As layman I keep asking myself why the black boxes data ain't being sent to a central computer on Earth via satellite
Apart from how a Sat signal can be disrupted by a storm, if the antenna is at the wrong angle, You have to send from one place on the planet to another and it has to be bounced over several sats/ground stations........ Every down/uplink is a weak spot.
Sorry, but I think this is something else tht has been explained before. Sat signals can be disrupted easily by a storm (would have worked well IF AF447 flew into one, wouldn't it), as I am sure we have all seen live sport broadcasts "break up", we've seen Sat TV break up because of local weather and, if you have a GPS, you'll have seen that lose the signal too depending on local weather. All you need is a good storm in the way of one up/downlink station and you don't get a thing transferred from the Pacific to Paris (or, in this case, the Atlantic to Paris)