How An EPIRB, PLB, or ELT Rescue Works



How An EPIRB, PLB, or ELT Rescue Works

There are three types of beacons that work directly with the international Search and Rescue Satellite System known as Cospas-Sarsat, each with uniquely designed for the type of application: Emergency Locator Transmitters (ELTs) used by the aviation community, Emergency Position Indicating Radio Beacons (EPIRBs) used in the maritime environment, and Personal Locator Beacons (PLBs) used by individuals in multiple outdoor activities.

When activated, ELTs, EPIRBs, and PLBs send a unique distress signal on the 406 MHz frequency to the Search and Rescue Satellites. Each beacon is programmed with and sends a unique digital code called a HEX ID or Unique ID. The HEX ID identifies the type of beacon and, Search and Rescue use the HEX ID to identify the beacon registration information provided by the beacon owner. This information can include: who the beacon owner is, the type of aircraft or vessel the beacon is associated with (for ELTs and EPIRBs), emergency points of contact, flight plans, float plans and trip plans, and much more.

After the satellite receives a beacon signal, it relays the signal to ground stations referred to as local user terminals (LUTs). The LUT processes the data, computes the location of the distress beacon, and transmits a decoded alert message to its associated national Mission Control Center (MCC). This happens almost instantaneously after the initial beacon signal is received.

The Misson Control Center then automatically performs matching and merging of alert messages with other received messages, geographically sorts the data, and transmits a distress message to the closest appropriate SAR authority such as a national Rescue Coordination Center (RCC), a foreign SAR Point of Contact (SPOC) and another MCC if the beacon is for example registered to another country. The RCC investigates the beacon alert and launches rescue assets to find the parties in distress if the distress is deemed authentic. This can happen much quicker when the beacon is properly registered.

Rescue Overview

  1. 406 MHz Distress Call Is Activated
  2. Search and Rescue (SAR) satellites forward distress signal down to earth Ground Stations called Local User Terminals (LUT)
  3. Ground stations forward the distress to the Mission Control Centers (MCC)
  4. The MCC alerts the closest Rescue Coordination Centers (RCC)
  5. The RCC call emergency contacts and dispatch the closest SAR teams
  6. SAR teams arrive on scene and rescue survivors

Lives Saved Since 1982

  • Worldwide – Over 48,000+ people rescued
  • United States – 9,753 people rescued