Thanks for the posted link jimjim1.
Just a couple of tidbits that jumped out at me...
The search for the wreckage was continued using side scan sonar, a system of using sound reflections to record the presence of objects on the sea bottom. To achieve this in the ocean depths in the accident area a cable of 9 kilometres long was required to tow the sonar near the ocean bottom. The equipment again is highly specialised and brought its own logistical problems. It was this equipment that located the sea bottom wreckage.
The conditions under which the search was conducted were beyond the designed situation for this type of search. The consequence was a large number of false alarms. Of the total number of pinger like sources that were recorded, 32 had to be considered, of which 13 could not be rejected as possible actual pingers.
They give you hope for even after the recorder pinger batteries fail, but also point out "false alarms" which were not something I had ever considered.
This was in 1987, I am hoping that the newer equipment for detecting the pings and advances in side scan sonar give the current searchers a bit more to work with.