Switzerland and the Principality of Liechtenstein
Radio Interface Regulation

784.101.21 / RIR01041)
Aeronautical emergency

406 / 121.5 / 243.0 MHz
Edition 2.1 / 01.01.2021

Nr Parameter2)DescriptionComments
1Radiocommunication serviceMobile-satellite (Earth-to-space)-
2ApplicationELTRIR0104-01 applies to ELT (Emergency Locator Transmitter) used in civil aviation and carried in aircraft with no ELT requirement.
The ELT shall be activated by shock crash sensor (G-switch) or manually in a distress situation only.
The 406 MHz ELT shall be coded with the coding options according to COSPAS-SARSAT guidelines.
Refer to document TM 20.140-01 of the Swiss Federal Office for Civil Aviation (FOCA) for ELT to be installed in aircraft with an ELT requirement.
3Frequency bandA: 406.00 - 406.10 MHz
B: 121.45 - 121.55 MHz
C: 242.95 - 243.05 MHz
Band A: 406 MHz alert frequency for COSPAS-SARSAT satellite service.
Band B: 121.5 MHz homing frequency.
Band C: 243.0 MHz homing frequency.
5Modulation / Occupied bandwidth--
6Direction / Separation--
7Transmit power / Power densityMax. 5 W e.i.r.p. (406 MHz).
Max. 100 mW e.r.p.e.p. (121.5 / 243.0 MHz).
Min. 1.58 W e.i.r.p. for ELT (406 MHz).
Min. 25 mW e.r.p.e.p. (Effective Radiated Peak Envelope Power) for the VHF homing transmitter (121.5 / 243.0 MHz).
8Channel access and occupation rules--
9Authorisation regimeSwitzerland: Notification required.
Liechtenstein: Individual assignment required.
Aircraft radio equipment is listed in the 'Aircraft station license'.
406 MHz ELT have to be registered at the Swiss Federal Office for Civil Aviation (FOCA). (FOCA registration form: https://www.bazl.admin.ch/bazl/de/home/fachleute/luftfahrzeuge/luftfahrzeugregister/hb-luftfahrzeugregistergeschaefte--ein-ueberblick.html).
10Additional essential requirements--
11Frequency planning assumptions--
12Planned changes--
13ReferenceEN 300 066, EN 300 152 /-/-.
or the relevant aviation requirements. (Reference Comments).
Effective use of spectrum / ECC Decisions / ECC Recommendations.

Aviation requirements:
TM 20.140-01 (121.5 MHz / 406 MHz)
Requirement for 121.500 MHz:
TSO-C91a or JTSO-2C91a
DO-183 of RTCA and ED.62 of EUROCAE
Requirement for 406 MHz:
TSO-C126 / JTSO-2C126
DO-182 / DO-204 of RTCA and ED.62 of EUROCAE
14Notification number2009/9501/CH
15RemarksIf an ELT is not mandatory, pilots may use a PLB coded with the owners identification.Pilots may use a PLB (Personal Location Beacon) as an alternative to ELT when an ELT is not mandatory. A PLB can be carried additionally to a mandatory ELT.
The PLB shall be coded with the owners identification and the country code according to the registration. (For PLB refer to [RIR0504-02])
Current 121.5 MHz ELT do not transmit owner or aircraft coding and are not supported by COSPAS-SARSAT satellite system.

Normative part: 1 to 11
Informative part: Nr 12 to 15

1) RIR for similar and/or other applications are available under: https://www.bakom.admin.ch/bakom/en/home/frequenzen-antennen/nationaler-frequenzzuweisungsplan/schnittstellen-anforderungen.html
2) For explanations and legal status, please refer to basis document 784.101.21 / RIR0000