Ultra high frequency for air traffic control

The ultra-high frequency (UHF) radio infrastructure (225 MHz - 400 MHz) is used by most air navigation service providers (ANSPs) as a fundamental alternative to ensure ATC communications with non-8.33 kHz equipped State aircraft operating GAT/IFR and, in some cases to support OAT flights.

These ATC-related UHF services can be provided by civil and military ANSPs. Depending on the State’s local arrangements, military ANSPs normally provide UHF support for OAT flights whilst civil ANSPs can offer this service for State aircraft operating as GAT/IFR and OAT.

The provision of UHF or VHF 25 kHz to communicate with non-8.33 kHz equipped State aircraft is a regulatory obligation. As transcribed in section 2.3, Article 9 (12) of the SES Regulation (EU) No 1079/2012 states:

Air traffic service providers shall ensure that State aircraft not equipped with radios having the 8,33 kHz channel spacing capability can be accommodated, provided that they can be safely handled within the capacity limits of the air traffic management system on UHF or 25 kHz frequency assignments.

Member States are also required to publish the procedures to handle non-equipped State aircraft in their national aeronautical information publications (AIP).

To establish the appropriate level of UHF provision by civil and military ANSPs for the safe handling of non-equipped 8.33 kHz State aircraft, a number of requirements need to be fulfilled such as:

• Availability and geographic coverage of the UHF service
• Improved civil-military frequency management coordination when allocating UHF frequencies (in particular when civil ANSPs need to obtain UHF assignments in a band managed by national military frequency managers and/or NATO)
• Establishment of operating procedures related with the use of UHF to handle flights commonly agreed between civil ANSPs and military operators
• Availability of recognised technical standards (as UHF is a military specific requirement)
• Optimal/full system integration and lack of cross-coupling with VHF channels
• Local safety cases

Most of these requirements have been subject of specific guidance contained in the document: EUROCONTROL Guidelines on the Use of UHF for ATC, GUID-138-2009, Edition 1.0, 2 June 2010.

The SES regulatory developments acknowledged that 8.33 kHz expansion entail a number of support measures, including UHF provision, while paying due regard to the technical, operational and economic aspects. We worked on the harmonisation of UHF used for air traffic control in close cooperation with the NATO Spectrum Management Branch (SMB).

The users of this guidance material are advised that it neither replaces any local regulations nor the safety assessments that have to be undertaken locally before implementing UHF installations or procedures.