Perhaps I was not clear enough. There is no need to transmit all this data all the time. The idea is not to replace black box, but to regularly transmit only very small subset of its data, so that the plane can at least be found. Basically, it should transmit only what is necessary, and only when it become necessary. Intelligent device must periodically send just GPS position and basic flight information in small and highly compressed single packet, using cheap, low bandwidth link. Having all relevant data at its input, it would always be aware of severity of any fault status or warning, and it would only then transmit more data, if necessary opening more expensive higher capacity link. In most dangerous situations, it would open emergency, reserved, highest capacity satellite link, and in a very short time upload every single bit of highly compressed data at its disposal. That could be much more than any current black box could hold. On average it would require, for example, just 1 KB of data by lowest capacity link every 10 minutes, so extra price would be very small, and we would still immediately have all the content of black boxes in all detectable emergencies. Traditional black boxes would still be there in case of communication problems.