Termination of 121.5 MHz Beacons for Satellite Alerting is Coming Soon
Notice Number: NOTC0981


On 1 February 2009, the International Cospas-Sarsat [1] Organization (U.S. included) will terminate processing of distress signals emitted by 121.5 MHz Emergency Locator Transmitters (ELTs). This means that pilots flying aircraft equipped with 121.5 MHz ELTs after that date will have to depend on pilots of over flying aircraft and or ground stations monitoring 121.5 to hear and report distress alert signals, transmitted from a possible crash site.

Why is this happening?

Although lives have been saved by 121.5 MHz ELTs, the downside has been their propensity to generate false alerts (approximately 98 percent of all 121.5 MHz alerts are false), and their failure to provide rescue forces with timely and accurate crash location data. Both of which actually delay rescue efforts and have a direct effect on an individual's chance for survival. Rescue forces have to respond to all 121.5 MHz alerts to determine if they are real distress alerts or if they are being generated by an interferer, an inadvertent activation (by the owner) or equipment failure.

Is there an alternative?

Yes, the Cospas-Sarsat System (U.S. included) has been and will continue processing emergency signals transmitted by 406 MHz ELTs. These 5 Watt digital beacons transmit a much stronger signal, are more accurate, verifiable and traceable to the registered beacon owner (406 MHz ELTs must be registered by the owner in accordance with Federal Communications Commission (FCC) regulation). Registration allows the search and rescue authorities to contact the beacon owner, or his or her designated alternate by telephone to determine if a real emergency exists. Therefore, a simple telephone call often solves a 406 MHz alerts without launching costly and limited search and rescue resources, which would have to be done for a 121.5 MHz alert. For these reasons, the search and rescue community is encouraging aircraft owners to consider retrofit of 406 MHz ELTs or at a minimum, consider the purchase of a handheld 406 MHz Personal Locator Beacon (PLB) which can be carried in the cockpit while continuing to maintain a fixed 121.5 MHz ELT mounted in the aircraft's tail.

Remember, after February 1, 2009, the world-wide Cospas-Sarsat satellite system will no longer process 121.5 MHz alert signals. Pilots involved in aircraft accidents in remote areas will have to depend on pilots of over flying aircraft and or ground stations to hear emergency ELT distress signals. For further information concerning the termination of 121.5 MHz data processing visit www.sarsat.noaa.gov