so there is little perceived benefit in imposing a much more expensive equipment upgrade on the global fleet.
Has it ever been costed?
Has the idea ever been discussed?
If AF447 could be sending back live data about its pitot tubes and air con packs, and the QA 380 could be doing similar things with its engine parameters, surely it is not beyond the wit of man to start fitting FDR/CVR transmitters to all a/c being manufactured from 2018.
Remember the debate about cargo fire detectors and extinguishers after the Valuejet cargo fire? The FAA did a risk/cost analysis about retro-fit of all similar type a/c. It was considered too expensive. The category of cargo hold was designed to survive a fire as it burnt itself out. There had not been a precedent to Valuejet, and it was deemed that had root cause in human error. Notice, now, that all B737 NG and AB's, with the same category of cargo holds, now have fire detection AND extinguishers. They were designed in and cost absorbed. When was the last time they were used? How many times in past 20 years? Yet they are there. How many times would FDR/CVR dreaming have been invaluable in the same time frame? And in the future which is more likely to be needed the most; cargo fire or FDR/CVR data?