So far you have confirmed that your distress beacon will be used as an aviation Emergency Locator Transmitter (ELT) and that it is a non-location protocol beacon. Four coding options have been developed for this type of beacon. However, your selection should be restricted to those protocols that have been authorised by your country’s competent authority on distress beacon matters (additional information concerning the authority/responsibility of States in respect of beacon message protocol selection is described at step 1 of this tutorial). From the protocols approved for use by your country’s designated authority on distress beacon matters, the option to be selected depends on the information that you would like programmed into the beacon and its intended use. To proceed select the option that best suits your needs.
Serial User Protocol Coded with a Unique Beacon Serial Number: This option uses a serial number, allocated by either the competent national authority or the beacon manufacturer, to uniquely identify the beacon. A feature of this protocol is that it does not include information which directly identifies the aircraft in which it is installed, consequently, the ELT can be moved to another aircraft without necessarily requiring recoding. When this protocol is used, SAR services are 100% dependent upon beacon registration for obtaining any information concerning the aircraft or the operator of the beacon. Therefore, it is essential to ensure that the beacon is properly registered and that registration information is updated if the registration information changes or the beacon is moved to a different aircraft.
Serial User Protocol Coded with the Aircraft Operator Designator & a Serial Number: This protocol was designed for use by operators of fleet(s) of aircraft (e.g. airlines). This option uniquely identifies the beacon using a combination of :
- an aircraft operator designator code defined in accordance with International Civil Aviation Organization (ICAO) DOC 8585, accompanied by
- a serial number between 1 and 4096 assigned by the operator.
Since the beacon code identifies the operator, subject to national regulations, the operator will be able to change ELTs amongst its fleet, provided that the operator establishes a 24-hour point of contact available to SAR services for informing SAR personnel of which ELT is on which aircraft.
Serial User Protocol Coded with the Aircraft 24-Bit Address: This option uses the unique 24-bit binary aircraft identification code assigned by National Administrations to encode the beacon identification. The format for the 24-bit code is described in Annex 10 to the Convention on International Civil Aviation. This code can only be used if your country assigns a 24-bit designator to your aircraft.
Aviation User Protocol Coded with the Aircraft Nationality and Registration Marking: This option uses the unique alphanumeric aircraft registration marking assigned by National Administrations to code the beacon identification. The format for this designator is provided in Annex 10 to the Convention on International Civil Aviation.
Note: The Convention on International Civil Aviation requires all 406 MHz ELTs to be registered with the appropriate national authorities.