IFF/SSR Interrogators are defined in CAP 761 (formerly CAA Doc 714) as all equipment capable of transmitting in the 1030 MHz frequency band. This includes Ground-Based, Airborne and Maritime Secondary Surveillance Radar (SSR), Airborne Collision Avoidance Systems (ACAS), some Collision Warning Systems (CWS) and Active Multilateration Systems (MLAT). The application and approval procedures detailed within CAP 761 apply to all operators of IFF/SSR systems: civil or military, operational or T&D, domestic or visiting.
The requirements for approval of Mode S SSR Interrogators are the same as that for any SSR interrogator and are described above.
Applications for approval to operate Mode S radar will normally require an additional application for a Mode S Interrogator Code (IC). Details of the IC application process can be found in the Mode S Interrogator Code Allocation Process document produced by Eurocontrol. Applicants are advised that there is a six-month allocation cycle, based on the AIRAC cycle, associated with IC applications and should therefore submit applications to the NISC Secretariat in a timely manner.
Details of current and future UK Mode S policy and regulations can be found on the CAA Mode S webpage. In addition the Eurocontrol website may provide some guidance on Mode S developments throughout Europe.
The approval guidelines detailed in CAP 761 also apply to Airborne Collision Avoidance Systems (ACAS), often referred to as Traffic and Collision Avoidance Systems (TCAS). ICAO Annex 10 compliant ACAS II systems have a generic approval from the NISC. However, ACAS I systems require approval on a case by case/individual basis. Individuals/organisations intending to equip their aircraft with ACAS I equipment should read AIC 37/2006 (Yellow 199) 30 Mar 06, in addition to CAP 761 prior to buying and installing any system.
Forms for approval to operate are available at Forms and Documents.
