MART Vol. II MO/MP - NESA - Civil Air Patrol

7.1 ELTs and SARSATElectronic equipment and procedures are used in general searches to focusthe search and rescue effort in a specific area, or as an alternative to visualsearches when visibility is reduced by weather or other atmospheric conditions.Equipment used in these searches may include a battery-powered emergencylocator transmitter (ELT) aboard the incident aircraft, search and rescue satellites,and an ELT receiver aboard the search aircraft.7.1.1 ELTsThe Federal Aviation Administration (FAA) requires most U.S.-registeredaircraft to have operable ELTs installed, which activate automatically whensensing acceleration forces during an accident. An active ELT transmits acontinuous radio signal on a specific frequency until it’s either deactivated or itsbattery discharges.Most general aviation aircraft have ELTs that transmit on 121.5 MHz at 60-100 milliwatts (less power than a small flashlight). They are activated by G-forcesor by manual operation of a switch (some aircraft have a remote switch in thecockpit). Space-based monitoring of 121.5 MHz ELTs ceased on 1Feb09.Advanced ELTs that transmit on 406.025 MHz at 5 watts are specificallydesigned to operate with the SARSAT/COSPAS satellite system. They alsoproduce standard sweep tones on 121.5, 243.0 and 406 MHz, and may transmitGPS coordinates. The registered transmitter sends a coded signal that can beused to obtain the owner's name, address and type of aircraft, so AFRCC can callthe number to see if the aircraft is really missing (~ 70% of the false alerts will beresolved by this call). Since geostationary satellites process the signal it will beheard more quickly and allow a much faster response (~ 6 hours saved). If theunit has a GPS receiver, it can transmit lat/long coordinates to further speed thesearch. The signal can also penetrate dense cover (e.g., trees). [Adoption of thethese ELTs will be slow by general aviation as they presently cost about threetimes as much as a 121.5 MHz ELT.]Military Beacons (e.g., URT-33/C) operate on 243 MHz. Personnelejecting/parachuting from a military aircraft have this beacon; some pilots may beable to communicate via two-way radio on 243 MHz using a PRC-90 or latermilitary survival radio (this radio also has a beacon mode).Marine Emergency Position Indicating Radio Beacons (EPIRBs) are primarilyfound on boats and ships. Similar to 406 or 121.5 MHz ELTs, some areautomatically activated while others can only be activated manually.Personal Locator Beacons (PLBs) and Personal Emergency Transmitters(PETs) use a 406 MHz transmitter and a 121.5 MHz homing signal (at only 25mw). Many are also equipped with a built-in GPS receiver that provides lat/longcoordinates (typically to within 98 feet). Each PLB must be registered.Practice beacons used by CAP transmit on 121.775 MHz. Avoid calling thepractice beacon an "ELT" while communicating on the radio; this can causeconfusion. The term "practice beacon" is very clear to all concerned and shouldbe used on all drills and exercises.ELTs can (and are) be inadvertently activated. Typical causes areexcessively hard landings (Welcome aboard, Ensign!), inadvertent manual116