It crashed Catastrophe at around 9.15 pm CET while travelling Self_motion on the A9 motorway near Sierre , in the southern canton of Valais .

The aircraft , a Turkish Airlines Boeing 737-800 , crashed Catastrophe into a field approximately north of the Polderbaan runway , ( 18R ) , prior to crossing Motion_directional the A9 motorway inbound , at 09:26 UTC ( 10:26 CET ) , having flown Motion from Istanbul , Turkey .