Rockwell Collins’ TDR-94D Transponder is an all solid-state, crystal-controlled receiver/transmitter specifically designed for TCAS-II-equipped business aircraft and regional airliners with 28 V DC electrical systems and limited space. It is the airborne portion of the Air Traffic Control Radar Beacon System.
Its active transponder replies to ground-based Secondary Surveillance Radar interrogations to provide air traffic controllers with aircraft position identification, altitude and enhanced surveillance data. The TDR-94D is compatible with TCAS II receiver/transmitters.
The latest models of the TDR-94/94D are fully compliant with the latest DO-260B ADS-B Out standard for upcoming mandates. Service bulletin upgrades are available for select earlier models of the TDR-94/94D to bring ADS-B Out capability. For US-registered aircraft without Flight ID capability, our latest -502 variant will generate a fixed flight ID based on the Mode S code to meet ADS-B Out requirements, avoiding the need to update controllers or other systems. To learn more about ADS-B Out and upgrades for your aircraft visit
rockwellcollins.com/ads-b.