Description

The EUROCONTROL Safety Improvement Sub-Group (SISG) identified TCAS RA Not Followed as one of the Top 5 ATM Operational Safety Priorities in 2017.

There was no reliable and representative data on the number of TCAS RA not followed. The results from different sources ranged from 1% to 35%. Therefore, a survey on the matter among pilots was conducted. It was voluntary and received 3800 responses from 90 countries.

The aim of the survey was to gather and analyze statistical data to better understand the factors that lead to TCAS RA non-compliance and the impact of the operational environment on such occurrences.

The time period covered by the survey was 5 years ending in 2017.

A dedicated study combined the results of the survey with theoretical analysis of relevant generic scenarios and possible safety barriers.