Airborne Collision Avoidance System (ACAS) guide

This Airborne Collison Avoidance System (ACAS) Guide has been designed to support the understanding of the ACAS systems and the training of people involved in the operations of ACAS.

However, it is not, per se, designed for the complete training of controllers or pilots. For a deeper knowledge, the Reader is advised to refer to documentation listed in the bibliography section.

The Guide concentrates on the ACAS II concept and technical details as well as operation principles of TCAS II version 7.1, as it is the version currently mandated in Europe. The previous TCAS II versions 6.04a and 7.0, as well as TCAS I system, are also briefly described. A preview of the forthcoming ACAS X system is also provided.

The information contained in this Guide, EUROCONTROL ACAS II Bulletins and training presentations is based on the ICAO provisions and other applicable regulations. The information is considered to be accurate at the time of publishing but is subject to change.

This ACAS Guide has been developed by EUROCONTROL with the help of QinetiQ and the German Air Line Pilots’ Association (Vereinigung Cockpit).


Airborne Collision Avoidance System (ACAS) guide - December 2017