joker97: Hope you're right ... lemme go watch some CNN :D

oxnsox: These are Acoustic signals not RF, and the salt water salinity, temperature, and subsurface geography means they don't behave quite like RF.

But as you've said there's good maths and smart folks well used to interpreting this stuff ( military and oil industry) so the skills and tools are o
available.

frankv: All the calculations people are suggesting to find the pingers seem to assume an unimpeded path between the pinger and listener (some people have also mentioned refraction, etc). But the sea floor isn't flat, and (where the topography is pointy) things fall to the bottom of troughs rather than perch conveniently on summits.

So the range of the pingers may be quite limited horizontally, in one or more directions.

FWIW, here's bathymetry of the area: http://www.deepreef.org/biography/robs-blog/155-zenith.html

The comments "the gentle sloping seafloor, (apparently) limited finer-scale topographic relief and the soft sediment nature of the seafloor" suggest that the search for the pinger locations a bit easier than it might have been.

frankv: Another factor... does a 777 autopilot maintain a heading relative to the Earth's magnetic field, or based on INS? Or does it maintain a specified ground track, which would be unaffected by winds?

franky:  I guess that a Great Circle flight path indicates that probably the flight director was flying the aircraft, although its possible that it was a person. In either case, the intention was take the aircraft to(wards) somewhere specific, a long way away. OTOH, a Rhumb Line suggests that the aircraft was probably being flown by the auto-pilot, and either it wasn't going anywhere specific, or it was intended for a short distance. So, if we know what type of flight path was followed, we have an indication of what the pilot intended, which is one of the unknowns about this flight.