ABCD: Aircraft Based Concept Developments

Transcription

1 ABCD: Aircraft Based Concept WORK PACKAGE 8 DELIVERABLE D8 Simulation methodology and scenarios definition for the unused ATFM slots analysis This document presents a synthesis of information aiming to support discussions concerning ABCD concept and processes. It does not represent the position of Agency. 1

2 Page: 2 DOCUMENT IDENTIFICATION SHEET DOCUMENT DESCRIPTION Document Title ABCD: Aircraft Based Concept Deliverable D8: Scenarios and simulations methodology definition for the unused ATFM slots analysis Abstract This document presents the selected scenarios and proposed methodology for the execution of the simulations to be run to perform the analysis of the impact of delay messages anticipation on unused ATFM slots. Keywords CFMU Airport ATC ATFM Capacity Airlines Coordination CTOT Delay EOBT FPL Messages Unused Slots Anticipation Regulation TACOT simulation CONTACT PERSON: TEL: DIVISION: DOCUMENT STATUS AND TYPE STATUS CATEGORY CLASSIFICATION Working Draft Executive Task General Public Draft Specialist Task EATMP Proposed Issue Lower Layer Task Restricted Released Issue INTERNAL REFERENCE NAME: ELECTRONIC BACKUP HOST SYSTEM MEDIA SOFTWARE Microsoft Windows Type: Media Identification: 2

3 Page: 3 DOCUMENT CHANGE RECORD The following table records the complete history of the successive editions of the present document. EDITION DATE DESCRIPTION OF EVOLUTION SECTIONS / PAGES AFFECTED /05/2008 Working Draft Creation All /07/2008 Updated after consolidation of requirements with the TACOT facility managers 3

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5 Page: 5 SUMMARY The present document, Deliverable D8, presents the results for Work Package 8 Simulation definition for the unused ATFM slots study, as part of the ABCD project. The proposed Unused ATFM slots analysis intends to prove that the earlier the notification of delay messages to the CFMU, the lower the number of unused ATFM slots and the lower the ATFM delay. Consequently, it would demonstrate that improving delay messages anticipation is beneficial to everybody, airspace users, as well as network management. In that sense, it would point to the virtues induced at central level by the local use of a distributed system like ABCD. To prove these assumptions, fast-time ATFM simulations using TACOT platform will be performed. The effect of the anticipation of delay messages on the number of unused slots and on the ATFM delay will be simulated on real traffic. For this purpose a comparative assessment will be performed between the baseline situation and several alternative situations where the anticipation of the delay messages is increased by a specific amount of time. The traffic sample to be simulated is selected from the CFMU data warehouse for 2007.The six most suitable days of the year for the purpose of the simulations are chosen, that is those with high ATFM delay, high number of regulated flights, high number of regulated flights that sent delay messages and supposedly high number or unused slots. The proposed selection of days corresponds to the following dates: 14/06/07, 15/07/07, 21/06/07, 22/06/07, 30/06/07 and 20/07/07. A baseline scenario and a set of 7 alternative anticipation scenarios are defined to be executed by the TACOT platform. Simulations will be run in two cycles. The first simulation cycle aims to calibrate the simulation platform, validate the simulation specifications (simulation, methodology, inputs, required outputs ) and confirm the selection of the traffic sample and the configuration of scenarios. For these purposes, the first simulation cycle will run for two days of the traffic sample (21 and 22 of June 2007) the complete set of proposed scenarios: baseline and alternative scenarios. First simulation results for these days will be assessed in order to validate the first simulation cycle or to propose refinements if needed. Once the first cycle is stable and validated, the second simulation cycle will start running for the rest of the days the complete set of confirmed scenarios. First cycle of simulations is scheduled to run for 4 weeks time, 2 weeks for the baseline scenario preparation and execution and 2 more weeks for the alternative scenarios. Second simulation cycle will last for 2-4 weeks depending on cycle 1 results and evolution of the entire simulation process. All decisions and assumptions presented in this document have been settled in cooperation with the TACOT facility managers. 5

