Introduction to TCAS II

Introduction to TCAS II - Version 7.1

This booklet provides the background for a better understanding of the Traffic Alert and Collision Avoidance System (TCAS II) by personnel involved in the implementation and operation of TCAS II.
This booklet is an update of the TCAS II Version 7.0 manual published in 2000 by the Federal Aviation Administration (FAA). It describes changes to the CAS logic introduced by Version 7.1 and updates the information on requirements for use of TCAS II and operational experience.

Version 7.1 logic changes will improve TCAS Resolution Advisory (RA) sense reversal logic in vertical chase situations. In addition all “Adjust Vertical Speed, Adjust” RAs are converted to “Level-Off, Level-Off” RAs to make it more clear that a reduction in vertical rate is required.

The Minimum Operational Performance Standards (MOPS) for TCAS II Version 7.1 were approved in June 2008 and Version 7.1 units are expected to be operating by 2010-2011. Version 6.04a and 7.0 units are also expected to continue operating for the foreseeable future where authorized.

Some Titles:

RVSM Considerations
TCAS II Components
TCAS Computer Unit
Mode S Transponder
Traffic Display Symbology
Mode S Surveillance
Collision Avoidance Concepts