Quote from me:
"The DFDR trace shows the a/c consistently lower, eventually below 30 ft QFE."
Quote from CONF_iture:
"I don't see any QFE altimeter reading in the DFDR traces, do you ?"
Sorry, Confit, that was sloppy of me. I should have acknowledged that the "trace" I was looking at is in the report that Airbus themselves did in 1995, not the BEA report.
However, Annexe VII of the BEA Rapport Finale, "Tome 1", represents one of the lists of second-by-second flight parameters decoded from the DFDR. Inconveniently, on my PDF copy the print is reminiscent of the blurred, bottom carbon-copy of a document created on a cheap portable typewriter. (How DID we ever manage in those days?)
Column 2 is a second-by-second timeline.
Columns 3 - 5 are barometric readings, which I'll now try to explain in fundamental terms for our non-aviator readers.
Column 3 seems to be the flight level, sampled every 4 secs, and rounded down. (So "+018" means FL 018.)
Column 4 is either the QNE (i.e., the pressure altitude, based on the standard sea-level pressure of 1013.2 hPa) or the altitude above sea-level, based on the current QNH of 1012. (More likely the QNE.) I am ignoring that parameter.
Column 5 is almost certainly the actual reading on the captain's altimeter, the sub-scale of which would have been set to the QFE of 984 hPa.
(For the uninitiated, that would theoretically read between zero and -15 ft for an a/c parked on the airfield with a perfect altimeter. The lower figure of -15 ft would apply if the precise pressure at the airfield had been 984.5 hPA, which ATC would have broadcast as 984 hPa.) So it is the best reading of height above the airfield obtainable by barometric means. (See my previous post.)
At time 332.0 secs, the value (as far as I can see) is 0030.
At time 333.0 secs, the value (as far as I can see) is 0024 or 0026.
At time 334.0 secs, the value (as far as I can see) is 0024 or 0026.
At time 335.0 secs, the value (as far as I can see) is 0?48 or 0248.
(The latter may be the defined point of "impact".)
At time 336.0 secs, the value (as far as I can see) is 0000, and remains so until the end of the recording at 339.0 secs.