Originally Posted by HN39
RE 1: In those days the BEA didn't have facilities to read DFDR tapes and decode the data. The tape was read at the CEV (Centre d'essais en vol), the french military flight test centre, which also does civil certification test flying and houses the french national test pilot school. The print looks to me like it was produced on a IBM typewriter or daisy-wheel printer and published in the report as it was received from the CEV.
Coming from you, I am usually expecting more solid argumentation ...
RE 2: The DFDR GMT parameter probably records only hours and minutes (remember the timestamp of the AF447 ACARS messages?). The seconds have to be determined by counting the frames, and fractions of a second from the parameter position within the frame word sequence. Who sets the GMT clock in the airplane? The wording of the note in the Airbus memo suggests that TGEN is not a recorded parameter but a frame count added in the CEV printout of DFDR data.
the DFDR has a very accurate elapsed time-base and however erroneous the airplane clock could be set, what matters is the full DFDR time for the duration of the flight and the correlation with the CVR that can be established for the
total duration of that flight.