If these calls went all the way to the phone, then there is a record to trace which cell phone tower the phones were using, which would pinpoint the phones pretty close. Even if these call didn't make it, but the phones were active, and the plane is landed somewhere, there almost certainly would be a tower nearby that would pick up a ping. I think someone knows where the plane is.
If this plane crashed into the ocean wouldn’t the water damage the cell phone. I know with mine I had several incidents where water got into my cell phone (don’t ask lol) and it would stop working. The phone buttons do not operate and it acts up like it is possessed.