The takeoff phase-of-flight, as determined by the system, must be valid in order for the system to issue Takeoff Alerts. Takeoff Alerts will be issued when the thrust levers (throttle) are advanced to near the TO position. Nominally, the aircraft will be in the SurfaceWatch 'Takeoff Phase-of-Flight' when the aircraft starts its takeoff maneuver (e.g., the throttles are pushed forward).