406 MHz ELT News

Most everyone is aware that the International Cospas-Sarsat System terminated satellite processing of distress signals from 121.5/243 MHz emergency locator transmitters (ELT) on February 1, 2009. Distress signals on 121.5/243 MHz are now only detected by ground based receivers and other aircraft. Aviators will need to switch to an ELT operating at 406 MHz if they want to be detected by satellites.

At the time of this writing, the FAA has not mandated the use of 406 MHz ELTs for U.S. registered aircraft or other aircraft flying in U.S. airspace. Mexico will require them by April 2, 2010. The Bahamas has not implemented the requirement and will review the order again in February 2011. Canada has extended their requirement for 406 MHz ELTs in the southern part of the country until at least March 11, 2011. A 406 MHz ELT (or an alternate means of emergency location) is required when operating north of 55 degrees latitude in western Canada and north of 50 degrees latitude in eastern Canada.

Those not ready to install a 406 MHz ELT may wish to consider a Personal Locator Beacon (PLB). These are handheld devices that transmit distress signals on the 406 MHz frequency. They do not meet FAA ELT requirements, but when carried in conjunction with a standard, onboard 121.5/243 MHz ELT, can offer a little more peace of mind. Remember that PLBs will not automatically activate.

Here’s something to keep in mind; with an activated 121.5/243 MHz ELT, the typical search area may be a 15-20 kilometers radius. In a remote area, it is even possible for the signal to be undetected. A 406 MHz ELT tightens that radius to 1 – 2 kilometers. When coupled to the aircraft navigation system (GPS, etc.) the position accuracy improves to approximately 100 meters.

On June 15th, The Federal Communications Commission announced it will prohibit further certification, manufacture, importation, sale or use of 121.5 MHz emergency locator transmitters. The date of compliance has not yet been set by the FCC. The FCC has clarified that the rule is targeting legacy TSO C91a type ELTs, which operate primarily on 121.5 MHz. Current TSO C126 ELTs (406MHz) are not affected by this ruling, although most of them also transmit on 121.5 MHz.