MH370 – Caption – A New Plausible Piloted Trajectory [pdf]

recoverable in one piece, probably, but will the data still be usable? that's a very different question.

Most likely. Flight data recorders are designed to withstand over 3000 g of acceleration.

The problem with finding them, however, is they have a beacon that pings every second after coming in to contact with water, but this only lasts 90 days, and can only be detected at under 3-5km depths.

Some of the ocean areas where the plane was suspected to have crashed are much deeper.

After seeing what the ocean did to Titanic over the years, I doubt. Who know what kind of bacteria/chemicals are feasting on it.