Collins Aerospace’s 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.

Learn more about ADS-B Out and upgrades for your aircraft. 

  • Compliant with latest ADS-B Out standards (-501/-502 only)
  • ADS-B features: Meets DO-260B ADS-B Out requirements for upcoming/emerging mandates; Mode S generated Flight ID capability for United States registered aircraft (-502 only); capable of pairing with Collins Aerospace or other compatible GPS receivers
  • Transponder features: TCAS II compliant; datalink capable for TCAS II crosslink and ATC data communications; ICAO Level 3s capable; provides Mode S elementary and enhanced surveillance.
  • TCAS II features: Change 7.1 compatible; replies to ATC radar on Modes A, C and S with altitude.
  • Capable aircraft IO architecture: Accepts ARINC 429 or commercial standard data bus control and altitude information; flexible air data interfaces for compatibility with all aircraft.
  • Maintainability features: Diagnostics for easy fault isolation and shop maintenance.
  • Flight deck control: Operates via the CTL-92E transponder control, radio tuning unit or FMS.
  • Efficient packaging: Housed in a specially designed package for efficient heat transfer and resistance to high-intensity radiated fields.