Issued in September 2008.
Vol I: Minimum Operational Performance Standards for Traffic alert and Collision Avoidance System II (TCAS II) : this document sets forth minimum operational performance standards for Traffic Alert and Collision Avoidance System II (TCAS II) equipment. TCAS II is intended to improve air safety by acting as a last-resort method of preventing mid-air collisions or near collisions between aircraft. By utilizing Secondary Surveillance Radar (SSR) technology, TCAS II equipment operates independently of ground-based aids and air traffic control (ATC).
Vol II: TCAS II Collision Avoidance System (CAS) Requirements Specification : this document contains the Collision Avoidance System Requirements Specification (CRS), a detailed specification of the Collision Avoidance System (CAS) component of the TCAS II system using a precise program specification notation called state charts. It is incorporated by reference into the requirements specification in Volume I. Attachment A to Volume II : this attachment contains an alternate specification of the Collision Avoidance System (CAS) logic in the form of a program in a simplified programming language developed specifically for the purpose. Equivalence between this form of the CAS logic and the state charts has been demonstrated by testing implementations based on each specification against the CAS test suite. However, Attachment A is provided for informational purposes only, and is not formally incorporated into Volume 1 as an alternative statement of requirements.