6 Page: 6 TABLE OF CONTENTS SUMMARY INTRODUCTION ABCD OVERVIEW PROJECT BACKGROUND PROJECT PURPOSES AND SCOPE PURPOSE OF THE DOCUMENT STRUCTURE OF THE DOCUMENT PRINCIPLES OF THE UNUSED ATFM SLOTS SIMULATIONS UNUSED ATFM SLOTS BACKGROUND OBJECTIVES OF THE UNUSED ATFM SLOTS SIMULATIONS SIMULATION METHODOLOGY DEFINITION OF SCENARIOS TRAFFIC SAMPLE Traffic Scope Selected days Justification of the selection BASELINE SCENARIO Scenario design Required outputs Scenario execution ALTERNATIVE ANTICIPATION SCENARIOS Scenarios design Required outputs Scenarios execution SIMULATIONS EXECUTION PROCEDURE AND SCHEDULE EXPECTED RESULTS AND FURTHER ANALYSIS CONCLUSIONS AND NEXT STEPS CONCLUSIONS NEXT STEPS DICTIONARY OF ABBREVIATIONS REFERENCE DOCUMENTS ANNEX 1 ATFCM TECHNICAL OVERVIEW ANNEX 2 OPERATIONAL DATA FOR THE UNUSED SLOTS ANALYSIS

7 Page: 7 TABLE OF FIGURES Figure 1: Delay message anticipation concept Figure 2: ABCD simulation methodology Figure 3: ATFM delay vs DLA anticipation for 21/06/ Figure 4: ATFM delay vs DLA anticipation for 22/06/ Figure 5: Example of Regulation s slot list output from TACOT Figure 6: ATFM delay vs DLA anticipation Non-Weather regulations

8 Page: 8 1 INTRODUCTION Air Traffic Flow Management (ATFM) is a service aiming at providing safe, orderly and expeditious flow of air traffic by ensuring ACC capacity is utilised to the maximum extent. A Centralised Air Traffic Flow Management (ATFM) service is established within the ICAO (EUR) Region to optimise the use of air traffic system capacity. The Central Flow Management Unit (CFMU) in Brussels provides this service in conjunction with Flow Management Position (FMPs) established at each ACC. In case of demand exceeding capacity on a given ACC, the ATFM service assigns ground regulation slots (ATFM slots) to flights going through this very ACC. Besides the ATFM service, coordinators at coordinated airports assign airports slots to airlines in order to ensure the best use of airport capacity and to avoid the airline demand to exceed capacity. The actual airport slot assignation process is based on the principle of grandfather rights (an airline, which uses a slot intensively in one season, has a right to operate that slot in the next equivalent season). Airlines can switch the use of particular slots between routes and between aircraft types. This regime also allows, under some conditions, the exchange of slots between airlines. The resulting traffic is managed at a number of different planning and tactical levels to keep actual traffic levels aligned with the capacity of the airport s infrastructure and ATC systems. 1.1 ABCD overview The ABCD (Aircraft-Based Concept Development) concept consists in using the aircraft registration in order to link the individual flight plans. It proposes to improve flight predictability by linking flight plans using the same aircraft through the aircraft registration information. The benefits, brought by the ABCD concept, have been studied in a previous study [1] and proved through macroscopic analyses performed on CFMU files. Even if these analyses demonstrated the benefits, they have not determined precisely the magnitude of the benefits. In the same way, the costs, incurred by the implementation of an ABCD concept have not been defined precisely. As ABCD should help to control reactionary delays, improving the predictability of aircraft operations, the over-riding factor in controlling the financial costs of delays, aircraft operator will be able to improve their punctuality, leading to reduced tactical and strategic costs of delays ; ATC / CFMU will benefit at both local and network level. ABCD will provide a better picture of future traffic flows, thus improving its management. It could reduce reactionary delays through better slot compliance. In the long term Air Traffic Control Centre will minimize the waste of their effective capacity as a consequence of the increased confidence in the predictability of traffic flows; 8

