NOAA 99-075
Contact: Pat Viets


The International Cospas-Sarsat Program, a program that uses a satellite constellation that relays distress alerts to search and rescue authorities, has announced it will terminate satellite processing of distress signals from 121.5/243 MHz emergency beacons. Mariners, aviators, and individuals using emergency beacons will need to switch to those operating at 406 MHz if they want to be detected by satellites.

The termination of the 121.5/243 processing will happen over a period of time. It is expected to take place far enough into the future to avoid a crisis for persons now using these beacons. The Cospas-Sarsat Program is currently working on the details of the transition, including the time frame. Although no effective date has been set, the Cospas-Sarsat Program has decided that the 121.5/243 MHz instruments will not be carried on the next generation of satellites -- starting in 2006 for Russian satellites and 2009 for the U.S. satellites, operated by the Commerce Department's National Oceanic and Atmospheric Administration.

The Cospas-Sarsat Program made this decision, in part, in response to guidance from the International Maritime Organization and the International Civil Aviation Organization. These two agencies of the United Nations are responsible for regulating the safety of ships and aircraft, respectively, on international transits, and handling international standards and plans for maritime and aeronautical search and rescue. More than 180 nations are members of IMO and ICAO.

Another major factor in the decision to stop processing 121.5 MHz signals is due to problems in this frequency band which inundate search and rescue authorities with false alerts, adversely impacting the effectiveness of lifesaving services. Although the 406 MHz beacons cost more, they provide search and rescue agencies with more reliable and complete information to do their job more efficiently and effectively.

NOAA, along with the United States Coast Guard, United States Air Force and the National Aeronautics and Space Administration, are responsible for implementing the Cospas-Sarsat Program at the national level in the United States.

The implication of this Cospas-Sarsat decision is that users of beacons that send distress alerts on 121.5 and 243 MHz should eventually begin using beacons operating on 406 MHz if the alerts are to be detected and relayed via satellites. Meanwhile, anyone planning to buy a new distress beacon may wish to take the Cospas-Sarsat decision into account.

The three types of beacons in use are: emergency locator transmitters (ELTs), used on airplanes; emergency position-indicating radio beacons (EPIRBs), used on boats; and personal locator beacons (PLBs) used by land-based persons such as hikers.