Bringing Home the Beacon

(Airwaves magazine - Issue 7, Winter 2009)

Emergency beacons, transmitting on the new 406 MHz frequency, reduce the search area by 97% which greatly increases not only your chance of being located - but also your chances of survival.

On the 1st February 2009, the international system of satellites used by global Search and Rescue organisations known as the COSPAS-SARSAT System, ceased processing emergency beacons transmitting on 121.5/243 MHz frequency and switched to a new, more accurate frequency of 406 MHz.

The decision to terminate 121.5/243 MHz processing was made in October 2000 at the 25th Session of the International COSPAS-SARSAT Council (CSC-25) and beacon owners worldwide are encouraged to replace their existing beacons with 406 MHz beacons.

121.5MHz and 243MHz beacons are now obsolete, unreliable technology. Rather than waste resources monitoring the old frequency, worldwide efforts are now being concentrated on the superior 406MHz system. COSPAS-SARSAT made the decision to cease satellite processing of 121.5MHz and 243MHz in response to guidance from the International Civil Aviation Organization (ICAO) and the International Maritime Organization (IMO).

 These United Nations organisations mandate safety requirements for aircraft and maritime vessels and have recognised the limitations of the 121.5MHz and 243MHz beacons and the superior capabilities of the 406MHz alerting system. It is faster, more reliable and more accurate, and is already assisting in the saving of lives.

The decision was also made to reduce the chronically high false alarm rate from analogue distress beacons. Prior to February 2009, 91% of distress beacon signals world-wide were false alarms.

Reducing the cost of false activations is one of the key benefits of 406MHz beacons. They do this by unique identification codes that are referenced against a registration database within individual countries, so that owners can be contacted to determine if activation is real or false and appropriate action quickly and efficiently deployed.

Only 406 MHz beacons are now detected by the COSPAS-SARSAT satellite system. This affects all maritime beacons (EPIRBs), all aviation beacons (ELTs) and all personal beacons (PLBs). However, other devices (such as man overboard systems and homing transmitters) that operate at 121.5 MHz and do not rely on satellite detection are not affected by the phase-out of satellite processing at 121.5 MHz

406MHz beacons are more accurate (to within approximately 5 km, compared to about 20 km for the analogue beacons). 406MHz beacons are also faster – depending on the location, they may be detected within minutes, compared to the average one hour and 30 minutes it takes to get confirmed satellite detection from a 121.5MHz or 243MHz analogue beacon. With the addition of GPS, your location can be determined to within 120 metres in a matter of minutes.

IT IS VITALLY IMPORTANT TO REGISTER YOUR BEACON

It is absolutely vital that you register your 406 MHz beacons with the Rescue Coordination Centre NZ and keep the information up to date. This service is free and confidential and registration can be done on-line, by email, fax, mail or telephone. Visit  www.beacons.org.nz  for all contact and registration details.

The information you provide will make the rescue faster and more effective - in some cases it has already saved lives that might otherwise have been lost. In one example, RCCNZ received an alert from an orbiting satellite that gave two possible positions, one at sea and one inland. Using the registration information, RCCNZ were able to find out that the beacon was owned by a hunter who was expected to be in the area of the land position. A SAR operation was arranged and the injured hunter picked up. He might not have survived if rescue teams had to wait for a second satellite pass to resolve his location.

How the 406MHz Beacon Monitoring System works

1. A distress beacon is activated.
2. The signal is transmitted to the nearest sub-orbital satellite. These can be satellites that remain in stationary position over the same area of the earth's surface or those that are constantly circling the earth in polar orbits.
3. The signal is transmitted from the satellites to the nearest local user terminal (LUT). These are placed around the globe, to ensure signals are received almost immediately.
4. The signal is passed to the Rescue Coordination Centre New Zealand, based in Wellington.
5. The RCCNZ mobilises rescue resources, normally from the closest available centre and directs them to the coordinates of the signal.
6. Search aircraft are normally fitted with DF (Direction Finding) equipment to guide them to the source of the signal.

The importance of correct beacon disposal

It’s important to dispose of your old 121.5 or 243MHz distress beacon properly. If you don’t, it could still be accidentally activated, causing an unnecessary search and rescue operation. Old beacons need to have their battery disconnected and then be disposed of in accordance with local regulation, as many contain hazardous materials.

To illustrate the need for correct beacon disposal, the New Zealand Rescue Coordination Centre recently sent the Wellington-based Westpac Rescue Helicopter on a mission to find the source of a signal from an old 121.5 MHz beacon which had been activated.

While the signal was no longer picked up by satellites, it was heard strongly by aircraft flying in and out of Wellington airport.

The Westpac crew tracked the signal to the Wainuiomata rubbish dump, where they narrowed down the search area to a within a few metres using a hand-held radio.

With the beacon buried beneath tonnes of rubbish, it had to be reached by digger and de-activated, otherwise it would have continued to operate for the life of the battery.

Since the introduction of the new frequency, there have been many such incidents of false alarms all over the country initiated by improper disposal of old equipment - each one involving a huge amount of operating resources and cost.

Old beacons should be disposed of properly by contacting the Rescue Coordination Centre New Zealand on 0800 406 111 to find out your nearest beacon disposal centre or by sending it to the Rescue Coordination Centre by courier, handing it in to your nearest Police station or handing it to the retailer from whom you purchase your 406 MHz beacon.

For a list of leading suppliers in New Zealand, go to www.beacons.org.nz

They are hard-wired into the aircraft and are fitted to activate on impact or can be activated manually.

What is a PLB?
Personal Locator Beacons (PLBs) are designed for personal use, mainly by trampers, cross-country vehicle clubs, mountaineers and other adventurers on land.

They can also be used in light aircraft, gliders, hot air balloons and in some maritime situations.
They’re small enough to fit in your pocket and are activated manually.

What is an EPIRB?
Emergency Position Indicating Radio Beacons (EPIRBs) are distress beacons designed for maritime environments.
They are waterproof and designed to float upright in water. Some require manual activation and have additional safety devices, such as strobe lights. Others are self-activating and will float free in the event of an emergency.
The battery life of an EPIRB is normally twice as long as a PLB.

Information from www.beacons.org.nz