ATFM Priorities Evaluation Study Alison Hudgell QinetiQ Presentation to EUROCONTROL/FAA Action Plan 6 TIM 8 “Collaborative Decision Making Applications in Air Traffic Flow Management” ATFM Priorities Evaluation Study Alison Hudgell QinetiQ

Background “ATFM Priority Options” Study (1998) for European Commission how to reduce operational impact of congestion considered chronic congestion and “crises” stakeholder interviews proposed prioritisation strategy options EUROCONTROL commissioned to validate proposals through simulation ATFM Priorities Evaluation Study (2000-1) Chronic congestion - saturation of ATC capacity on a repetitive basis, over an extended period of time Crisis - big difference between available capacity and traffic demand, over short period. Could be: - reduction in capacity - increase in demand Current rule is First Planned, First Served (as we have probably heard) Proposing alternative strategies, with the aim of reducing operational impact.

Agenda Project Background Assessment criteria Proposed ATFM strategies description assessment recommended next steps Conclusion

Assessment Criteria Feasibility of technical implementation Potential abuses & feasibility of verification Implementation acceptability to stakeholders Frequency or range of applicability Benefits: delay reduction and split amongst target population Impact on ATFM performance July 2000 traffic used, some Saturdays, some weekdays

Overview of Strategies “Global” Solutions - Slot Allocation Prioritised by: Flight Type Least Consumer Cost Flight Distance CDM Procedures for Prioritisation of Particular Flights Integration of AO Tactical Priorities Selective Amelioration Airport Public Order Exceptions Burden Sharing Public Comment Proceedings …will explain each in turn, with assessment conclusions

Global Prioritisation Strategies Current: First Planned First Served all flights are equal Proposed: Prioritisation by ... Flight Type - some types more time-critical Consumer Cost - equity per passenger Flight Distance - equity over day’s operation Modified slot allocation algorithm to prioritise flights by category Redistribute delays across flight categories Least Consumer Cost really done per seat (easier to assess). Could also include freight, by weight, in a model of “consumer cost”. Flight Distance short-haul flights make several sectors in a day - delay on each sector adds up. These are alternatives - different views of equity. Intend to apply one or another, not in combination! Possibly different models might be appropriate at different times/regulations Different implementations tried - full prioritisation (allocate all 1st category flights first, then next category, …) - partial prioritisation (weighted function using ETO and rank) - different weights

Global Prioritisation Strategies (2) Flight Type  rejected 75% of regulated flights in high-priority class prioritisation ineffective problems of verification / policing Least Consumer Cost  rejected categorisation / validation more feasible redistributes delay from larger to smaller aircraft negative impact on hub operations Flight Type Least Consumer Cost categorisation easier to tune (70% has 100 seats+; 100-200 seats = 50%; 4-100 seats = 20-25%) aircraft size easier to verify but - pax number more difficult; - what about freight? Negative impact on hub operations - smaller flights delayed more = feeder flights, => knock-on delays to long-haul flts

Flight Distance Results Recommended next steps equal-sized categories most effective “strength” of prioritisation can be tuned with 5 equal categories; weight: 20% to prioritisation / 80% to FPFS improved hub management Recommended next steps stakeholder consultation/analysis concerning strength of prioritisation dynamic slot allocation algorithm flight duration is verifiable “equal-sized categories” => categories with equal populations of flights - but traffic distribution varies with day/time and location (more work needed to develop best approach - good average classification to avoid flight being treated differently on dfferent days?) strength of prio can be tuned by adjusting relative weight given to FPFS order and ranking in slot allocation algorithm

Overview of Strategies “Global” Solutions - Slot Allocation Prioritised by: Flight Type Least Consumer Cost Flight Distance CDM Procedures for Prioritisation of Particular Flights Integration of AO Tactical Priorities Selective Amelioration Airport Public Order Exceptions Burden Sharing Public Comment Proceedings

Integration of AO Tactical Priorities “Slot Swapping” and “Substitution on Cancellation” AO to decide on swaps between flights limitiation: same regulations in same order Modelled Operational Implementation swap flights only of same AO minimum improvement: 5 minutes SIT1A < CTOTB - taxi time - margin for swap 50% of CFMU flights pass through more than one regulation How many cases? What impact on ATFM? -> simualtion to find out

Estimate Number of Slot Swaps 1 in 3 “feasible” swaps is required (random selection) Each flight may swap only once (random selection)

Slot Swapping - Conclusions Estimate 100 - 200 swaps per day daily delay savings on critical flights of 1600 to 4000 minutes No disbenefit to non-swapping operators No systematic impact on bunching or overload Recommended next steps define procedure and rules trial implementation More opportunities on crisis days Flag carriers at each of Europe ’s most congested hubs (not surprisingly) get largest number of potential swaps No dis-benefit to other operators Daily delay saving: - 1600 to 2400 mins on «normal» days, - over 4000mins on 7/7/00=crisis day At 25euro/min (IATA figure) => - 40,000 to 60,000 euro on normal days - in excess of 100,000 euro in crisis case

Overview of Strategies “Global” Solutions - Slot Allocation Prioritised by: Flight Type Least Consumer Cost Flight Distance CDM Procedures for Prioritisation of Particular Flights Integration of AO Tactical Priorities Selective Amelioration Airport Public Order Exceptions Burden Sharing Public Comment Proceedings

Selective Amelioration AOs request amelioration of delayed flights that have become critical - e.g. airport curfew air-crew rostering transfer passengers Ad-hoc process exists today Need to limit number of cases agreed constraints? quota system Selective Amelioration of Serious, Unplanned Constraints e.g. of constraints: - destination airport curfew - air crew roster - aircraft turnaround problems (e.g. flight technical) - significant number of transfer pax - just-in-time freight operations FPFS does not recognise criticality Biggest concern with this is impact on ATFM performance! Fairly obvious benefit to Airlines! Hence need to limit number of cases.

