Originally Posted by
Tiger65
What was a roll registered by two separate FDRs?
Both FDRs register the same digital data. Analog data is converted to 8-bit digital by an ADC. 8 bit is quite coarse resolution, so each parameter has limits. Judging by abrupt evenly horizontal line at the end of the roll angle data on page 175 of
English version of MAK report, FDRs record roll over the limit as the limit. But that's too complicated for conspiracy theorists. If you indeed are interested in anything else than ominously shouting "Russians did SOMETHING", read RTE (technical manual, not flight manual) what are limits of recorded roll angle. Yak-42 aircraft has similar FDR MSRP-64M-2, on page 606 of
chapter 142 of its RTE the limit of recorded roll angle is specified: +-60 degrees.