Safety Analysis of Upgrading to TCAS Version 7.1 Using the 2008 U.S. Correlated Encounter Model

As a result of monitoring and modeling efforts by Eurocontrol and the FAA, two change proposals have been created to change the TCAS II V7.0 logic. The first, CP-112E, addresses safety issues referred to as SA01 events have to do with the reversal logic contained in the TCAS algorithm, e.g. when TCAS reverses the sense of an RA from climb to descend. Typically, reversals occur to resolve deteriorating conditions during an encounter. V7.0 contained reversal logic based on certain assumptions and engineering judgment, but operational experience obtained since deployment has compelled a re-evaluation in areas of that logic, specifically having to do with late reversals. The second change proposal, CP-115, rectifies observed confusion surrounding the aural annunciation AVSA during an RA by replacing it with the annunciation LOLO, and changing the TCAS V7.0 display and logic to appropirately support the change. Collectively, the changes to the TCAS logic in both CP-112E and CP-115 are referred to as TCAS II V7.1. Including in this document is a safety study that considers V7.1 as a whole, and also the first safety study that uses the U.S. correlated encounter model developed by Lincoln Laboratory for testing TCAS.

• Corporate Authors:

  Massachusetts Institute of Technology

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

  Department of the Air Force

  Pentagon
  Washington, DC  United States  20330

  Federal Aviation Administration

  800 Independence Avenue, SW
  Washington, DC  United States  20591
• Authors:
  • Kuchav, J K
  • Griffith, John Daniel
  • Espindle, L P
• Publication Date: 2009-5

Language

• English

Media Info

• Media Type: Print
• Pagination: 72p

Subject/Index Terms

• TRT Terms: Air traffic control; Aircraft navigational aids; Airspace (Aeronautics); Algorithms; Approach control; Aviation safety; Crash avoidance systems; Simulation
• Subject Areas: Aviation; Operations and Traffic Management; Safety and Human Factors; I85: Safety Devices used in Transport Infrastructure;

Filing Info

• Accession Number: 01138319
• Record Type: Publication
• Report/Paper Numbers: ATC-349
• Contract Numbers: FA8721-05-C-0002
• Files: TRIS, USDOT
• Created Date: Aug 12 2009 12:47PM