In aviation we have had radio direction finding equipment since at least the early days of WWII.

Low frequency radio ranges and very high frequency (VHF)ranges have been the foundation of air navigation which is now supplemented by inertial navigation systems (INS) and satellite navigation.

Maybe I am wrong, but it seems that the technology to develop a receiver that would have direction finding ability for the frequency of the black box could be developed. That would allow the searchers to home in on the signal rather quickly instead of the present system, which seems to be much like the old low frequency radio range orientation system (A procedure that took time and effort to execute.) that was used before direction finders (A compass rose with a needle that pointed at the signal.) were developed.

Maybe this accident will initiate some research into that. Maybe not.

In the continued absence of debris I maintain what I have from the beginning, that the thing never crashed. It landed somewhere, probably in China.

And with distinct navigation sights from (1) the crew directly involved in clear weather, and (2)the crews firing upon - both RMS Titanic and DKM Bismarck took some time before their very sizable wrecks were ever located.

It will be some time before that aircraft is found, and if there is ever an understanding of what happened that makes sense I doubt I (at 48) will learn it.