RIASS acts as a “safety net” in the system of tower-led air traffic control at Amsterdam Schiphol Airport, warning of potential conflicts between aircraft or with vehicles on the runways and at their entrances and exits.
RIASS generates two kinds of alert: alarms and warnings. An alarm indicates that there is an imminent danger of collision and the air traffic controller must respond to the situation immediately. As far as possible, however, an alarm is preceded by a warning. This gives the controller the opportunity to determine whether the risk of a collision might arise. The system is only able to generate alerts in respect of aircraft and vehicles fitted with a working transponder.
