Originally Posted by
OA32
For those of you wondering about the radar, SSR only tracks can appear to weave regardless of a/c type and aren't as reliable as primary returns, this is the reason that 5 mile spacing is required for SSR only radar separation as opposed to 3 miles for primary radar. As such it cannot be relied upon as an indication of the plane being hand flown as opposed to autopiloted.
OA32,
The bulk of the radar track has these very small deviations (it looks like about 0.05 miles each way - which is entirely consistent with your comment). However, in the final 30-40 seconds there is an initial large heading to the South (it looks like a course change of c.30 degrees and maintained for about 20 seconds.)
It seems a reasonable assumption that the autopilot was turned off at this point (or was operating in an unanticipated way). From watching people fly G1000 aircraft, it would be plausible the descent was mis programmed and the pilot disengaged the autopilot when he realised this.