That's right Slide.
My point was that AF447 transmitted a "routine" position update on a fixed schedule, then a few seconds later started transmitting ECAM alert stuff and aircraft system stuff for the next four and a half minutes. The data was invaluable when the FDR and CVR was available to correlate.
This is not what happened with 370, and it's time interval was 30 minutes, apparently. It also did not start up when "something" happened, if there was a severe problem versus conspiracy theory stuff. I wonder if the carriers preserved ACAR data from the 9/11 planes?
Sheesh, if the flight goes smoothly than there ain't much to look at on the tapes/disks. If there's minor mechanical problems, you can do required trouble shooting and repairs. If the end result is a crash, then the data is invaluable for preventing a future episode.
BTW, I flew the first USAF fighter with a solid state recorder to keep you from lying to the accident board. Sucker was in our seat, and we didn't know it was there until after a crash or two. Was not nearly as comprehensive as the FDR on the big jets, but it sure helped re-construct what happened and keep it from happening again. Also had a big time FDR in one outta six of the first 40 - 50 jets. If it was recovered, we had even more data. Also had a video recording of our HUD, which had some gruesome footage on a few crashes.