• To overcome aviation radio frequency congestion across Europe, more channels are needed. By moving to 8.33 kHz channel spacing, three times the number of channels can be created within the VHF band.

  • 8.33 kHz VCS will utilise a 'frequency like channel number' when spoken and dialled on a radio unit.

    If a channel is operating in 833 it will have a 6 digit channel ending: 05, 10, 15, 30, 35, 40, 55, 60, 65, 80, 85 or 90

    Initially most channels will convert to allocations in bold (05, 30, 55 or 80) that are the closest corresponding channel to their existing assignment. Further details on the channel numbering system are listed in CAP1573

    Radio capability 

    Generally, if a radio can tune to 8.33 channels then it is suitable. Some radios may have to have an '833 mode' enabled through the menu system. Please check the operator's manual for further information and if in doubt check with the manufacturer.

    Handheld radios

    Handhelds can be used within the terms of the LA301075 approval and may be a suitable means to equip and can also be useful as a backup.

    25 kHz radios

    If a frequency assignment has converted, and is operating on a channel that is identified as 8.33, an 8.33 capable radio must be used.  Any attempt to communicate on a 8.33 channel using 25 kHz equipment could cause interference with neighbouring assignemnts and risks potential enforcement action from Ofcom.

    25kHz ground stations

    Radios are backwards compatible. So an upgraded radio they can communicate on both 8.33 and 25 kHz channels.  The mode is determined by the channel the radio is tuned to. So it is important that a radio is used on the channel advertised by the ground station and references are regularly checked.

    The CAA has taken a pragmatic and proportionate view to enable the safe conversion of aircraft and ground stations, driven by the requirements of the IR and the European Commission.

    The permitted exemptions are the latest in a series of measures designed to encourage equipage in line with the requirements. In addition airspace users are permitted to use handheld radios in a number of circumstances as well as having access to a 20% rebate on new equipment and some associated accessories.

    We are aware that some states are also looking at deploying limited duration exemptions, and that others have already converted a majority of assignments. Ultimately all airspace users will have to equip and the CAA is keen to enable the benefits for all areas of aviation that implementation of 8.33 kHz VCS will bring. 

  • Change in the law

    The law is changing on the 1 January 2018. From this date, except for the UK’s temporary exemptions, all aircraft will be required to carry and operate aircraft radio equipment that has 8.33 kHz voice channel spacing (VCS) capability in airspace where the carriage of a radio is mandated. The UK leaving the EU will not affect the implementation of this new legislation.

    Aircraft owners are advised that if they are yet to equip they should pursue equipage as soon as possible to avoid aircraft operations becoming significantly restricted during 2018.

  • We have been encouraging GA aircraft owners to purchase 8.33 kHz radios as early as possible and secured EU funding to cover a 20% rebate on radio and associated equipment purchases. The scheme includes support for the purchase of handheld units which may offer an equipage option for some airspace users.

    The Innovation and Networks Executive Agency (INEA) awarded €4.3 million of EU funding for the CAA to use to assist the transition of aircraft to use 8.33 kHz voice communications. The funding will be distributed to aircraft owners or pilots to contribute toward the cost of new radio equipment.

    The third call period is now open and will run to 31 December 2017.

    The same eligibility criteria apply. Claims must be supported by receipts to show that payment for equipment has been made, and again, no pre-purchase funding claims are permitted.

    For more information on funding see our 8.33 kHz funding application page.


    UK adoption of 8.33 kHz VCS capable equipment is increasing, and feedback shows that over 50% of the UK GA fleet is already equipped, many successfully applying for funding. But we have recently become aware of aircraft equipage issues regarding the limited availability of installers. We have therefore agreed to invoke a number of limited time exemptions to provide flexibility for users and to help with the capacity issues that have been identified. The exemptions will run for 12 months to 31 December 2018.

    Exemptions cannot be applied to a specific aircraft. They are applied to specific assignments and can only be applied within the geographic area that the assignment covers. The CAA will enable exemptions on a number of common frequencies identified here: CAP 1606 Exempted Common Channels in the UK

  • There are a number of options for purchasing and installing equipment in time for the 8.33 kHz changeover deadline, including a number of ways the installation design approval can be simplified. Implementing Rule (IR) 1079/2012 says that radio equipment put into service after November 2013 should be 8.33 kHz voice communications system (VCS) capable and manufacturers must ensure radios placed on the market from this date meet this requirement.

    Backwards compatibility

    Users are reminded that new 8.33 compatible radios will retain the capability to communicate with existing 25 kHz ground stations before conversion takes place.

    Dual radios and existing 25kHz systems

    Aircraft will need to be equipped with the number of 8.33 kHz capable radios required by operational rules. So where the carriage of two radios is required, both radios must be 8.33kHz VCS capable.

    Non-commercial operations fall under Part NCO which does not include a requirement for aircraft to carry dual radios. But owners are advised to check the relevant regulation to their own operations in order to establish what is required.

