AF447 had a similar scenario, but after the public gradually lost interest, the search was scaled down and then ended. It was only a proper review of the evidence, and a proper and thorough search of the only area it could have been, that solved the mystery.
With AF447 it was actually different, first of all floating debris was identified relatively soon - within a few days. Then French searched underwater for a year and could not find anything. A US oceanography research firm was then hired to perform extensive calculations which ultimately led to finding the wreck.