Harmonized Implementation of the ICAO “4 Levels of Threat” System for Managing Unruly Passenger Events

Unruly passenger events continue to increase worldwide, posing risks to flight safety and security. ICAO’s “4 Levels of Threat” system provides a standardized framework to classify and manage these incidents, but inconsistent adoption across States creates operational challenges. IFALPA and IFATCA support harmonized implementation of this system in National Security Programs to improve safety and training consistency.