acars stops transmitting information about the plane's operating condition. and that was before the last radio transmission, all right, good night, indicating everything was normal. 1:21 a.m., the transponder which identifies the aircraft on radar, stops transmitting. was someone trying to hide the plane? we also now know blips then seen on malaysian military radar were in fact flight 370 headed west and authorities say there is every indication someone was in control. >> until the point at which it left military primary radar coverage, this movements are consistent with deliberate action by someone on the plane. >> reporter: still unclear whether it was a pilot or hijacker. cnn has confirmed the plane made