But it didn't jammed the signals coming from the engines.
Rolls royce have this maintenance thing built into their
engines, that send out running data by the hour that gets logged
into their database.
Thats how they know it flew another 5 hours, because it was
still pinging.
What it does not send out is the location, but it can tell the
altitude. And from that, they could tell at one point that plane
flew at 45000ft, 777-200 operational ceiling is 43100ft, and went
down to 23000ft, then up again.
