Safety Enhancement 186R3.2 TCAS-Sensitivity Level Command

Safety Enhancement Action: Statement of Work: Total Relation to Current Aviation Community Initiatives: Performance Goal Indicators: Key Milestones: Safety Enhancement 186R3.2 TCAS-Sensitivity Level Command To reduce the rate of unnecessary Traffic Alert and Collision Avoidance System (TCAS) alerts at high altitude airports. Reduce the rate of unnecessary Traffic Alert and Collision Avoidance System (TCAS) alerts at high altitude airports by identifying airports that have high incidents of resolution advisories (RA) triggered by density altitude causing an increased TCAS sensitivity level. Based on site-specific analysis, determine what operational practices or additional guidance will contribute to a reduction in TCAS RAs. SE 165: TCAS Policies and Procedures (Completed) SE 191: New TCAS/Next TCAS Equipment (Underway) SE 188: TCAS ATC Procedures and Airspace Design (Underway) Airborne Collision Avoidance System X (ACAS X) (TCAS Program Office) Determine impact of operational practices or additional guidance, via modeling to verify results by conducting pre- and post-site analysis for TCAS RA s at identified airports. Conduct review of Aviation Safety Action Program (ASAP)/Air Traffic Safety Action Program (ATSAP) data to determine trend(s) after mitigation. Milestone: Support the development of operational practices and/or procedural changes to reduce TCAS RAs and model their effectiveness. Support implementation of changes and monitor their effectiveness. Potential Obstacles: Achieving consensus on proposed changes. Potential negative impact on capacity. Detailed Implementation Plan Notes: CICTT Code: AIRPROX/TCAS Alert/Loss of Separation/Near Midair Collisions (NMAC)/Midair Collisions (MAC) Abrupt Maneuver (AMAN) 2018 04 05 SE 186R3.2 Page 1 of 5

Output 1: Complete a report identifying the necessary infrastructure to change the functionality of Traffic Alert and Collision Avoidance System (TCAS) at high altitude airports. This report should also include the safety impact of the recommended changes. Lead Organization: Federal Aviation Administration (FAA) Air Traffic Organization (ATO) Supporting Organizations: Potential organizations for supplying subject matter experts: FAA Air Traffic Organization (ATO) FAA Office of Accident Investigation and Prevention (AVP) FAA TCAS Program Office MITRE National Aeronautics and Space Administration (NASA) National Association (NACA) Original equipment manufacturers (OEMs) Actions: ATO develops a Work Group Charter to conduct a study. Work Group meets and develops a report of findings. TBD pending choice of action TBD pending choice of action This study will determine feasibility and risk assessment. Time Line: 12 months from CAST approval Target Completion Date: Completed 02/03/2011. Report completed by Lincoln Labs. Output 2: Develop a prioritized list of locations for implementation of infrastructure and functionality changes to Traffic Alert and Collision Avoidance System (TCAS). 2018 04 05 SE 186R3.2 Page 2 of 5

Lead Organization: Federal Aviation Administration (FAA) Air Traffic Organization (ATO) Aerospace Industries Association (AIA) Cargo operators FAA air traffic facility (Denver Terminal Radar Approach Control (TRACON)) National Association (NACA) The Boeing Company Actions: Aviation Safety Information Analysis and Sharing (ASIAS) develops data report of unnecessary TCAS alerts at high altitude airports. ATO reviews the ASIAS data and develops a prioritized list of airports for implementation of TCAS Sensitivity Level Command. Safety Enhancement (SE) focused on Denver International Airport (DEN). Time Line: 12 months from CAST approval Target Completion Date: Completed 12/01/2011. Output 3: Lead Organization: Determine severity of Traffic Alert and Collision Avoidance System (TCAS) Resolution Advisories (RA) at selected sites. Categorize alerts and recommend next steps based on severity determined by analysis. Joint Implementation Measurement and Data Aerospace Industries Association (AIA) 2018 04 05 SE 186R3.2 Page 3 of 5

Cargo operators FAA air traffic facility (Denver TRACON) FAA Air Traffic Organization (ATO) National Association (NACA) The Boeing Company Actions: MITRE will categorize RAs for specified airports and configurations JIMDAT will evaluate results and formulate a recommendation based on severity nuisance alerts may require wide dissemination of advisories, moderate severity may require analysis of operating practices, etc. JIMDAT conducted a detailed analysis to recommend a change based on severity of alerts and offsetting risk. JIMDAT determined in October 2014 that the resources required to implement a technical ground based desensitization solution were unavailable and recommended withdrawal. Time Line: CAST Approval Date: 12/02/2010 Target Completion Date: Withdrawn on 12/04/2014. Output 4 Develop changes in operating practices at Denver International Airport (DEN) to reduce Traffic Alert and Collision Avoidance System (TCAS) Resolution Advisories (RA). These changes should consider altitudes, merge points, distance between aircraft, and the potential operational impact on the traffic flow. Coordinate implementation of these changes with Denver TRACON representatives, other air traffic representatives and operators. 2018 04 05 SE 186R3.2 Page 4 of 5

Lead Organization: FAA Air Traffic Organization Safety and Technical Training (AJI) FAA Air Traffic Organization Mission Support (AJV) FAA air traffic facility (Denver TRACON) FAA Air Traffic Organization Mission Support (AJV) FAA Air Traffic Organization Safety and Technical Training (AJI) MITRE National Air Traffic Controllers Association (NATCA) Joint Implementation Measurement and Data Actions: Through the metroplex process, AJI and AJV will coordinate efforts with the local Denver TRACON representatives, other air traffic representatives and operators to implement a solution. JIMDAT will monitor TCAS RA rates over time to determine effectiveness of solutions Timeline: $50 K (1 Full Time Equivalent for 2 months) TBD based upon selection of mitigation strategy In support of a final balanced solution, the following issues should be considered: Additional air mileage for operators, ATC workload increase, DEN runway throughput impact. Correspond to the DEN Metroplex schedule. Design phase should be complete in 1 year. JIMDAT will monitor progress towards TCAS RA reduction annually Target Completion Date: 12/31/2018 (extended from 04/30/2018). 2018 04 05 SE 186R3.2 Page 5 of 5