ELT & PLB Info

Emergency Locator Transmitters, are tracking transmitters which aid in the detection and location of boats, aircraft, and people in distress. Strictly, they are radiobeacons that interface with Cospas-Sarsat, the international satellite system for search and rescue (SAR). When activated, such beacons send out a distress signal that, when detected by non-geostationary satellites (the old 121.5 ELT signal), can be located by triangulation. In the case of the new 406 MHz beacons which transmit digital signals, the beacons can be uniquely identified almost instantly via geostationary satellits, and furthermore, a GPS position can be encoded into the signal (thus providing both instantaneous identification and position). Often using the initial position provided via the satellite system, the distress signals from the beacons can be homed by SAR aircraft and ground search parties who can in turn come to the aid of the concerned boat, aircraft, or people.  The Cospas-Sarsat system operates 24 hours a day 365 days a year.

Due to the obvious advantages of 406 MHz beacons and the significant disadvantages to the older 121.5 MHz beacons, the International Cospas-Sarsat Program have made a decision to phaseout 121.5 MHz satellite alerting on February 1st, 2009.  All pilots are highly encouraged both by NOAA and by the FAA to consider making the switch to 406!

Cospas-Sarsat made the decision to cease satellite processing on 121.5/243 MHz in response to guidance from the International Civil Aviation Organization (ICAO) and the International Maritime Organization (IMO). These United Nations organizations mandate safety requirements for aircraft and maritime vessels and have recognised the limitations of the 121.5/243 MHz beacons and the superior capabilities of the 406 MHz alerting system.

The digital 406 MHz beacons offer many advantages over analog 121.5/243 MHz beacons. With a 406 MHz beacon, the position of the distress can be relayed to rescue services more quickly, more reliably and with greater accuracy.