ELT’s (Emergency Locator Transmitter) Do You Need One?


Firstly what is an ELT?

ELTs are emergency transmitters that are carried aboard most general aviation aircraft. In the event of an aircraft accident, these devices are designed to transmit a distress signal on 121.5 and 243.0 MHz frequencies, and for newer ELTs, on 406 MHz. ELTs are mounted aft in the aircraft, and designed to be triggered upon impact or may be manually activated using the remote switch and control panel indicator in the cockpit. Activation of the ELT triggers an audio alert, and 406-MHz ELTs transmit GPS position for search and rescue.

ELTs were originally intended for use on the 121.5 MHz frequency to alert air traffic control and aircraft monitoring the frequency. In 1982, a satellite-based monitoring system was implemented, COSPAS-SARSAT, to provide a better way to detect these distress signals. In 2009, the international COSPAS-SARSAT satellite system discontinued satellite-based monitoring of the 121.5/243 MHz frequencies, in part because of a high number of false signals attributed with these frequencies. Satellite monitoring today utilizes the 406 MHz frequency only.

Is an ELT required by law in South Africa?

Aircraft that are to be operated on extended flights over water or over areas where search and rescue would be especially difficult are mandated to carry at least one automatic ELT.

Aircraft engaged in a domestic-only general aviation operation using an aeroplane with a maximum certificated mass exceeding 5 700kg’s and any international general aviation operation are also mandated to carry at least one automatic ELT.

So simply put if you are flying an aircraft with a certified mass lower than 5700kg’s and you don’t intend to fly out the country’s borders you are not legally bound to install an ELT. It must also be kept in mind that the older 121.5 MHz, although monitored, are no longer SACAA approved.

The benefits of having an ELT in the case of an accident.

Pilots are trained to operate aircraft safely to avoid having accidents; nevertheless, flying has always been inherently risky; thus, accidents have and will continue to happen. In a study of 647 accidents that occurred in Alaska between 2004 and 2009, Swartz reported 12 of the 133 lives that were lost might have been saved had the aircraft been equipped with a 406 MHz Emergency Locator Transmitter (ELT); when activated, they help search crews rapidly locate the downed aircraft to rescue any survivors.

Alternative technologies.

While ELT technology and certification has evolved slowly over the years, new technologies that utilize satellite communication networks have made products available that are designed for both tracking and distress alerting.

Devices such as SPOT and Garmin Inreach provide tracking and distress alerting, but must be manually activated. Other systems, such as Spidertracks, provide automated alerting which is triggered if the tracking signal stops without proper shut-down notification.

In the latter case, the loss of signal from an aircraft crash or mishap would trigger the distress call, rendering the issues of the system’s post-crash survivability and activation a moot point. While these devices are not certified by the CAA, or replace the legal requirement for an ELT, aircraft owners may want to investigate them as a safety enhancement in place of equipping with a 406 MHz ELT.

False Alerts on ELT’s

Aeronautical Search and Rescue Coordination Centre, which operates under Air Trafic & Navigation Services, is responsible for coordinating search and rescue activities in the Southern African region. This agency is alerted to an ELT activation and determines an appropriate response, sometimes resulting in the South African Airforce, and other first responders initiating a search. ASRCC specialists put in considerable research and man-hours to track down the ELT and owner. Each activation is treated as an emergency so each false alert is a distraction and negatively affects other search and rescue missions. About 90% of false alerts occur because of beacon mishandling during the testing and maintenance of these systems.

Bottom line is that having a properly installed and functioning ELT could be the difference between you surviving a crash and you ending up dying a very painful slow death after a very traumatic crash as a result of not being found by rescue personnel. The choice is yours !!!


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