Mode S Transponders - A New Avionics Product

A new Air Traffic Control Radar Beacon System (ATCRBS) Transponder is required in all new aircraft manufactured after January 1, 1992. These transponders, designated Mode Select Beacon Systems (Mode S), will provide improved accuracies in the surveillance of aircraft position and more interference-free identity and altitude reports to Air Traffic Control (ATC). Mode S transponders will also play an important role in the Traffic Alert and Collision Avoidance System (TCAS), providing the datalink between two TCAS equipped aircraft.