When Flight MH370 shut off its transponder, it disappeared from Malaysian radar and was declared missing. Before the disappearance could be called a crash, the possible locations of the plane had to be computed. An Inmarsat comms satellite first picked up an automated signal from the plane’s satcom link at 02:11, receiving 8 hourly ‘pings’ in total, before the last at 08:11. From the time it took the pings to reach the orbiting satellite and the angle of their elevation, Inmarast calculated there were two arcs the plane could have taken. The northerly arc stretched to Central Asia, the southerly arc swept into the Indian Ocean. Inmarsat refined its calculations and compared its various model flightpaths to real-world trajectories, so ruling out the northerly arc and narrowing the plane’s last known location to just 3% of the southerly arc. These findings were accepted by the Malaysian government, who at 22:00 on March 24th 2014 declared that the plane had crashed into the Indian Ocean, with all lives lost. MH370 RIP: http://www.malaysiaairlines.com/content/dam/mas/master/en/pdf/Malaysia%20Airlines%20Flight%20MH%20370%20Passenger%20Manifest.pdf