The missing Malaysia Airlines airliner first deviated from its set flight path following an entry into its flight computer, according to a new report.

The New York Times, citing “senior American officials,” reports Flight MH370′s first unexpected turn to the west was made “through a computer system” in the aircraft’s cockpit. That revelation is significant because changing the aircraft’s route via the flight computer requires a more intimate understanding of the Boeing 777′s flight systems than manually manipulating the control yoke to change heading.

Commercial jets and other large aircraft typically travel the skies via a system of waypoints, each identified by a five-character code. Those waypoints are manually entered into an aircraft’s flight computer so the airplane’s autopilot system can fly the desired route. Pilots can insert new waypoints into an aircraft’s flight computer to change the aircraft’s course mid-flight if asked to do so by an air traffic controller or for other reasons.