From 1 February 2009, all ELTs must operate on frequencies 406 and 121.5 MHz.
ELTs which operate solely on 121.5 and 243 MHz are now obsolete.
Background
The Civil Aviation Regulations 1988 (CAR) require the carriage of an emergency locator transmitter (ELT) on most flights in Australian airspace. ELTs are distress beacons which are activated following an accident either automatically by embedded electronics, or manually by a pilot or other person. An active beacon is detected by orbiting satellites which transmit a signal to search and rescue coordinators. An internationally utilised service provider ‘Cospas-Sarsat’ is currently used in Australia to provide satellite-based ELT monitoring services. The ELT also emits a transmission on a frequency which can be detected, and homed in on, by overflying aircraft.
The Cospas-Sarsat system ceased processing the 121.5/243 MHz signals from distress beacons on 31 January 2009. The system now only detects 406 MHz beacons.
Cospas-Sarsat made the decision to cease satellite processing at 121.5 MHz 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 121.5 MHz beacons and the superior capabilities of the 406 MHz alerting system where the position of the distress can be relayed to rescue services more quickly, more reliably and with greater accuracy if coupled with GPS position data. While the 406 MHz transmission is essential for satellite monitoring, a 121.5 MHz component of the transmission is still necessary to assist with the final homing of an activated beacon.
The new rules
The updated rules in Civil Aviation Regulation 1988 (CAR) 252A require all aircraft which required the carriage of an ELT before the 1 February 2009 “switchover” date, to carry an ELT which operates on frequencies 406 and 121.5 MHz.
Provision for the use of 406/121.5 MHz portable emergency personal indicating radio beacons (EPIRBs) and personal locator beacons (PLBs) also remains in the new CAR 252A.
A new requirement is that the 406/121.5 MHz ELT must be registered with the Australian Maritime Safety Authority (AMSA). This is crucial for the proper operation of the ELT, and is a free service. More information about the registration process is available on the AMSA website or by calling (freecall) 1800 406 406.
A Notice of Final Rule Making (NFRM) details the rule changes which became effective on 1 February 2009.
Additional information
406 Beacon information
