8.33 kHz voice channel spacing below FL195

Radio frequencies are a scarce resource which needs to be optimised in order to support the efficiency of Network operations and the achievement of the Network performance targets. In view of the current and expected demand for radio communication frequencies, especially in core European airspace, a successful implementation of 8.33 kHz voice channel spacing (VCS) below FL195 is required in order to meet the capacity demand.

Air-ground communications using VHF 8.33 kHz channel spacing were introduced in European airspace to alleviate VHF congestion. In 1999, some 30 States within the ICAO EUR region enforced mandatory carriage of 8.33 kHz radios above FL245.

Following this decision, the European Commission (EC) undertook to regulate the implementation of VHF 8.33kHz voice channel spacing in European airspace below FL245 down to FL195 (Air Ground Voice Channel Spacing (AGVCS) Implementing Rule (IR) - EC Regulation No 1265/2007) and then further below FL195. The final regulation has been published in the Official Journal (EU No 1079/2012 or L320/14 of 16 November 2012).


VCS Regulation milestones


VCS Regulation milestones


For further guidance and supportin documentation for the extension of 8.33VCS implementation below FL195, please see "Related links" section.


VCS Regulation

The VCS Regulation extends to the lower airspace (below FL195) the requirements, covered in Regulation (EC) No 1265/2007, for the coordinated introduction of air-ground based voice communications based on 8.33 kHz channel spacing.The Regulation applies to all radios operating in the VHF band, to flight data processing systems serving general air traffic and to all flights operating as GAT (General Air Traffic / civil) within the airspace of the ICAO EUR region. It consists of interoperability, performance and deployment obligations, with relevant application dates, for manufacturers of radios, for ANSPs, for operators and other users of radios, for Member States and for the Network Manager. It includes operational procedures based on ICAO provisions, as well as specific arrangements for State aircraft, and provisions for exemptions.

The full content of Commission Implementing Regulation (EU) No 1079/2012 can be consulted in the "Related links" section of this page.

Since the adoption of Commission Implementing Regulation (EU) No 657/2013 of 10 July 2013 amending Regulation (EU) No 1079/2012, several stakeholders (radio manufacturers, operators or National Supervisory Authorities) have requested clarifications of specific provisions of the Regulation. Answers to these requests for clarification have been compiled in a Frequently Asked Questions document (see "Related links" section).

Specific considerations derived from the Regulation, applicable to State aircraft, can be found in "VHF 8.33 kHz - State Aircraft" (see "Related links" section).

8.33 Implementation Support Group

In order to support its stakeholders in the process of implementing the Regulation, the Network Manager has set up a dedicated 8.33 Implementation Support Group (8.33ISG). For further details regarding the activity and deliverables of the 8.33ISG, please access the Team’s OneSky workspace (registration is required - see "contact" box on the right).




The following standards are applicable to 8.33kHz radio equipment

ETSI EN 300 676-1 V1.4.1 (2007-04 - pdf)

Electromagnetic compatibility and Radio spectrum Matters (ERM); Ground-based VHF hand-held, mobile and fixed radio transmitters, receivers and transceivers for the VHF aeronautical mobile service using amplitude modulation; Part 1: Technical characteristics and methods of measurement.
ETSI EN 300 676-2 V1.4.1 (2010-04 - pdf)
Ground-based VHF hand-held, mobile and fixed radio transmitters, receivers and transceivers for the VHF aeronautical mobile service using amplitude modulation; Part 2: Harmonized EN covering essential requirements of article 3.2 of the R&TTE Directive.
EUROCAE ED 23C  (June 2009 - link) Minimum Operational Performance Specification for Airborne VHF Receiver-Transmitters operating in the frequency range 117.975 – 137.000 MHZ.

Frequency/channel tables

Normally in aviation (e.g. in radio telephony), the frequency in use is identified by the actual frequency. For the use of 8.33 kHz channel spaced communications, the frequency identification is replaced by a channel which uses a number (similar to the identification of a frequency) mapped to the actual frequency in use. The channel/frequency identification to be used for identifying frequencies with a channel spacing of 8.33 kHz is as shown in the “Related links” section.