That's why they're trying to narrow the search area down as much as possible; they know the locator beacons will die soon, so the race is to reduce the required area to something that UAVs/AUVs can manage with reasonable chances of success.
Terrain will be a big part of the equation.
One expert mentioned that the wreckage will present sharp edges and stand out easily with sidescan sonar because the floor is all soft silt. Fortunately for experts, that meme is spinning up, gaining traction and is now getting quoted without attribution as if it were an actual fact about that area.
Ok for most of Lake Erie but just rubbish for the area in question.
Regardless of the area size and the buzzwords, in the end this is going to be a brute force search.
Expect lots of false alarms after they start.
Sidescan sonar can accurately produce an image of a sunken ship in great detail. And often does. Visual inspections typically reveal no ship at all and no easy way to wrap your head around why the sonar images didn't match reality.
Expect more of that with rough terrain.
Bottom line, lots of cross checks required.
And vehicles like the Bluefin are modular. It can carry cameras or sidescan sonar but not both at the same time.
So all sidescan sonar is really going to do is help reduce the search area.
None of the phases are going to be skipped, at least I don't see how in this case -
Surface surveys (pretty much done), pinger detection (pretty much done), sidescan sonar of the floor (not started), followed by camera surveys of *candidate* areas as indicated by sidescan sonar, followed by retrieval of *candidate* objects, followed by identification and then verification - followed by detailed wreckage retrieval after all of that pans out. And aircraft aluminum, broken into pieces, is not going to sink a few miles in a turbulent ocean and end up in one spot. Aircraft does not equal heavy ship, so that process is going to be working over a number of candidate spots.
In my opinion.
Sounds travel and hide in layers in the ocean.
There was never a realistic possibility of ping, ping, ping, ping until X marks the spot, just a hope for that.
The ping location part influences success because resources for the rest of the process are limited.
Btw - not knocking any of the skills but the pinger locator hitting as well as it did right out of the gate not only says a lot about the team and the technology - but I think it says a lot about good luck as well.
