What should pilots follow if a traffic avoidance instruction from ATC conflicts with the TCAS Resolution Advisory (RA)?

Pilots should adhere to the TCAS Resolution Advisory (RA) in the event of a conflict with an air traffic control (ATC) instruction. The TCAS, or Traffic Alert and Collision Avoidance System, is designed specifically to prevent mid-air collisions by providing pilots with immediate guidance on how to safely maneuver their aircraft in relation to nearby traffic.

When a TCAS RA is issued, it carries a higher priority because it is an automatic response to an imminent collision threat, and it is based on the aircraft's real-time data regarding its proximity to other aircraft. Following the RA is essential for ensuring safety, as this system directly addresses the aircraft's immediate operational situation, which might not always be fully known or reflected in ATC instructions.

While ATC instructions are important for managing air traffic flow, the safety-oriented design of TCAS requires pilots to prioritize its advisories, especially during critical phases of flight. In practice, pilots are trained to follow RAs, and if coordination with ATC is necessary after responding to a RA, it is typically done to update them on the situation.