Communication technology. If it saves one individual's life, it's worth it.
Besides messing with motorcycles, hot rods and airplanes, I'm also a rated pilot serving in the United States Air Force Auxiliary Civil Air Patrol. Many of our emergency missions are for missing and/or downed private aircraft.
Most, but not all, of these aircraft are equipped with an Emergency Locator Transmitter (ELT). The ELT is designed and installed so as to be activated upon impact. Often, just a hard landing will trigger the signal.
Aircraft ELTs transmit on 121.5 MHz or 243.0 MHz as do the EPIRBs.
ELTs (Emergency Locator Transmitter) signal aircraft distress.
EPIRBs (Emergency Position Indicating Radio Beacon) signal maritime distress. Often, these are attached to individual flotation devices or life rafts.
PLBs (Personal Locator Beacons) On 406 MHZ, are for personal use and are intended to indicate a person in distress who is away from normal emergency services such as 911.
In the case of the PLB 406 MHz beacons, which transmit digital signals, the beacons can be uniquely identified almost instantly (via the GEOSAR satellite), and furthermore, a GPS position can be encoded into the signal thereby providing both instantaneous identification of the individual along with an emergency contact telephone number and the individual’s position.
The basic purpose of all distress radio beacons is to get people rescued.
By 01 February 2009, the 121.5 and 243.0 MHz ELTs and EPIRBS will no longer be detected by the SARSAT (Search and Rescue) satellites although some ground stations may still monitor the frequency for a period of time.
Fly safe.
Monte Miller, Major
USAFAux