Emergency Procedures resources

Emergency Procedures

Distress beacons

Types of beacon

406 MHz beacons are either GPS or non-GPS capable. GPS 406 MHz beacons provide an encoded (GPS) location that enables the COSPAS-SARSAT satellite system to calculate the beacon’s location much faster than for that of a non-GPS 406 MHz beacon.

There are three types of distress beacons:

  • Emergency locator transmitter (ELT) — for use in aircraft;
  • Personal Locator Beacon (PLB) – used by bushwalkers, drivers of cross-country vehicles, and other adventurers on the ground, as well as employees working in remote areas and crew in watercraft and aircraft
  • Emergency position indicating radio beacons (EPIRB) – normally used in ships and boats but also used in life rafts.

ELTs must operate continuously for at least 24 hours once activated. ELTs are usually fixed in the aircraft and are designed to activate on impact. However, PLBs or EPIRBs can be carried in an aircraft (other than the aforementioned ’exempted’ aircraft) as an alternative to an ELT (see CAR 252A).

PLBs are designed for personal use in both land and marine environments. This type of beacon is becoming a multi environment beacon. PLBs must also operate for a minimum of 24 hours once activated.

EPIRBs are designed to float in the water to optimise the signal to the satellite. An EPIRB must operate for a minimum of 48 hours continuously once activated. An EPIRB has a lanyard that is used to secure it to something that is not going to sink. There have been a number of incidents where vessels have sunk quickly and crew have not been able to deploy an EPIRB. In such incidents, float-free EPIRBs could have reduced response times and saved lives. Float-free EPIRBs are held in a bracket and fitted with a water-activated hydrostatic release, deploying the beacon automatically if the vessel sinks. If the vessel continues to float the EPIRB can be manually deployed.

Emergency beacons

Emergency position indicating radio beacon
Emergency locator transmitter
Personal locator beacon
Search and rescue


The following ELTs must meet the specified requirements to be an eligible ELT for use on an aircraft:

Eligible ELTs

ELTs Requirements to be eligible
Frequency MHz TSO (for battery)
ELT 406–406.1, 121.5 If fitted with a Li-SO2 battery, a type authorised by the FAA in accordance with TSO-C142 or TSO-C142a

For an ELT to be an approved ELT for the use on aircraft, it must be an eligible ELT and also meet the following requirements:

Approved ELTs

Eligible ELTs Requirements to be approved
Stowage Activation Beacon type Duration of operation Signal requirements
121.5 MHz 406-406.1 MHz
ELT Fitted into the aircraft with a switch set to ‘armed’ if so marked Automatically on impact N/A 24 hours TSO-C91a or equivalent TSO-C126 or equivalent
EPIRB Portable and carried in a place readily accessible to crew Manual AS/NZS 4280.1:2003 48 hours
PLB AS/NZS 4280.2:2003 24 hours


Back to top