9 Page: 9 Airport Operator will be able to improve service provision to their customers through better allocation of resources as they could be informed long in advance of the future potential disruption in term of flight plan schedule consistency. These apply to both the tactical level, through stability in gate and stand allocation, as well as strategically, as better use of infrastructures supports greater passenger throughput. Airports should also be able to provide better information to their customers. Overall, the airport quality of service should be enhanced; Ground Handler will be able to improve the use of their resources, saving costs and providing an improved level of service; Low-cost and regional airlines consider that ABCD would facilitate their delay management and optimize their slot allocation process and thus they stated their interests in the ABCD concept implementation. Moreover, thanks to the linkage of individual flight plans, it has been inferred that it could be possible to provide more accurate predictions of the downstream legs of an aircraft itinerary, in particular when a flight suffers from disruptions (involving delays). It has been shown through the analyses conducted last year, during the first part of the ABCD project, that thanks to the linkage of the individual flight plans, the ABCD concept could improve the predictability and the efficiency of the airlines, ATM and airports operations. In particular, in the case of one regional airline, it has been proved through some real and tangible examples, that the sooner the delay messages anticipation for a given flight, the smaller its ATFM delay. In addition, the first part of the project focused on substantiating this point over a large scale basis and on: showing to low-cost and regional airlines the interest of using ABCD as a tool to minimize ATFM delay, establishing to major airlines that implementing ABCD concept would also benefit them as a result of global network optimization, proving to ATM stakeholders that the use of ABCD enhance the predictability of the ATM network and hence reduces its uncertainty. 1.2 Project background Last year, ADV Systems and ALG carried out together the first part of the ABCD project [1]. They stressed the following points: It has been shown through qualitative (interviews and analysed examples) and quantitative analyses that ABCD implementation could bring tangible benefits to ATM stakeholders (airlines, CFMU, airports). - Quantitative macroscopic analyses have proved that, whatever the information media used for the notification of a delay message, the earlier the notification of the delay messages the lower the ATFM delay. They have also shown that airlines do not generally notify delay messages more than 20 to 40 minutes in advance. - Thanks to the linkage of flight plans, allowed by the aircraft registration number, the ABCD concept would permit to better anticipate delay 9

10 Page: 10 messages than nowadays. Delay messages would be notified earlier to the CFMU, which would result for the delayed flights into a decrease of their ATFM delay. - The reduction of ATFM delays would provide aircraft operators with a financial gain related to the cost of delay. For the CFMU and ATM stakeholders, ATFM delay reduction would mean a better use of the available capacity. - Thus, the implementation of an ABCD related tool would bring airlines financial gains and allow the CFMU a better use of the available capacity. However, it has to be acknowledged that ABCD concept implementation should not be imposed to all actors. For low cost and regional airlines: The interviews have established that the implementation of ABCD provides them with an efficient tool to recalculate automatically new EOBT for subsequent flights, using the same aircraft as an initial delayed flight, once the delay on the initial flight have been detected and found to be propagated throughout the subsequent flights. Those airlines have stated that they were ready to send the necessary data to feed such a tool as this tool will provide them with the feeling of being dealt by the CFMU as major airlines. Even though the generation of automatic EOBT could bring some issues in terms of responsibility, these airlines are keen on the implementation of an ABCD-like tool. For major or flag carrier airlines: In the case of major disruptions, those airlines have the ability and the resources of swapping aircraft for a given flight incurring too much delay. In some cases, they even have some tools comparable to what ABCD provide and it appears that they want to keep the ability of swapping aircraft readily. Thus, they are reluctant to use an ABCD tool when they have their own ABCDlike tool. Therefore, it is clear that the implementation of ABCD should not be imposed to all airlines. 1.3 Project purposes and scope The second phase of the ABCD project to be performed during 2008 and part of 2009 is driven by two objectives: The first goal consists in specifying and prototyping an ABCD tool. The first phase of this main task will be to conduct a Cost Benefit Analysis of the ABCD concept when implemented by an airline. The benefits will be evaluated using 10

