Electronic conspicuity devices

In December 2022, we published a joint statement with the Department for Transport (DfT) on the development of a national specification for EC alongside a report commissioned by the DfT from Egis, an independent aviation consultancy .

We have always advocated for the development of a clear national specification for EC and support the recommendations included in the Egis report for aircraft to be equipped with regulated EC devices that meet the proposed specifications. The potential volume and intensity of future air operations in the UK requires a step change in how airspace users safely operate in relation to each other, this EC work is a step towards understanding how that will work and supports the integration of airspace users as described in the Airspace Modernisation Strategy.

CAP 1391 sets out the expectation that any device using ADS-B on 1090MHz must have a Declaration of Capability and Conformance from the manufacturer before being used onboard an aircraft. The pilot in command of the aircraft is responsible for ensuring that the EC device has a valid declaration.

Declared devices

EC devices use a 24-bit aircraft address (AA), (also known as a hex address) for receiving systems to differentiate them from other EC devices. A unique ICAO 24-bit AA will be allocated as part of an aircraft’s Certificate of Registration. However, as some EC devices are portable and may be used by unregistered aircraft, the 24-bit AA may be programmable by the user. You can find details on how to perform this function in your EC device's operating handbook.

For use on an unregistered aircraft

If you are using a 1090ES EC device with a valid declaration on an unregistered aircraft, you should contact the National IFF/SSR Committee secretary and provide the following:

• Your contact details and UK postal address
• The details for your EC device, including: Make, Model and Serial number
• Brief description of how the device will be used (e.g. on multiple unregistered aircraft)

Where appropriate, the NISC will allocate the EC device a unique ICAO 24-bit AA. Allow 4 weeks for the CAA to allocate a 24-bit AA.

For use on registered aircraft

If you are using your EC device on a registered aircraft with an existing ICAO 24-bit AA, then this address shall be used.

If you need to move the device between registered aircraft, it must be reprogrammed with the new aircraft's ICAO 24-bit AA (as appropriate).

Selling your device

If you sell your EC device, you need to clear any registered aircraft ICAO 24-bit AA before the sale. The new purchaser must contact us with their contact details and we will issue a unique ICAO 24-bit AA if necessary.

To use a 978 MHz Universal Access Transceiver device on unmanned aircraft in the specific category, operators should ensure the device meets the standards prescribed in RTCA DO-282B/C except that where Mode A codes (squawks) are used for flights in the UK, they should adhere to the UK AIP ENR 1.6

The UAT device must be capable of generating a self-assigned temporary Aircraft Address. These will be pseudo-randomly generated each time the device is switched on as per RTCA DO-282B/C. The device will only generate an AA after a GNSS position has been fixed due to the algorithm requiring time, latitude and longitude to generate the AA. The device must have the address qualifier set to 001 indicating that the 24-bit address is NOT an ICAO address. The CAA will not allocate a permanent ICAO 24-bit aircraft address (ADDRp) to UAT devices.

Whilst duplication of self-assigned temporary AAs is highly unlikely, caution should be advised when switching on multiple devices. Due to the time/latitude/longitude randomiser algorithm, devices should not be switched on within 3 metres of each other within the same second.

Any observed duplication of AAs should be reported to the CAA here.

To operate any radio equipment, aircraft owners/operators must hold a valid Wireless Telegraphy Act (WTA) Aeronautical Radio Licence. 1090 MHz EC devices are radio-transmitting equipment, so are subject to this regulation.

The WTA usually requires anyone operating a transmitter/receiver, on this frequency, to have or be under the direct supervision of someone who possesses a Flight Radio Telephony Operator's Licence or FRTOL. This was because when this radio licence condition was introduced, it was assumed that all aircraft radio stations would include a voice telephony function.

A General Exemption has been issued so that while a WTA licence is still needed, the pilot does not need a FRTOL if the transponder is the only radio equipment on the aircraft.

When purchasing an EC device, it is the responsibility of the aircraft owner/operator to complete the relevant application form to obtain a WTA Aircraft Radio Licence from Ofcom.