TDR-94-94D Mode S Transponder

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 that comply with RTCA document DO-185A, also identified as DO-185 Change 7.0.



Phone 1: 319-295-4085

Technical Support

Phone 1: 319-295-5000

Features & Benefits

  • Enhances crew situational awareness: Real-time visual display of surrounding traffic situation and potential collision threats provides flight crew with improved safety.
  • 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 7.0 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.
  • Optional “ADS-B out” capability: Provides non-radar area surveillance.
  • 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.
  • Growth capable: Incorporates features allowing future system growth such as ATN and NextGen.