This document sets forth minimum operational performance standards for the Airborne Collision Avoidance System Xu (ACAS Xu) equipment, designed for platforms with a wide range of surveillance technologies and performance characteristics, such as Unmanned Aircraft Systems (UAS). Incorporated within these standards are system characteristics that should be of value to users, designers, manufacturers, and installers. These characteristics are intended to accommodate the requirements of various users. This document has to be read together with RTCA DO-365 – “Minimum Operational Performance Standards (MOPS) for Detect and Avoid Systems”