Document Scope and Objectives

ICAO Annex 6 requirements and the associated ICAO Global Aeronautical Distress and Safety System (GADSS) Concept of Operations (ConOps) describe a set of capabilities to enhance locating a downed aircraft or an aircraft in distress. These capabilities cover aircraft tracking during routine operations (normal tracking), distress tracking, and improved aircraft crash site localization. This includes longer operational life underwater beacons, low frequency underwater beacons, and the timely recovery of flight data.

The scope of this report is to document the system-level requirements for an Autonomous Distress Tracking (ADT) System, provide a survey of potential architectures to support these requirements and to present proposed interface standards for these architectures to support improved interoperability and interchangeability. The broader ICAO Annex 6 and GADSS ConOps scope and the focused scope of this study are shown in Figure 1.

Purpose of this Document

This document describes the technical requirements, architectural options, and recommended interface standards to support an Autonomous Distress Tracking (ADT) System intended to meet global regulatory requirements for locating aircraft in distress situations and after an accident. This document is prepared in response to International Civil Aviation Organization (ICAO) and individual Civil Aviation Authorities (CAAs) initiatives.

COMMENTARY

The difficulty in locating the crash sites of several commercial aircraft over the last decade has prompted significant international effort to establish global aircraft tracking capabilities for commercial aircraft. Since 2015, ICAO has updated ICAO Annex 6 Standards and Recommended Practices (SARPs) to include requirements for tracking commercial planes during all phases of flight, including functionality for autonomous identification and reporting of distress situations using Autonomous Distress Tracking (ADT). In addition, the European Commission has published Commission Regulation (EU) 2015/2338 with similar, but in some cases differing requirements.

The ICAO and CAA requirements cover both aircraft-level considerations and ground system considerations. This report also documents additional system-level requirements derived from the evaluation of ICAO, CAA, and relevant industry documents. It describes candidate ADT system architectures.

Multiple potential ADT architectures are described, in the context of a common architectural framework and requirements identified in this report, covering the primary proposed system candidates. Implementation recommendations and recommended interface standards from an aircraft perspective are also discussed.