TCAS II RTCA SC-147

1. TCAS II � RTCA SC-147

2. Overview Recent History October 28 RTCA PMC Meeting Eurocontrol Objectives FAA Objectives Differences in Objectives Proposed SC-147 TOR�s Proposed SC-186 TOR�s Issues Next Steps

3. Recent History Letter from John Law to Nick Sabatini 3/03 Stressed importance of addressing RA reversal logic change resulting from Emotion7 studies FAA agreed to review analyses and discuss new data at May 03 SCRSP meeting Concern that changes to improve SA01 issue may result in adverse effects for other scenarios (FAA Tech Center Analysis) FAA agreed that further analysis was warranted to completely investigate RA reversals RTCA SC-186 pushing to include combined TCAS/ADS-B display issues to be added to SC-186 Terms of Reference

4. Recent History (continued) SCRSP Subgroup meeting September 03 Agreement that SC-147 should be reconvened to address the following issues: Standards for Hybrid Surveillance TCAS/ADS-B Display Integration Agreement on SA01 Issue Investigate changes to Interference Limiting Inequalities Evaluation of Adjust Vertical Speed Adjust Aurals Evaluation of Vertical Speed Tape Action Item to draft letter from SCRSP WG-A to the PMC recommending SC-147 to address these specific issues (Dan & Steve) FAA to draft letter to RTCA PMC to reconvene SC-147 as the appropriate forum of expertise to address issues

5. Recent History (continued) Letter from John Law to RTCA PMC 10/24/03 for SC-147 to address critical safety issues associated with TCAS RA reversal logic and other issues RA Vertical Speed Tape display Aural Alerts (Adjust Vertical Speed-Adjust) Traffic Display Symbology Hybrid Surveillance MOPS FAA expressed support (draft letter) to RTCA for SC-147 to address same issues with slightly different priority

6. PMC Meeting October 28, 2003 PMC Approved Reconvening SC-147 at 10/28/03 meeting with Terms of Reference to be approved on 12/9/03 PMC Resolutions 10/28/03 SC-147 to be reconvened to address specific safety issues with TCAS collision avoidance logic problems described in John Law letter. SA01 Issue/CP112 RA Vertical Speed Tape display Aural Alerts Hybrid Surveillance MOPS (if supported by the majority of manufacturers)

7. PMC Resolutions 10/28/03 (continued) SC-147 would be reconvened as SC-147 after some deliberation about Special Committee designation Bob Buley to act as SC-147 Chair. Terms of Reference to be approved at 12/9/03 PMC meeting after polling of MFG interest in MOPS for Hybrid Surveillance George Ligler to poll TCAS manufacturers for Hybrid Surveillance Support Commitments SC-147 and SC-186 to work together to resolve combined display symbology with SC-186 retaining primary responsibility for the CDTI display in ASSAP/CDTI MOPS.

8. Eurocontrol Objectives SC-147 to address critical safety issues associated with TCAS RA reversal logic SA01 Issue is a critical weakness in TCAS collision avoidance logic which must be corrected to remove a flaw in the RA sense reversal criteria Significantly reduce the risk of TCAS induced NMAC�s RA Vertical Speed Tape display Aural Alerts (Adjust Vertical Speed-Adjust) Traffic Display Symbology Hybrid Surveillance MOPS

9. FAA Objectives Hybrid Surveillance MOPS Manufacturers need standards for Hybrid Surveillance to fuse ADS-B surveillance data into TCAS surveillance logic USAF desires standardization and FAA certification of Hybrid Surveillance for international interoperability of fielded systems SC-147 is the appropriate forum with the required expertise to provide detailed analysis and validation of the SA01 issue If validated, is the appropriate forum to revise DO-185A to reflect changes. 2005 RVSM Rule will introduce higher equipage of TCAS V7 into US airspace which may result in problems identified in European airspace

10. FAA Objectives (continued) If SC-147 reconvened to develop Hybrid Surveillance MOPS Analyze SA01 problem and gain consensus on appropriate resolution Opportunity to Address other issues RA Vertical Speed Tape display Aural Alerts (Adjust Vertical Speed-Adjust) Traffic Display Symbology With SC-186

11. FAA CP112 Issues Activities which must be considered in implementation of CAS logic changes Validation & Verification V&V effort is substantial and independent of the magnitude of changes to the CAS logic. Changes introduced to improve one aspect of the CAS logic, must not introduce negative effects elsewhere. Safety Studies New Airspace Model Address differences in US and European airspace design Time thresholds for RA noncompliance Flight Tests Design of approach geometries Stringent Scope Control

12. FAA CP112 Issues

13. Probabilities by Encounter Class

14. Proposed SC-147 Terms of Reference

15. Proposed SC-186 Terms of Reference

16. Issues Stance of reconvening SC-147 to address �bug-fixes� in TCAS collision avoidance logic Perception of a TCAS flaw Unconfirmed � needs careful analysis and validation by stakeholders FAA Eurocontrol MITRE MIT Lincoln Laboratory Reconciliation of FAA-Eurocontrol Objectives Loss of TCAS expertise since release of DO-185A Budgetary Constraints � Commitment of Resources. Development of DO-185B (CP112) will be a daunting task with several years commitment in analysis and revision of CAS logic

17. Next Steps Identification of resource requirements to accomplish objectives Commitment of resources from stakeholders Identification of Sponsor Funding source and allocation SCRSP WG-A influence on SC-147 Terms of Reference Submittal of Letter from SCRSP/WG-A to RTCA supporting SC-147 Recommendations on Terms of Reference

18. Questions? Any questions??Any questions??