    Existing 25kHz radios can be left installed provided that they are only used for exempted frequencies, such as the emergency frequency.

    Technical Standards Order (TSO)/European TSO (ETSO)

    Following an agreement between EASA and the FAA, each organisation now mutually recognises TSO/ETSO approvals for certain aircraft products, which includes VHF radio communications equipment. In Europe there is no longer a requirement for a manufacturer to separately approve a piece of equipment that holds a TSO; the equipment can be installed and used as if it has the corresponding EASA approval. Further details on the scheme are at EASA website.

    The CAA holds a list of common equipment, and the EASA and FAA lists can also be accessed online.

    LA3 approved equipment

    In certain circumstances the use of a LA3 approved 8.33 kHz radios may be appropriate. The CAA has issued an approval for handheld devices that meet certain stipulations.

    Pilot owners should obtain confirmation from the manufacturer that their radio meets the conditions of the Approval. Once confirmed, the pilot may then use the Equipment Approval LA301075 as the reference when applying to the CAA for their Aircraft Radio Licence, which is required by the Wireless and Telegraphy Act. We are aware of the following 8.33 kHz handheld radios that meet the specified requirements:

    • ICOM IC-A6E
    • ICOM IC-A24E
    • Yaesu FTA-550
    • Yaesu FTA-750
    • Yaesu FTA-450

    This is not an exhaustive list: there may be other models that meet the requirement. Above are those currently identified to the CAA by manufacturers.

    EASA aircraft

    Minor change: EASA aircraft can achieve a minor change approval to enable the replacement of a VHF radio. Minor changes can be approved by EASA and a radio manufacturer will often seek approval for a modification through EASA. The approval can then be re-distributed by the manufacturer to enable the minor change approval to be used by another individual. As the approval would be aircraft type specific, avionics manufacturers may hold minor change libraries for distribution to aircraft owners, licensed engineers and maintenance organisations.

    CS-STAN: Certification specification for standard changes and standard repairs (CS-STAN) is a new EASAspecification that enables owners of non-complex aircraft to benefit from a quicker approval process for the installation of certified avionics that includes VHF radios. CS-SC001a 'Installation of VHF voice communication equipment' enables, under certain conditions, the replacement of a radio through this route that can be used:

    • To exchange radio equipment on VFR/IFR aircraft.
    • For initial-installation of radio equipment for VFR aircraft only.
    • CS-SC001a does not include antennas. More detail is available from EASA.

    Broadly, CS-STAN approvals are applicable to aircraft operating under VFR that meet the following conditions:

    • Certified EASA aircraft below 5700kg.
    • Certified EASA helicopters below 3175kg.
    • Motor sailplanes, sailplanes and lighter than air types.

    Non-EASA/CAA-regulated aircraft

    Minor modification: Non-EASA aircraft can receive an equivalent to the above EASA Minor Change through a CAA minor modification approval.

    CS-STAN equivalent: CAA has provided a process to enable use of CS-STAN on non-EASA/CAA-regulated aircraft through publication CAP1419.

    Your aircraft maintenance organisation should be contacted for further guidance about installation and design certification.

  • Ground station conversions

    Ground stations will begin to convert to 8.33 kHz VCS during 2018. The conversion date will depend on the decision taken by each individual ground station. Airspace users are strongly advised to ensure they use up to date and accurate information before flying and follow any instructions given by units. 

    When your flight needs you to only communicate on 25 kHz frequencies, you will be able to continue to use your 25 kHz radio for a limited time period of 12 months (to 31 December 2018). However, when any ground station or service throughout your flight converts to an 8.33 kHz channel, you must only communicate on an 8.33 kHz capable radio.

  • Users are reminded that static data sources such as charts and aerodrome reference guides may be out of date during the transition. Radio presets and equipment databases will need to be kept up to date.

    If in doubt users are advised to ensure their radio is capable of tuning to the stipulated frequencies defined by the ground station facility. If unsure speak to the ground station facility before flying.  If a radio is unable to display or tune to the assignment listed then the radio should not be used to try and communicate with a particular facility or service.

    When your flight needs you to only communicate on 25 kHz frequencies, you will be able to continue to use your 25 kHz radio for a limited time period of 12 months (to 31 December 2018). However,when any ground station or service throughout your flight converts to an 8.33 kHz channel, you must only communicate on an 8.33 kHz capable radio.

    We will continue to liaise with ground station facilities and will consider additional exemptions for specific units on a case by case basis. Any ground stations requiring further assistance or advice should contact the 8.33 VCS National Coordinator by email: 833VCS-radios@caa.co.uk  

  • Updates

    Updates on the 8.33 kHz implementation project for GA will be published on this webpage.

    To keep up to date with developments you can sign up for alerts through our Skywise system, which offers targeted alerts on news and information from across the CAA. You can access this system through a free app, email or website. For more information on Skywise, to download the app or sign-up for alerts via email go to http://skywise.caa.co.uk/

    More detail and technical information

  • ECfunding