VHF Radio – 8.33kHz channel spacing

8.33 radios – mandatory in Europe

As European pilots are aware, after the 1st of January 2018 aviation radios must be 8.33kHz capable. Please see our FAQ’s below that were created around the time of the change. If you have an 8.33 question that is not an FAQ, why not ask our customer support team? Contact them here.

Background Information

It’s against the law in Europe to sell or fit a new radio in an aircraft that is not 8.33 capable. It is also worth remembering that radios used in Europe need to be certified too. This can impact on aircraft owners with EFIS systems, which have a facility to control a radio. Many of these systems are uncertified, they may be legal elsewhere, however within Europe they must use a certified controller. Some aircraft manufacturers have been able to authorise their selected installed avionics with a type approval.

For very light aviation, the CAA in the UK has negotiated an opt out, allowing the use of uncertified 8.33 radios (typically hand held units). Beware however, you will usually require a certified radio in Europe. An uncertified radio might not be legal for use outside of the UK, always check local regulations before you make your trip.

What does 8.33kHz channel spacing do?

The old 25kHz spacing has been divided by three.

25/3 = 8.33333. Now, there are lots more channels to use which will help congested airspaces.

How does this effect me?

8.33 is mandatory in Europe as of January 2018. if flying in controlled airspace in Europe, if you fly with a radio it must be an 8.33kHz radio.


What happens if I keep my 25kHz radio?

If you try to transmit on a 25kHz radio you could cause serious interference on adjacent channels for 8.33 radio users. You will not be able to tune to 8.33 frequencies, and so will not be able to communicate with many airfields and other aircraft.