The Ferret King posted:

They show up quite well on primary radar systems (thanks for reminding me I need to do a breakdown of those ASAP.)

I wasn't clear from the news stories whether this particular aircraft was in radar contact with an ATC organization during the time of the crash though. The reports I read made it sound like it was making scheduled check-ins via radio, which is more in line with non-radar forms of control. I know they've found radar plots of the aircraft from places like flightradar24.com and other entities, but I wasn't sure that any of those sources were actually responsible for control of that aircraft.

Either way, even with good radar coverage up high, it's likely that coverage disappears entirely at a certain altitude and below, especially over water.

I've tried to keep up with the reports periodically, could you link any stories you find regarding the radar data used for that flight so far?