Runway Updating CFM 9.79

(a) RNAV requires that the FMS position be updated just prior to takeoff. As long as the GPS is operational, this position updating takes place automatically. In the event the GPS is inoperative, the pilot can accomplish this by pushing the TOGA button located on the thrust levers. This updates the aircraft's position to the coor-dinates of the departure runway threshold. When the position update is complete, the annunciation “COMPLETED” shows above the RWY UPDATE on the CDU. Runway updating should occur within 1,000 feet of the departure end of the run-way to be used.