Originally Posted by
wheelsright
Apparently they have the MCP settings from the Mode S- extended squitter (ES). That's how they know it was intentional.
Is there official confirmation of that? Selected altitude/rate parameters would establish the intention of altitude change.
It would have been very strange if ATC hadn't been recording Selected Altitude, given that there would have been several Mode S radars within range, interrogating the flight for that and other parameters (ironically, to detect a level bust).
See here:
We have analysed the raw data from the transponder of #4U9525 and found some more dat
for the couple of seconds during which SEL ALT was changed from 38,000ft to 100ft.