[gchadwick]

The article says it disappears from radar. When tracking aeroplanes there are two kinds of radar primary and secondary. Primary is actual radar, secondary isn't really radar at all but instead radio transmission of telemetry such as position, altitude, speed etc. This is equivalent to AIS, the system used to track boats that produced your image.

So we were tracking the plane but then the plane stopped transmitting tracking info for some reason (no idea if they even had it on primary radar). Someone could have turned it off or the plane could have crashed.

[brador]

There is no need for a pilot to be able to disable tracking on a commercial plane.

They should position the tracking hardware outside the plane making it relatively tamper-proof mid flight.

[tonylemesmer]

Unless its on fire? Isn't that always the reason for having all the kill switches on aircraft?