It now seems as if the data from both the CVR and FDR for the Jeju B737 are lost, or to be more accurate, they were not operative in the last 4 critical minutes of the flight.
So there are still many unknowns as to what happened.
This clip from YouTube explains the situation well...
https://www.youtube.com/watch?v=0CgO01n1px0It's a very strange accident, apparently an independent power source for the CVR and FDR was an optional extra which had to be ordered by the original purchase airline (not requested) which was Ryanair in 2009. It seems crazy to me that a backup power supply for these is not mandatory.
As for the gear up approach,nothing new has come out yet,an APU was fitted to the aircraft, but from what I have read these can take a few minutes to spool up to usable power.
I doubt the answers will be found for quite some time without the CVR/FDR info at the critical stage.There has been unconfirmed reports that the crew may have shut down one of the engines, possibly the wrong one after the birdstrike.
I'm not aware of any of the Comms with ATC being made public as yet.