Appendix A - Background information on Mode A/C surveillance systems

• ED Decision 2022/008/R found in: GM Remote Aerodrome Air Traffic Services (ED 2019/004/R) Issue 2 (Jul 2020)

Appendix A – Background information on Mode A/C surveillance systems ED Decision 2022/008/R (a) General This Appendix provides additional references, background information, and guidance for maintenance testing, as appropriate to Mode A/C surveillance installations. (b) Related references (1) EASA ETSO-C74d**,** Minimum Performance Standards for Airborne ATC Transponder Equipment. (2) ICAO (i) ICAO Annex 10, Volume IV, Aeronautical Communications (Surveillance Radar and Collision Avoidance Systems), Amdt 85; (ii) ICAO Document 8168-OPS/611 Volume I, Procedures for Air Navigation Services, Aircraft Operations; (iii) ICAO Document 4444-ATM/501, Procedures for Air Navigation Service, Air Traffic Management; and (iv) ICAO EUR Regional Air Navigation Plan, Part IV, CNS Supplement SSR Code Allocation List for the EUR region, current edition. (3) EUROCAE (i) ED-43, Minimum Operational Performance Requirements for SSR Transponder and Alticoder; and (ii) ED-26, Minimum Performance Specification for Airborne Altitude Measurement and Coding Systems. (iii) EUROCAE document 1/WG9/71 June 1972 MPS for airborne secondary surveillance radar transponder apparatus - Including Amendment N°1 (measurement procedures)-April 1974 & Amendment N°2-January 2000 (4) RTCA (i) DO-144A Minimum Operational Performance Standards (MOPS) (c) Background information Airborne surveillance system The following diagram presents the Mode A and C transponder and its main functional interfaces. <table cellpadding="0" cellspacing="0" width="100%"><tr><td><div><p>Mode A and C Transponder</p></div></td></tr></table> <table cellpadding="0" cellspacing="0" width="100%"><tr><td><div><p>Top antenna</p></div></td></tr></table> <table cellpadding="0" cellspacing="0" width="100%"><tr><td><div><p>Bottom antenna</p></div></td></tr></table> <table cellpadding="0" cellspacing="0" width="100%"><tr><td><div><p>Altitude source</p></div></td></tr></table> <table cellpadding="0" cellspacing="0" width="100%"><tr><td><div><p>IDENT (SPI) interface</p></div></td></tr></table> <table cellpadding="0" cellspacing="0" width="100%"><tr><td><div><p>Mode A code interface</p></div></td></tr></table> Figure 2: Mode A/C transponder interfaces [Issue: CS-ACNS/4]