CVR recording time
It amazes me that the CVR overwrites its recording after only two hours. That may have been a resonable limit when such recorders were first introduced, since the motivation was to capture the conversation in the prelude to some catastrope. However in some recent events, such as the Qantas depressurisation and possibly the Ryanair incident, the recorder has not stopped until more than two hours later, so erasing potentially valuable information. Pulling the relevant circuit breaker in flight might preserve one lot of information, but if the landing should go wrong something even more valuable could be lost.
Since there are now small lightweight devices (think iPod) that can hold many hours of user-recorded music, what is to stop the current generation of CVRs being replaced with solid state devices capable of capturing everything said from ground power on to beyond final shut down on a maximum-range flight? If magnetic tape has better survivability than solid state memory, then a solid-state secondary recorder could still be a useful backup - tape to record the run-up to a catastrophic destruction, solid state to record a less severe event further back from the end of the flight.
Solid state recorders could be small and light enough for several to be installed in different places, to record the same things, increasing the chance that at least one would survive an accident in a usable condition.