Operational monitoring and modelling of Airborne and Ground-based Safety Nets performance 22-24 October 2008 Thierry Arino, Christian Aveneau, Stanislaw Drozdowski & Béatrice Raynaud Email: safety-nets@eurocontrol.int Safety R&D Seminar, Southampton, 22-24 October 2008
Background & context Ground-based & airborne safety nets (STCA & ACAS) Two systems of different maturity and scope, developed independently from each other STCA standardisation is under progress in Europe STCA is mandatory for end of 2008 STCA is deployed in several States with a wide range of implementations ACAS standards are defined at ICAO level since 1997 ACAS II mandatory carriage exists worldwide There is a single ACAS compliant equipment Safety R&D Seminar, Southampton, 22-24 October 2008 2
History 1997 1999 2001 2003 2005 2007 2009 2011 O ACAS formance riented ARPs ACASA project (European ACAS mandate) IAPA project (ACAS vs. ATM modification) ASARP project (ACAS vs. RVSM) I-AM-SAFE feasibility study PASS project (STCA performance) EMOTION-7 project (TCAS monitoring) SIRE initiative (TCAS safety improvement) Safety R&D Seminar, Southampton, 22-24 October 2008 3
PASS monitoring activity (Phase 1) Contribute to a better knowledge and understanding of the current operational situation Collection and analysis of relevant STCA and ACAS occurrences in Europe Data provision by DSNA, Skyguide and DFS Radar Surveillance & RA downlink Airborne recordings Air Safety Reports (by pilots) Mode S Ground Station Approach & ACC units ATC recording (radar situatio STCA alerts, R downlink, etc ATCO incident reports Safety R&D Seminar, Southampton, 22-24 October 2008 4
Initial monitoring results (1/2) Ongoing qualitative & quantitative analysis of the sequence of STCA & ACAS related events ATC2 STCA 1 STCA 2 AC1+TCAS AC2+TCAS STCA (1) STCA (2) LOS ATC2 AC2 climb again TA TA CPP RA RA 1000ft AC1: «TCAS descent» CPA CoC Hdist (NM) 15 8 6.20 5.6 5 4 3.8 1.8 1.1 0.95 Vdist (ft) 1500 1000 900 850 800 700 700 750 1000 1700 Hrate (NM/mn) 14 13.4 13 13.5 13.5 13.4 13.3 11.7 7.8 Vrate (ft/mn) 1100 975 900 1100 1100 1100 1100-3000 -5400 56:20 56:48 56:56 56:59 57:02 57:06 57:08 57:16 57:20 57:21 57:23 57:28 Safety R&D Seminar, Southampton, 22-24 October 2008 5
Initial monitoring results (2/2) Statistical analysis of SNETrelated occurrences Number of aircraft (No urgency in light color) Timing and nature of events (STCA alert, controller s reaction, pilot s response, TCAS RAs, etc) 35 30 25 20 15 10 5 0 simultaneous 1-5 s 6-10 s 11-15 s 16-20 s 21-25 s 26-30 s 31-35 s 36-40 s 41-45 s 46-50 s Position of aircraft manoeuvre compared to avoiding action time > 50 s Specific analysis of TCAS occurrences based on RA downlin Nearly 900 encounters with valid recorded RAs Mode A/C threat 29% Unknow n threat Other 5% 1% Mode S threat 17% TCAS threat in TA-only 2% TCAS threat with cordinated RA 17% TCAS threa w ithout RA 29% Safety R&D Seminar, Southampton, 22-24 October 2008 6
Setting-up the model-based performance evaluation Enhanced simulation framework building on the results of the I-AM-SAFE feasibility study and the PASS monitoring activity Encounter model for Safety-net related occurrences Controller response model ATC surveillance model STCA simulations Pilot response model Altimetry error model ACAS simulations Underlying level of safety (without STCA nor ACAS) Level of safety achieved with STCA Overall level of safety with ACAS Safety nets contribution Safety R&D Seminar, Southampton, 22-24 October 2008 7
Next steps of the PASS study (Phases 2 & 3) Develop quantified performance and safety requirements for STCA alerts Safety encounter model STCA performance metrics (e.g. warning times) Level of STCA / ACAS interaction 100000 80000 60000 40000 20000 0 50s 80s 90s <0 <20 <40 <60 <80 <100 <120 <140 <160 <180 seconds TMA NoCFL L TMA NoCFL H EnRte CFL Lo EnRte CFL H Provide core elements for a consistent overall concept for STCA and ACAS operations Operational requirements and recommended ATCO working method Safety R&D Seminar, Southampton, 22-24 October 2008 8
Conclusions Ongoing operational monitoring of airborne and groundbased safety-net related occurrences will provide a better understanding of the current situation Encounter model-based methodology demonstrated to be applicable and useful to evaluate STCA performances and level of STCA / TCAS interaction Future modelling of airborne and ground-based safety nets performance to be complemented with specific Human Factors and Safety assessment methodologies Foundation for safe and efficient STCA and ACAS joint operations (end 2010 / early 2011) Safety R&D Seminar, Southampton, 22-24 October 2008 9