more interference in shallow water).