Importance of ELT and PLB for flight safety
Emergency Locator Transmitters (ELT) and Personal Locator Beacons (PLB) are essential components of the rescue chain after aviation accidents. They enable search and rescue services to quickly localise an aircraft or crew involved in an accident. Modern systems not only send a distress signal, but also transmit unique identifiers and - depending on the equipment - position data, which significantly speeds up a targeted rescue.
Especially in general aviation, where flights often take place outside controlled airspace or over sparsely populated areas, the reliable functioning of an emergency transmitter can be the difference between life and death. The regulatory requirements for operation, maintenance and documentation are correspondingly high.
Battery replacement for permanently installed ELTs
If an ELT is permanently installed in the aircraft and not designed as a portable PLB, it is legally recognised as an aircraft component. This means that its maintenance is fully subject to the European regulations on continuing airworthiness. These stipulate that maintenance work may only be carried out in accordance with approved procedures, with approved materials and on the basis of approved documentation.
As soon as the battery life specified by the manufacturer has been reached, the ELT must no longer be operated. Battery replacement is mandatory, but only permitted if this is expressly provided for in the approved maintenance documents. As a rule, the component maintenance manual of the ELT manufacturer or the type approval holder is decisive here. It specifies in detail how the replacement is to be carried out and which battery types or battery packs are authorised.
It is important that only the replacement batteries specified in the manual may be used. Even if supposedly compatible or cheaper alternatives are available on the market, these are not permitted without the corresponding approval. The use of unauthorised batteries may impair operational safety and, in case of doubt, invalidate the airworthiness.
As a rule, a component approval certificate is also required for the batteries used. Under aviation law, batteries are regarded as components with a limited service life and are therefore subject to special documentation and monitoring obligations.
Scope and implementation of battery replacement
Depending on the manufacturer and ELT type, battery replacement can go far beyond a simple exchange. In many cases, the maintenance documentation prescribes extensive functional tests, self-tests or fault diagnoses after the replacement. These go beyond a pure function test, such as that carried out as part of a visual inspection.
Certain ELT models must therefore be sent to an authorised specialist company that has the appropriate approval and testing equipment. The device may only be put back into operation once all the prescribed tests have been completed. For owners, this means planning the battery change in good time in order to avoid downtimes of the aircraft.
Use of a PLB as an alternative to the ELT
Under certain conditions, a PLB can be used instead of a permanently installed ELT. This is generally only permitted in non-commercial flight operations and is limited to aircraft that are not considered technically complex. In addition, the maximum permitted number of seats of six persons may not be exceeded.
A key criterion is that the PLB is actually worn on the body - either by a crew member or a passenger. Carrying it loose in the cockpit or baggage compartment is not sufficient. This requirement is intended to ensure that the emergency signal can also be triggered if the crew has to leave the aircraft after an accident. The same applies to so-called survival ELTs, which must also be carried on a personalised basis.
Registration of ELT and PLB
The registration of a permanently installed ELT is carried out as part of the traffic authorisation with the German Federal Aviation Office. Registration solely with international databases is not sufficient for this purpose. Only correct national registration ensures that all relevant information is immediately available in an emergency.
The situation is different for PLBs. These cannot be registered with the Luftfahrt-Bundesamt, but must be registered with the international bodies designated for this purpose. This registration is mandatory so that the identification of the device can be clearly assigned in an emergency.
Up-to-date contact and aircraft data
One aspect that is often underestimated is how up-to-date the stored data is. Contact information, aircraft data and owner details are the basis for efficient alerting and coordination of the emergency services. Outdated or incorrect information leads to delays in an emergency and ties up resources unnecessarily.
Particularly important: The data is not automatically updated when the owner changes. The update must be actively initiated, either as part of the vehicle registration or by a corresponding re-registration. Regular checks of the stored information are therefore strongly recommended.
Minimum technical requirements for frequencies
Modern ELTs and PLBs must be able to transmit simultaneously on the frequencies 121.5 MHz and 406 MHz. Devices that only support one of these frequencies no longer fulfil the current requirements and are not permitted. The frequency equipment of a device can be found in the respective operating manual and should always be checked during purchase, maintenance and operation.
Conclusion
ELTs and PLBs are indispensable safety components in general aviation, the operation of which is subject to clear legal and technical requirements. There are often uncertainties in practice, particularly when it comes to changing batteries in permanently installed ELTs, selecting authorised spare parts and registration. Those who familiarise themselves with the applicable requirements at an early stage, adhere to maintenance intervals and keep the stored data up to date make an important contribution to their own safety and to the efficiency of the international rescue chain.
Source references:
LBA
