Switzerland and the Principality of Liechtenstein
Radio Interface Regulation

784.101.21 / RIR01041)
Aeronautical emergency

406 / 121.5 / 243.0 MHz
Edition 2.0 / 01.08.2018

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 regimeRegistration of 406 MHz ELT is mandatory.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)
The ELT shall also be notified to OFCOM in order to enclose it in the aircraft radio license. (OFCOM registration form: https://www.bakom.admin.ch/bakom/de/home/frequenzen-antennen/frequenznutzung-mit-oder-ohne-konzessionen/flugfunk.html)

Use of 406 MHz, 121.5 MHz and 243 MHz ELT:
Switzerland: License exempt.
Liechtenstein: General authorisation.
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