11 Page: 11 as input data results from TACOT (1) simulations on real traffic [4]. Those simulations will help to build a sturdy and realistic ABCD Benefits Model based on real quantitative values that will complement the estimates and interviews with airlines that have been done in previous works. In particular, the simulations will allow a precise estimation of delay benefits which will be translated into financial gain. In the same way, the technical implementation of an ABCD concept requires to specify how this concept would technically fit with existing ATM systems and especially the airline systems. In particular, the way, information and data from existing systems could be used in order to implement this concept, will be analyzed and a concrete implementation model will be proposed. In particular, the study will produce some functional and operational specifications which will help to produce an ABCD prototype PC based tool. The second objective of the project intends to prove that the earlier the notification of delay messages to the CFMU, the lower the number of unused ATFM slots. Indeed, it was stressed that the overall proportion of missed ATFM slots is not negligible. Because the lack of anticipation was identified as a possible cause for unused ATFM slots, and because an ABCD-like tool could improve the anticipation of it users, a missed slot analysis was recommended in addition to the development of ABCD [2]. Consequently, it would demonstrate that improving delay messages anticipation is beneficial to everybody, airspace users, as well as network management. In that sense, it would point to the virtues induced at central level by the local use of a distributed system like ABCD. This second phase of project is structured as a set of seven work packages that develop, simulate and validate the ABCD concept. As said previously, this study revolves around two themes: the first part, which includes WP3, 4, 5, 6 and 7, focuses on ABCD development. The second axis, WP8 and WP9, is focused on the impact of the delay messages anticipation on unused slots. WP3: Cost Benefits Analysis. WP3 consists in running a Cost Benefit Analysis on the ABCD tool implemented by an airline. One of the purposes of WP3 will be to evaluate in a precise way the possible benefits brought by the ABCD concept, by performing TACOT simulations on real traffic of one specific airline (low cost carrier). Those simulations will enable to measure the gain in ATFM delay when the delay message is notified in advance, resulting in a financial benefit for the airline. The other purpose of WP3 is to calculate precisely the costs supported by the airline for the ABCD implementation. WP4: ABCD tool prototype definition. In order to define an ABCD tool prototype, it is necessary to define ABCD tool objectives as well as a framework for the operational and functional implementation of this tool. Firstly an initial concept of operation strategy will be defined paving the way to operational and functional requirements. Based on this strategy, the concepts of operation will be carefully selected, trade-offs documented and finally the operational, functional and non-functional requirements of the ABCD tool will be derived, as well as consistency and completeness of these requirements will be checked. 1 TACT Automated COmmand Tool (TACOT) is a simulation platform for fast-time ATFM simulations 11

12 Page: 12 WP5: ABCD tool prototype development. WP5 consists in developing and testing the functional prototype for the ABCD tool (at airline level) defined in the previous WP4. The tool will be able to link the different FPLs belonging to several itinerary legs of the same aircraft through the aircraft registration. This will be done at the airline operations centre. WP5 will contain two main activities: first, the tool functional prototype development and second the validation of the tool with one or two airlines. WP6: Tool upgrade at CFMU level. The aim of WP6 is to analyse the implementation of the ABCD concept at the CFMU level and in particular to raise the technical and juridical obstacles brought about by such an implementation and to provide some solutions to overpass those obstacles in order to be able to implement the ABCD concept at the CFMU level. WP7: Final ABCD Report. WP7 will consolidate the work done in the previous WPs and draw conclusions on: benefits and costs of ABCD at airline level (WP3); specifications, prototyping and validation results of the ABCD tool (WP4 & WP5); regulatory role of the CFMU in a distributed environment; the assets/liabilities of a implementation at central level (WP6); ABCD in tomorrow s environment, taking into account SESAR achievements (WP6); and unused ATFM slots study results (WP8 & WP9). WP8: Simulation definition for the unused ATFM slots study. While at WP3 simulations will be used to determine the gains brought to an airline by a local implementation of the ABCD concept, WP8 will use TACOT simulations to prove that the earlier the notification of delay messages to the CFMU, the lower the number of unused ATFM slots and the lower of overall ATFM delay, while maintaining the same level of overloads. Consequently, it would demonstrate that improving delay messages anticipation is beneficial to everybody, airspace users, as well as network management. WP8 aims at the analysis of historical data, the selection of a relevant traffic sample and the definition of simulations scenarios. Two main tasks are considered: - Scenarios definition. First, a baseline scenario will be defined on the basis of archived CFMU data (one or several Traffic Volume(s) frequently regulated; at least one week of traffic will be addressed to get significant results; for each regulation part of the sample, DLA messages will be identified: timestamp of the message, new EOBT and difference between both, i.e. anticipation). Secondly, alternative anticipation scenarios will be built, mainly through a modification of the DLA timestamps to simulate an improvement of anticipation, for instance 15 min, 30, 45, 1h, 1h15 before the new EOBT. The objective is to make a comparative assessment between the baseline scenario results and those resulting form the alternative scenarios. - Simulations preparation. This task aims at preparing the simulations in coordination with the TACOT facility managers to: adapt the scenarios, depending on the possibilities and limitations of the simulation platform; convert the scenarios into input files with the right format; and set up preferences regarding the simulations execution (rendering of the simulations vs. running time, selection of the output files ). 12

