[hamboy]

Egyptian el-Sisi is no nonsense he'll get to the bottom of it no matter what it takes, he's against isis/isl, jihadists, brotherhoods. AF447’s black box wasn't found until 2 years later, what they concluded initially as cause of crash based upon ACARS, the FDR only concurred whatever they yielded in the ACARS. So ACARS is good enough. Even if ELT's battery run out, the SONAR can pinpoint any metalic object in the ocean floor, having so called better technology to find the FDR is irrelevant.

[virgil]

They spend a lot of time and resources collecting debris and looking for black boxes to find the root cause. Every crash is different, and SONAR has limitations. I don’t know what kind of signal is emitted by the boxes. I thought it was a high frequency ping. Maybe a different kind of signal that penetrates water and earth, and can provide directional homing.