The radio systems used in aviation are divided, on the basis of the place of use, to ground-based radio equipment and radio equipment used on board an aircraft. In addition, there are portable radio equipment which can be used both on ground and on board airborne aircraft in accordance with the conditions of the radio licence. Radio licences are granted only for equipment that meet the requirements.
The user of a radio transmitter must have a special rating, issued by the Traficom, for operating aeronautical radio communication.
Ground-based radio equipment
Ground-based radio equipment are radio equipment used on ground or on board aircraft on ground. Ground-based radio equipment and their operational frequencies are presented in the table below:
|Beacon (Non-directional radio beacon (NDB), inner/outer approach beacon)||255.000–495.000 kHz|
|Voice radiocommunication (VHF COM)|
(VHF base station transmitter, VHF multi-channel transmitter, VHF standby transmitter, portable radiotelephone, vehicular station)
|ILS marker transmitter (outdoor marker/middle marker transmitter)||75.000 MHz|
|ILS localizer (LLZ)||108.100–111.950 MHz|
|VHF omnidirectional radio range (VOR)||111.975–117.975 MHz|
|ILS glide path transmitter (GP)||328.600–335.400 MHz|
|Distance measuring equipment (DME)||962.000–1213.000 MHz|
Uncontrolled aerodromes, i.e. so-called backwoods airfields, are aerodromes without air traffic control. The use of radio equipment in aerodromes like these (e.g. in private aviation, hang glider towing) on frequencies intended for aviation requires a radio licence. The radio licence entitles to use radio transmitters on all uncontrolled aerodromes in Finland on frequencies allocated in the Aeronautical Information Publication (AIP), part AD2 EFXX (External link).
Air competitions require a radio licence. The radio licence entitles to use radio transmitters in competitions on a frequency allocated for competition operations.
Aeronautical portable radio equipment
Handphones which operate on VHF frequencies intended for aviation and which may be used, according to licence conditions, both on ground and on board airborne aircraft (e.g. aeroplanes, hot-air balloons, hang gliders) are called as aeronautical portable radio equipment.
Aeronautical portable radio equipment can be used, for example, in conjunction with hang glider towing or paragliding. Therefore, the use of the equipment differs from the use of ground-based radio equipment. The use of ground-based radio equipment usually requires frequency planning.
If a VHF handphone is a permanent part of the aircraft's radio station, the radio station is reported in the radio licence application for the aircraft.
Radio equipment on board aircraft
All radio equipment on board aircraft constitute the radio station of the aircraft. Examples of radio equipment used on board aircraft are
- Distance measuring equipment (DME)
- Cospas-Sarsat emergency location transmitter (ELT)
- Radioaltimeter (RAM)
- Satellite telephone (SATCOM)
- Traffic collision avoidance system (TCAS)
- Transponder (TRP)
- Aeronautical VHF radiotelephone (VHF AER)
- Weather radar (WRD)
- Doppler navigator (DNV)
- Emergency radio telephone (ERT)
- Aeronautical HF radiotelephone (HF).
In some cases, the radio station on board an aircraft can also contain a VHF radiotelephone operating on maritime frequencies. This concerns primarily aircraft intended for maritime rescue.
Unmanned Aircraft Systems (UAS)
The topic is covered in detail on page Drones and remotely piloted aircraft (UAS/RPAS) - frequencies and radio licences .
Licence-exempt radio frequencies
Licence-exempt radio transmitters may be used in aviation, if the requirements set for radio transmitters are fulfilled.