DravidDavid:
It could have been autopilot bugging out, taking the plane to a stupid height, stalling and correcting itself again. Who knows.
Well nobody "knows", but the explanation given above, supported by fact that the transponder wasn't working, and that it was a long way from radar sites, suggest that altitude estimates from primary radar would not be very accurate at all (could be many thousands of feet out). So it's not sensible to speculate why something like that was done, when there's really no evidence that it was done at all.