Selective Amelioration (2) Modelled random selection among flights delayed by more than 30 minutes Biggest concern with this is impact on ATFM performance! Graph suggests that maybe 200 flights / day could be ameliorated without significant adverse effect on ATFM performance BUT significant differences between days and between scenarios, and need to check result in dynamic implementation Modelled selective amelioration: - by forcing through at requested time - of a random selection of flights delayed by >30min - random samples making 0.5% to 5% of regulated demand - required delays between 0 and 20min (random choice)

Selective Amelioration - Conclusions Minimal impact on ATFM performance from amelioration of up to 200 or so flights? further validation needed Recommend limiting number of cases by quota system Recommended next steps monitor and analyse current live usage stakeholder consultation on how to distribute quota across AOs trial implementation 200 flights is about 1% of demand. Quota system means that AOs will only use this facility for their most critical flights

Overview of Strategies “Global” Solutions - Slot Allocation Prioritised by: Flight Type Least Consumer Cost Flight Distance CDM Procedures for Prioritisation of Particular Flights Integration of AO Tactical Priorities Selective Amelioration Airport Public Order Exceptions Burden Sharing Public Comment Proceedings

Airport Public Order Exceptions Initial aim: when serious delays lead to risk of public order disturbances Delegation of control from central (CFMU) to local (Airport) level e.g. now: De-Icing Procedures generalise: “Chaotic Situation Management” If number of flights affected is small, use Selective Amelioration Initial aim: when serious delays lead to risk of public order disturbances - but can be used more generally for any case when local crisis (weather, fire, …) means prioritisation is more appropriately decided and applied locally = Chaotic Situation Management Decision-making delegated to a local problem manager who has best view of local situation No simulations. Returning to public order issue - if few flights affected...

Airport Public Order Exceptions (Chaotic Situation Management) Monitoring and reporting of use to guard against abuse or overuse Recommended next steps trial implementations put in place Letters of Agreement Abuse might amount to prioritisation of local airline’s flights by local authority Bi-lateral letters of agreement are the existing mechanism for De-Icing procedures

Overview of Strategies “Global” Solutions - Slot Allocation Prioritised by: Flight Type Least Consumer Cost Flight Distance CDM Procedures for Prioritisation of Particular Flights Integration of AO Tactical Priorities Selective Amelioration Airport Public Order Exceptions Burden Sharing Public Comment Proceedings

Burden Sharing Applicable when capacity shortfall expected to avoid delays, must reduce demand all make agreed proportional reduction AOs to decide which specific flights to cancel Currently, national ad-hoc frameworks for crisis management Strategic or Pre-tactical procedure Some current examples, but use not systematic

Burden Sharing Trade-off of demand cut and delay saved Simulations: implemented AO demand reduction model applied regulations to reduce capacity (Demand reduction model = random!) Results averaged over several scenarios - example regulations - days’ traffic Significant differences between scenarios

Burden Sharing - Conclusions Implement as fully structured collaborative process strategic or pre-tactical Recommended next steps refine guidelines for demand reduction - especially among smaller operators develop collaborative procedures apply in trial cases

Overview of Strategies “Global” Solutions - Slot Allocation Prioritised by: Flight Type Least Consumer Cost Flight Distance CDM Procedures for Prioritisation of Particular Flights Integration of AO Tactical Priorities Selective Amelioration Airport Public Order Exceptions Burden Sharing Public Comment Proceedings

Public Comment Proceedings Strategic planning to deal with large events capacity enhancement demand management and prioritisation Transparent, consensus-based planning EAG-OSG level Recommended next steps analysis of events to date consultation on guidelines for applicable events trial procedures in real cases Scheduling for major events can be extremely time-sensitive - FPFS can lead to unacceptable degree of disorder. Strategic agreement/identification of high priority flights - e.g. ensure key personalities not late for opening ceremony! Again - exists now in ad-hoc form, but need “proceduralising” - systematic use! Strategic plans may enable local prioritisation under Chaotic Situation Procedures

Conclusion All strategies apply to crises, several also to chronic congestion None appear to reduce ATFM performance Many formalise existing procedures Some could provide incentives for “good behaviour” by AOs Recommended next step for many is specification of procedures and live trial Institutional and operational issues remain to be addressed In a crisis, makes sense to do what you can to reduce impact on operations - but need to have agreed approaches and procedures to ensure they can be successfully applied Further development of these is subject to - stakeholder agreement - competing priorities for developments of CFMU / ATFM !!