This article was accepted into the corpus but its outbound wikilinks were never NER-processed — typical at the deepest BFS hop or when the run's entity cap was reached. No expansion funnel to show.
| personal locator beacon | |
|---|---|
| Name | Personal locator beacon |
| Invented | 1970s |
| Manufacturer | ACR Electronics, McMurdo Group, ARTEX, Garmin Ltd., Ocean Signal |
| Introduced | 1970s |
| Type | Distress radio transmitter |
| Uses | Search and rescue, maritime safety, aviation emergency signaling |
personal locator beacon
A personal locator beacon (PLB) is a portable emergency radio transmitter carried by individuals to summon search and rescue (SAR) resources when in distress. It transmits a coded distress signal and often precise position data via satellite and terrestrial radio networks to alert SAR agencies such as National Search and Rescue Plan, United States Coast Guard coordination centers, and regional rescue services. PLBs are used by mariners, aviators, hikers, and expedition teams and integrate with international systems including COSPAS-SARSAT, Global Positioning System, and regional satellite constellations.
PLBs are part of a family of emergency beacons that includes maritime EPIRB units and aviation ELT devices. Typical PLBs broadcast on internationally recognized distress frequencies, most notably 406 MHz through the COSPAS-SARSAT satellite system, and often provide a backup 121.5 MHz homing signal for local SAR units such as United States Air Force rescue squadrons, Royal Air Force search and rescue units, and volunteer organizations like Royal National Lifeboat Institution. Many PLBs incorporate GPS receivers tied to the Global Positioning System constellation to embed location coordinates in the distress message, facilitating rapid vectoring by coordination centers including Joint Rescue Coordination Centre facilities.
Developed in the 1970s alongside early satellite SAR experiments, PLBs evolved from maritime emergency beacons used by navies and commercial fleets including United States Navy operations and research programs. The establishment of the COSPAS-SARSAT program by Canada, the United States, France, and the Soviet Union accelerated standardization of 406 MHz beacons. Later milestones include adoption of GPS-equipped PLBs following commercialization of Global Positioning System access in the 1990s and certification regimes established by agencies such as the International Civil Aviation Organization and the International Maritime Organization to harmonize distress signaling standards.
A PLB typically comprises an antenna, transmitter, battery pack, control interface, and GPS receiver. The transmitter downlinks a digitally encoded distress packet conforming to COSPAS-SARSAT protocols; the encoding includes a unique beacon identifier registered with national authorities like Beacon Registration Database operators such as the United States National Oceanic and Atmospheric Administration and counterparts in Australian Maritime Safety Authority. Housing materials are chosen for buoyancy and durability standards set by bodies such as International Electrotechnical Commission. Some models add features from manufacturers like ACR Electronics and ARTEX, including strobe lights, water-activated switches, and integrated emergency position indicating radio beacons used in conjunction with Search and Rescue Satellite-Aided Tracking.
Activation can be manual or automatic depending on design. Manual activation is performed by the carrier in an emergency, while some PLBs include water-sensing or impact switches inspired by ELT automatic triggers used in aviation incidents such as Dana Air Flight 994. When activated, the PLB transmits the beacon ID and, if available, GPS-derived coordinates to COSPAS-SARSAT satellites; data are relayed to Mission Control Centres and forwarded to Rescue Coordination Centres such as the United States Rescue Coordination Center, Joint Rescue Coordination Centre Halifax, or national SAR agencies. First responders dispatch assets that may include Coast Guard Air Station helicopters, naval vessels, mountain rescue teams affiliated with groups like Mountain Rescue England and Wales, or volunteer SAR teams coordinated by organizations such as SARA.
International and national standards prescribe frequencies, encoding, and performance. The 406 MHz frequency band is mandated by COSPAS-SARSAT for satellite detection, while 121.5 MHz and 243 MHz are reserved for homing and military monitoring as per allocations by the International Telecommunication Union. Certification criteria are published by standards bodies including the European Telecommunications Standards Institute and the International Organization for Standardization; equipment must meet environmental and radiated power requirements defined in specifications like ITU Radio Regulations. Registration of beacon identities with authorities such as the United States National Oceanic and Atmospheric Administration or Australian Maritime Safety Authority is legally recommended or required in many jurisdictions.
PLBs have been credited with successful rescues in remote incidents involving Everest Base Camp expeditions, small-boat dismastings off coasts like Cape Horn, backcountry aviation crashes near locations such as Denali National Park and Preserve, and wilderness getaways in regions including Scottish Highlands. Integration of GPS dramatically reduces search areas from square kilometers to tens of meters, improving SAR response times for units such as Air National Guard helicopter crews and volunteer search teams. Studies by agencies like COSPAS-SARSAT and national SAR authorities demonstrate high positive outcomes when PLBs are properly registered and used according to protocols.
PLBs are limited by battery life, antenna orientation, obstruction by terrain or structures (for example in canyons or dense forests), and satellite geometry during transmission windows. False alerts—whether accidental activations or intentional misuse—consume SAR resources and have prompted legal actions by entities including United States Coast Guard and civil courts under statutes enforced by national authorities. Unauthorized replication of beacon identifiers or failure to maintain registration can complicate incident response. Users must be aware of restrictions in airspace and maritime zones overseen by agencies like Federal Aviation Administration and International Maritime Organization guidance when carrying or activating a PLB.
Category:Emergency communication equipment