Evaluation of TCAS II Version 7.1 Using the FAA Fast-Time Encounter Generator Model, Volume 1

This report documents the Lincoln Laboratory evaluation of the Traffic Alert and Collision Avoidance System II (TCAS II) logic version 7.1. TCAS II is an airborne collision avoidance system required since 30 passenger seats operating in the U.S. airspace. Version 7.1 was created to correct two potential safety problems in earlier to Vertical Speed Limit or 'Adjust Vertical Speed, Adjust' RAs. Lincoln Laboratory evaluated the logic by examining more than eight million simulated pairwise encounters, derived from actual tracks recorded in U.S. airspace. The main goals of the evaluation were (1) ot study the performance of the revised sense reversal logic for enconuters where one pilot ignores the TCAS advisory, (2) to determine if the revised sense reversal logic has an adverse impact on encounters where both pilos follow the TCAS advisories; (3) to determine if the change from 'Adjust Vertical Speed, Adjust' advisories to 'Level Off, Level Off' advisories provides a safety benefit for TCAS. Three sets of encounters were examined to order to filfull these goals: encounters where both aircraft are TCAS-equipped and both pilots follow the advisories; encounters where both aircraft are TCAS-equipped and one pilot does not follow the advisory; and encounters where only one aircraft is TCAS-equipped. A detailed analysis followed by a summary is provided for each set of encounters. An overall summary is given at the end of the report.

  • Corporate Authors:

    Massachusetts Institute of Technology

    Linclon Laboratory, 244 Wood Street
    Lexington, MA  United States  02420-9180

    Federal Aviation Administration

    800 Independence Avenue, SW
    Washington, DC  United States  20591
  • Authors:
    • Chludzinski, B J
  • Publication Date: 2009-4


  • English

Media Info

  • Media Type: Print
  • Pagination: 100p

Subject/Index Terms

Filing Info

  • Accession Number: 01150560
  • Record Type: Publication
  • Report/Paper Numbers: ATC-346-V1
  • Contract Numbers: DOT-FA8721-05-C-0002
  • Files: TRIS, USDOT
  • Created Date: Feb 9 2010 4:00PM