Doc 10150, Manual on the Functional Specifications for the Location of an Aircraft in Distress Repository (LADR). First edition, 2021.
The purpose of the functional specifications for the Location of an Aircraft in Distress Repository (LADR) is to define the requirements for a centralized repository of location information resulting from activations of aircraft distress tracking systems. The Repository enables operators to meet the requirements of Annex 6 — Operation of Aircraft, Part I — International Commercial Air Transport — Aeroplanes, Chapter 6, 6.18.3 to make position information of a flight in distress available to appropriate organizations, as established by the State of the Operator, while also meeting the expectation from the search and rescue (SAR) community that such information will be held in a single place such that information from different autonomous distress tracking (ADT) systems would be collected together, thereby facilitating quick access to the last known position of the aircraft.
On 2 March 2016, the ICAO Council adopted Amendment 40-A to Annex 6 — Operation of Aircraft, Part I — International Commercial Air Transport — Aeroplanes, which included, among other elements, Standards and Recommended Practices (SARPs) related to the location of an aeroplane in distress (Chapter 6, 6.1.8, refers). These SARPs address the Global Aeronautical Distress Safety System (GADSS) autonomous distress tracking (ADT) concept and became effective on 11 July 2016, with an applicability date of 1 January 2021. Amendment 40-A was issued in July 2016.
The SARPs are applicable to aeroplanes with a take-off mass greater than 27 000 kg for which the certificate of airworthiness is first issued as of 1 January 2021, and establish the requirement to autonomously transmit information from which a position can be determined by the operator at least once every minute when in a distress condition. The same is recommended for new aeroplanes for which the certificate of airworthiness is first issued as of 1 January 2021 with a take-off mass greater than 5 700 kg. An aircraft is considered in distress when it is in a state that can, if the behaviour event is left uncorrected, result in an accident.
The SARPs state that the autonomous transmission of position information needs to be active when an aircraft is in a distress condition. This will provide a high probability of locating an accident site to within a 6 NM radius. Annex 6, Part I, Appendix 9, also specifies that this transmission can be activated manually. Annex 6 is not technology-specific and will allow for various solutions, including triggered transmission systems. The autonomous transmission of position information needs to be capable of occurring in the event of aircraft electrical power loss, at least for the expected duration of the entire flight. For further details regarding the requirements for an ADT system, refer to the Manual on Location of Aircraft in Distress and Flight Recorder Data Recovery (Doc 10054).
The SARPs also establish the requirement for making this information available to authorities such as: rescue coordination centres (RCCs); air traffic services units (ATSUs); and others as determined by the State of the Operator.
Performance-based standards for ADT systems allow the industry develop different degrees of innovation. The challenge, however, is to make the ADT position information available in a standard format for the primary intended audience, the RCCs and ATSUs. To accomplish this, the Global Aeronautical Distress and Safety System (GADSS) concept of operations (CONOPS) identified the need to store and provide access to ADT position information by means of a centrally managed repository, originally referred to as the Distress Tracking Data Repository and now referred to as the LADR, and implemented in accordance with the guidelines provided in the Manual on System Wide Information Management (SWIM) Concept (Doc 10039).
Additional provisions have been drafted for the Procedures for Air Navigation Services — Aircraft Operations, Volume III — Aircraft Operating Procedures (PANS-OPS, Doc 8168) which will require that the information related to the position of an aircraft in distress be provided to the centrally managed repository.