Spectrum & Frequency Management

Information Relating to Spectrum & Frequency Management

Surveillance (Including SSR) Policy, Regulation, Legislation & Allocation. National IFF/SSR Committee & S&SWG Secretariat. Chairman of CAA Mode S Working Group. Spectrum & frequency management for the aeronautical frequency bands. Comms & Navaids. UK aviation representative FM study group. ICAO ACP International Telecommunications Union (ITU), IFF/SSR Frequency Approvals. Spectrum & frequency management, planning frequency bands for civil & military. Liaison with HM Government, Department of Trade & Industry, DfT, MOD & special organisations on IFF/SSR, frequency management, regulation & protection.

As part of Government plans to release a proportion of public sector spectrum by 2020 for commercial use, such as for mobile broadband, the UK Civil Aviation Authority (CAA) has been tasked with assessing the possibility of safely reducing the aviation industry’s reliance on the bandwidth reserved for air traffic control radar. A major research programme will look at the feasibility of releasing 100MHz of the 2.7GHz–2.9GHz band currently being used for civil and military primary surveillance radars.

Read more about our work on the Spectrum Release Programme

Mode S

SSR Codes

The CAA provides the focal point for the implementation of Mode S SSR in the UK and is responsible for the management of the UK SSR code allocation plan.

Transponder Carriage Requirements

Transponder Carriage Requirements are published in UK AIP - GEN 1.5 - Aircraft Intruments, Equipment and Flight Documents. 

General Mode S enquiries can be submitted to mode.s@caa.co.uk

ICAO 24 bit Aircraft Addresses

The provision of Air Traffic Services (ATS) in an SSR Mode S environment relies on a unique ICAO 24-bit Aircraft Address (24-bit AA) for selective interrogation of individual aircraft.

More information about ICAO 24 bit aircraft addresses

IFF / SSR Forms and documents

CAP 761 sets out the application procedures and the basic planning principles that will be applied before approval of any new interrogator installation or changes to an existing approved interrogator installation.

DAP 1910 - Application to Operate a Secondary Surveillance Interrogator in the United Kingdom - Ground Based Platform

DAP 1911 - Application to Operate a Secondary Surveillance Interrogator in the United Kingdom - Maritime or Airborne Platform

DAP 1912 - Application to Operate ACAS (TCAS) within the United Kingdom - Note: Certain equipments are now covered by a generic approval and an application may not be necessary; even if an approval was required previously. Check CAP 761 before submitting a new/renewal application.

DAP 1913 - IFF/SSR Interference Reporting Form