The CNS/ATM Transponder

The XS-950 Air Transport Data Link (ATDL) Mode S transponder is a full-feature system combining flawless implementation of all currently defined Mode S functions with unparalleled capability for future growth.

Over 4,000 XS-950 Mode S transponders have been delivered to more than 100 operators worldwide since the product debuted in 1996. Most Air Transport OEMs offer the XS-950, including Airbus, Boeing, Antonov, Ilyushin, and Tupolev. Airline industry leaders such as British Airways, Crossair, Federal Express, Iberia, KLM, Northwest Airlines, Qantas, Saudia, SWISS Airlines, and UPS have selected XS-950 as their transponder system of choice.

Our Mode S transponder is the industry’s only ICAO Level IV transponder, capable of both uplink and downlink extended length messaging (COMM-C/D). The XS-950 meets or exceeds the latest requirements of ICAO Standards and Recommended Practices (SARPs) Annex 10 and RTCA DO-181C Minimum Operational Performance Standards (MOPS) for Mode S equipment and ARINC 718A Mode S characteristics.

The XS-950 has all of the required functionality for ICAO ACAS II mandate compliance, European Elementary and Enhanced Mode S Surveillance Downlink of Aircraft Parameters (DAPs), and ADS-B 1090ES extended squitter, as currently defined in the Aeronautical Information Circulars (AICs) and ICAO SARPS.

The XS-950 Mode S transponder has been designed for reliable performance and ease of maintenance. Highly Accelerated Life Testing (HALT) was performed on all engineering models of the XS-950. Each production XS-950 unit is subjected to Highly Accelerated Stress Screening (HASS) before being shipped to customers to ensure the highest product quality and to prevent failures from ever reaching the end user.


The ACSS Identification Friend or Foe (IFF) Transponder (XS-950SI) was selected and certified by the U.S. Navy as the transponder of choice for C-130, VP-3, C-12, and C-2 aircraft. Boeing selected the XS-950SI for the 767 Global Tanker Transport for domestic and international tankers, and the U.S. Army selected the XS-950SI for the UC-35 Citation Ultra. Maximizing the use of commercial-off-the-shelf technology, the XS-950SI enables coordinated and simultaneous Mode S and IFF capability that is necessary for TCAS II operations. The FAA certified XS-950SI is a full-featured transponder implementing all currently defined Mode S and IFF functions, including DO181B Elementary & Enhanced Surveillance, GPS position, velocity, and Flight ID extended squitter.

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