13 Page: 13 WP9: Simulation results analysis for the unused ATFM slots study. WP9 aims to develop the post-processing and analysis of the simulation results, performed for the unused ATFM slots analysis. Two main tasks are considered: - Simulations execution. This task will be performed by the TACOT facility managers who will monitor the simulations execution; provide early feedback; and adjust the simulations if needed (reconfigure the simulator, add/remove I/O, adapt scenarios, provide additional scenarios ) based on the ABCD project requirements. The baseline scenario will be simulated to replay real operations and serve as a reference for the alternative scenarios; and the anticipation scenarios will be simulated. - Results analysis. This task will be two-pronged: First, macroscopic ATFM indicators will be derived from the simulation results for the baseline scenario and for the anticipation scenarios, mainly: number of unused ATFM slots; total ATFM delay; and possibly other relevant indicators such as: number of delayed flights; and maximum ATFM delay. Second, the scenarios will be confronted to concatenate the results and express each indicator as a function of anticipation to draw the following relationships: number of unused ATFM slots = f(anticipation); total ATFM delay = f(anticipation). What is expected for each indicator is a monotonous function, decreasing with anticipation. In that case: 1.4 Purpose of the document The recommendations drawn from the Analysis of Unused ATFM Slots ( the sooner, the better ) would be validated; The positive effects of an ABCD-like tool on network operations would be evidenced. The present document consolidates the results of WP8 Simulation definition for the unused ATFM slot study, constitutes the first deliverable of the project and intends to: Remind the concept of ABCD, which consists in using the aircraft registration; Present the purposes and scope of the unused ATFM slots analysis; Propose a simulation methodology for the envisaged unused ATFM slots analysis to be performed by the TACOT facility managers; Define the scenarios to be simulated: selection of traffic sample (scope and set of selected days); justification of the selection; and description of the Baseline and the Alternative scenarios; 13

14 Page: 14 Define inputs and outputs for the simulations; and consolidate the set of simulation specifications and requirements agreed with the TACOT Facility managers; Describe the envisaged simulation execution procedure and present the planned schedule for the simulations; Propose conclusions and way forward for the simulation execution and results analysis for the unused ATFM slots study, to be implemented during WP9. The contents of the document, specially the methodology, specifications and schedule for the simulations and the definition of scenarios to be simulated, have been determined in close cooperation with the TACOT Facility managers. 1.5 Structure of the document The document is split in 7 sections and 2 annexes: Section 1 Introduction presents the context of the project and the purpose of the present document; Section 2 Principles of the unused ATFM slots simulations presents principles from previous studies referring unused ATFM slots analysis and establishes the scope and objectives for the simulations; Section 3 Simulation methodology proposes the methodology for the preparation, validation and running of the unused ATFM slots simulations; Section 4 Definition of scenarios presents the proposed scenarios to be simulated: Baseline and alternative scenarios definition, selection and justification of the traffic sample; list of outputs required from simulations for each scenario; Section 5 Simulations execution procedure and schedule proposes the planned simulation calendar; Section 6 Expected results and further analysis introduces the set of analysis to be performed from the simulations results; Section 7 Conclusions and next steps summarises main concussions and following activities regarding the scope of the unused ATM slots analysis; Annex 1 ATFCM technical overview overview of necessary slot allocation process and Computer Slot Allocation Process (CASA) concepts in order to understand analysis presented in the document; Annex 2 Operational data for the unused slots analysis presents a list of preliminary results for the selection of days, obtained from available CFMU databases. 14

15 Page: 15 2 PRINCIPLES OF THE UNUSED ATFM SLOTS SIMULATIONS 2.1 Unused ATFM slots background In 2000 the PRU mandated a study to analyse the overall impact of unused ATFM slots on performance [3]. It identified for a regulation sample the proportion of unused slots and showed that if those slots could be recovered such regulations would: Generate lower ATFM delays; Delay fewer flights; Better smooth the demand; The study also underlined that those benefits could be obtained if all the information concerning potential slot recovery were known as soon as possible by the ATFM system, in particular regarding operational disturbances. In 2007, the ABCD project focused on specific information exchanges: the DLA/CHG (delay/modification) messages sent to the CFMU by Aircraft Operators to notify a new EOBT. Preliminary results showed that: DLA/CHG messages are often notified at short notice by airlines. Consequently, ATFM slots already allocated to delayed flights may not be recovered by the ATFM system; The late notification of a DLA/CHG message is possibly due to a lack of anticipation. For some airlines, the project identified the need for a decisionsupport system that would help them anticipate better in particular through the monitoring of delay propagation, when the same aircraft is used intensively and flies successive legs during the day of operation. Airline RYR DLA message CFMU EOBT 9:58 11:40 ETOT RYR465T 46465T 11:50 Time Delay anticipation: 102 minutes 15

