The GADSS concept of operations is to provide autonomous global, end-to-end tracking of commercial flights so that an aircraft is never “lost.” It focuses on the detection of aircraft in distress anywhere in the world. It supports accurate tracking throughout the flight so the search and rescue (SAR) procedure can be initiated, if required, and rescuers directed to the correct location. This process enables more efficient SAR operations as well as timely retrieval of the flight data recorder (FDR).

To make aircraft flight safer, ICAO has identified tracking components and technologies for three operation phases:

• Aircraft tracking (AT) during normal operations – The aircraft position information needs to be updated and available to the airline operations center (AOC) and air traffic services (ATS) and provide:
  • 100% global coverage
  • Automated 4D 15-minute tracking
  • Two-way link between GADSS system and the AOC
• Autonomous distress tracking (ADT) during abnormal operations – The aircraft position information needs to be updated and additionally provide:
  • Independent detection of aircraft in distress
  • Autonomous activation of one-minute reporting when an aircraft is in a distress condition, without the need for flight crew action
  • Automated 3D one-minute tracking
  • Resilience to loss of aircraft power, communication and navigation systems
• Post-flight localization and recovery – Accurate aircraft position information to locate aircraft within 6 NM of termination.

The aircraft tracking function under normal operations was applicable on November 8, 2018.

As of January 1, 2021, all three standards of GADSS will apply to all new-built aircraft with take-off weight greater than 27,000 kg. Other new aircraft with take-off weight greater than 5,700 kg are also recommended to comply with the GADSS requirement from the same date.