So Sun, it does beg the question, why have they spent so long doing it and been throwing buoys out of the back pf their aircraft then?
Because they're doing their best with what they have.
I'm not arguing against them being used, I'm saying they have a very difficult task in this instance because it's not what MPA were designed of bought for. They do not have equipment designed to find sunken civilian aircraft (or military ones for that matter).
As always, the boys and girls will do what they can with what they have, and as a result of skill, and not a little luck, they might find something.
Sun.