Personal Locator Beacons

Personal Locator Beacons

If you're out of mobile phone coverage, a PLB would save your skin

Personal Locator Beacons 

Personal Locator Beacons

Personal Locator Beacons, or PLBs, are only recently available for use on land, but the technology used in Land PLBs has been around for maritime and aviation use since about 1982.  PLBs belong to a family of distress beacons that are run using the Cospas-Sarsat system, which is an international organisation whose mission is provides accurate, timely, and reliable distress alert and location data to help search and rescue authorities assist persons in distress.

The system became operational in 1985, has approx 1 million units, and has assisted in tens of thousands of rescues all over the world.  When activated, PLBs transmit a radio signal on the 406 MHz frequency to specific Cospas-Sarsat orbiting satellites which then relay information, via ground tracking stations and Mission Control Centres (MCC), to the UKMCC and co-located Aeronautical Rescue Co-ordination Centre (UK ARCC), at Kinloss, in NE Scotland, who in turn will contact the Police and Mountain Rescue.  In the case of the UK, this centre is the Aeronautical Resource Co-ordination Centre at RAF Kinloss in Scotland.

Most PLBs are also equipped with GPS receivers, thus being able to calculate and send an accurate location embedded within the beacon’s 406 MHz databurst message.  Other PLBs without integrated GPS rely solely upon the less accurate Doppler principle to establish the beacon’s position. The beacons also transmit a homing signal on VHF, to which SAR helicopters can home, once the 406 MHz component puts them in the vicinity of the beacon. All Cospas-Sarsat approved PLBs conform to the same international standard.

There is no doubt that carrying a PLB in a remote area is an advanced safety system, especially for the lone walker who may often be out of mobile phone network coverage.  PLB distress alert transmissions go initially to the UKMCC who will interrogate the registration database, try to establish whether or not the alert is real or accidental, and pass on to the Police and relevant SAR agencies.

Once a PLB unit is bought, there are no subscription fees and the battery should last, if not used, for 5 or 6 years..  However, you must register the PLB with the Marine Coastguard Agency ( and maintain accurate registration details, including the 24-hour Emergency Point of (EPOC) details.   Thus, when a beacon is activated,  vital information can be gleaned from the EPOC as to route, number in party, experience, clothing colours, etc. The EPOC will often be crucial in establishing whether or not a beacon activation is real or false, thereby avoiding costly and unnecessary SAR asset tasking.

Batteries for PLBs last approx 5 years before needing to be replaced by the manufacturer.

PLBs take the ‘search’ out of ‘search and rescue’.

UK Rescues

There has been at least one UK land based rescue as a result of a PLB activation. Read here.