1. EUROCONTROL EXPERIMENTAL CENTRE1 AIRSPACE CONGESTION: Pre-Tactical Measures and Operational Events ICRAT Conference, Zilina November 22, 2004 Nabil BELOUARDY PhD Student @ ENST Paris & EUROCONTROL Experimental Centre

2. EUROCONTROL EXPERIMENTAL CENTRE2 Air Traffic Management system  ATS (Air Traffic Service)  Air Traffic Control service  ASM (Airspace Management)  Allocation of airspace  ATFM (Air Traffic Flow Management)  Demand / Capacity balance

3. EUROCONTROL EXPERIMENTAL CENTRE3 Capacity values (ECIP 2004) StateACCCodeHourly movements AustriaViennaLOVV147 EurocontrolMaastricht UACEDYY258 FranceParisLFFF244 FranceMarseillesLFMM210 GermanyMunichEDMM235 GermanyKarlsruhe UACEDUU188 ItalyRomeLIRR186 SlovakiaBratislavaLZBB073 UKLondonEGTT370

4. EUROCONTROL EXPERIMENTAL CENTRE4 Area Control Centre (EGTTC ACC)  Cross section  Opening Scheme EGLMU EGLUS EGLMU EGLMSEG26LME EG25LMW 24:0021:0013:0005:3000:00  Longitudinal section EG01LUWEG02LUE FL 310 EG25LMWUEG26LMEU FL 245 EG25LMWLEG25LMEL FL 195

5. EUROCONTROL EXPERIMENTAL CENTRE5 Flight Plans  Point profile Time: Beacon: Route: FL  1631:EGLL:EGLLBPK6F:000 1634:*1LON:EGLLBPK6F:060 1635:CHT:EGLLBPK6F:060 1638:BPK:M185:060 1640:TOTRI:M185:134 1641:MATCH:M185:147 1643:BRAIN:M185:207 1644:DAGGA:M185:210 1644:*6CLN:M185:210 1645:CLN:L620:210 1647:ARTOV:L620:210 1652:REDFA:EHAMREDFA10:210 1657:SULUT:EHAMREDFA10:175 1700:SUGOL:EHAMREDFA10:100 1705:*SPL:EHAMREDFA10:070 1712:EHAM:EHAMREDFA10:000  Airspace profile min: Airspace: max  1631:EGMIDFI:1631 1631:EGT1ACC:1652 1631:EGTTACC:1652 1631:EILOND:1652 1631:EGTTBNN:1637 1631:EGCCTC2:1646 1637:EGTTLAM:1641 1641:EGTTDAG:1646 1646:EGTTRED:1652 1646:EGCCTC1:1652 1652:EHEB000245:1712 1652:EHM1245:1701 1652:EHSECT4:1700 1656:EHAAFIRT:1712 1700:EHAMTMA:1712 1701:EHACOD:1704  ATFM regulation  Possible delay if flights across some ATC unit exceed capacity.

6. EUROCONTROL EXPERIMENTAL CENTRE6 Need for ATFM regulation  Demand exceeds available capacity in some periods

7. EUROCONTROL EXPERIMENTAL CENTRE7 Computer Assisted Slot Allocation Dynamic and deterministic algorithm:  3 hours before requested take-off time  No change in Flight Plan is possible  Delay affected = Argmax (regulations)  2 hours before take-off  No more delay will be affected  Delay can only decrease  ½ an hour before take-off  Slot is allocated for take-off  Uncertainties  Will the aircraft take its slot ?  Will the crossed sectors be congestion-free? Take-off time  T 0 – 3 h  t 1  T 0 – 2 h  t 2  T 0 – ½ h  t T0T0 t 1 (T 0 – 2 h) t 2 var t 1 var t 2 (T 0 – ½ h)

8. EUROCONTROL EXPERIMENTAL CENTRE8 Efficiency of ATFM regulation  Collapsed sectors (groups) still suffer from over-delivery

9. EUROCONTROL EXPERIMENTAL CENTRE9 Why ? Hypotheses  Uncertainties  If all aircraft take off at its slot, regulation of CASA will be fulfilled  Severe weather  New flight paths result from re-routing  Nonconformity of Capacity with Opening Scheme  No warranty for constraints satisfaction  Aircraft failure to respect Air Traffic rules  Irregularities in traffic shape

10. EUROCONTROL EXPERIMENTAL CENTRE10 Uncertainties ZOOM  Period of 09:00 -13:00  Average uncertainty on EOT is close to zero  Standard deviation is less than 10 minutes  Small center, crossed in almost 10 minutes  Can’t generate130% of capacity (depicted by black color)

11. EUROCONTROL EXPERIMENTAL CENTRE11 Weather  Jet Stream  Physical routes can be shift (traffic variability)  Aircraft coming from America are not concerned Arr Dep United StatesCanada Central America Northern Europe Southern Europeelse United States000300 Canada000000 Central America000000 Northern Europe62058677 Southern Europe000700 else000200 Distribution of aircraft that have eerie flight plans according to Departure and Arrival areas

12. EUROCONTROL EXPERIMENTAL CENTRE12 ACC Capacity vs. Opening Scheme Traffic load in opened groups (Filed configuration)  Bad from 13:00 to 21:00  Actual configuration ?

13. EUROCONTROL EXPERIMENTAL CENTRE13 ACC Capacity vs. Opening Scheme  Final demand and Regulated traffic curves are almost identical, no obvious limitation  Flight demands comply with ACC capacity constraints  At collapsed sector level, capacity of activated groups are exceeded  Regulation at a Macro level (Centre) does not insure a safe flow at micro level (Opening scheme)  Trade-Off: Over-flow / Delay  Adaptive optimization of Opening Scheme to the observed traffic  Control of used ACC capacity value to prevent the congestion in groups

14. EUROCONTROL EXPERIMENTAL CENTRE14 Stochastic pre-tactical planning Other traffic shapes of other sub-centers of London EGTT shows  Compliance between Final demand and Regulated traffic  No excessive demand  Compliance between Regulated and Current traffic  Smoothed uncertainty No need for stochastic

15. EUROCONTROL EXPERIMENTAL CENTRE15  Over-delivery / Total delay trade-off  Consistency problem between Macro / Micro layers  Will be investigated  Possible if demand grows as fast as airspace resource improvement  If demand continue increasing while capacity remains steady  Regulation by ATFM delay will reach saturation  Less aircraft are to be controlled if Long range flights are isolated in a kind of uncontrolled highways (like over the oceans) Conclusion

16. EUROCONTROL EXPERIMENTAL CENTRE16 THE END Thank you for your attention Questions ?