The runway-numbers drop the LAST, not the 1st, numeral,

Yes, thank you, i meant what you wrote, but said the opposite. A not infrequent error, sadly

I had forgotten about the battery backup. I’m not sure what the law is in S. Korea and surrounding countries. If the accident plane only flew in Asia and none of the destination countries required that equipment they may not have had backup batteries for the CVR/FDR. Dunno about any of that tho