16 Page: 16 Figure 1: Delay message anticipation concept 2.2 Objectives of the unused ATFM slots simulations In the wake of the Analysis of Unused ATFM Slots, simulations aim to validate the following assumption: Slot recovery is improved when delay messages are notified earlier More precisely, the purpose of the simulation results and the required posterior analysis is to set out the relationship between delay messages anticipation and a number of macroscopic ATFM indicators: number of unused slots; overall ATFM delay; number of delayed flights; maximum ATFM delay in order to show that the efficiency of a regulation increases when delay messages are sent earlier to the CFMU. The ulterior motive is to show that the local implementation of a distributed system like ABCD may have positive effects at network level i.e.: Contribute to the optimisation of capacity use by the ATFM system, in terms of used slots; At a lower cost, in terms of ATFM delays. As said before, the study will rely on TACOT simulations (fast-time ATFM simulations) and will be based on a comparative assessment between alternative anticipation scenarios, derived from a baseline operational scenario. For the purpose of the unused ATFM slots simulations, a slot is said to be unused if it is still available when the regulation is terminated, provided that it is not cancelled beforehand: Some slots are available just because there is no demand for them. For the purpose of the study this slots will be called free slots. Others, called lost slots, are available because due to real-time events they cannot be allocated despite some demand for them. For example, the slot is allocated to a flight which notifies a delay message with poor anticipation. The slot is released, but cannot be recovered by the next flight on the (slot) list because it is already airborne, departing from a remote aerodrome. The normative system definition of a lost slot is the following [5]: 1) A slot S in a regulation R is considered as a lost slot if it satisfies the following criteria: a) Status = Available b) Rate type = Normal (pending slots are thus excluded) c) It exists at least one flight such as its ETO is before S slot reference time and its CTO after it. The idea is that this flight could have been placed in this slot. 16

17 Page: 17 2) It is worth pointing out that one slot can only be counted once as a lost slot, even if several flights meet the criterion 1)c). Likewise, once a flight has been identified as a potential user of a lost slot, it can not be used anymore to identify other lost slots. 3) For each regulation, two different number of lost slots is displayed in the detail area depending on the way they are computed : a) The column Lost Slots contains the number of all lost slots in the regulation according to the definition stated in 1)c). The column Penalising Lost Slots, contains the number of lost slots in the regulation but the criterion 1)c) is modified so as to take into account only the flights for which the regulation is the most penalising one. 3 SIMULATION METHODOLOGY The proposed simulation methodology for the TACOT simulations, to be performed to support the unused ATFM slots analysis, should comply with the following requirements, which have been agreed with the TACOT facility managers: The unused slots analysis simulations (WP8 & WP9) will be performed in parallel with the simulations for the ABCD cost and benefit analysis at airline level (WP3): - Though the scope of the simulations is different for WP8 and WP3, required outputs and simulation methodology and specifications will be mainly common for both simulations activities; - In order to reduce the number and the total time of the TACOT simulation executions, and to keep in a easier way the management of the outputs from TACOT; Selected traffic sample will contain at least 6 days, included within no more than 2 AIRAC cycles. As simulations will run in parallel, some of these days will be common to the WP3 simulation; A baseline scenario and a set of alternative anticipation scenarios will be simulated, in order to perform the required comparative assessment: - Baseline and alternative scenarios will be run for each day of the selected traffic sample; - Baseline scenario design and specifications will be common for WP8 and WP3, so each run of the baseline scenario will provide outputs for WP8 and WP3 at the same time. In the other hand, alternative scenarios will be prepared separately for WP8 and WP3, therefore independent runs will be required for each WP; Simulations initialisation: a first phase for simulation preparation will be required. Baseline and alternative scenarios will be run for 1 or 2 days of the selected traffic sample in order to calibrate the TACOT platform, to validate the required outputs for each scenario and to confirm the selected set of alternative 17

18 Page: 18 scenarios. Once these simulation specifications are validated the baseline and alternative scenarios will be run for the rest of the days of the selected traffic sample. Proposed simulation methodology is structured in the following phases, in chronological order: 1. First Simulation Cycle -Simulation preparation. For 1 or 2 days of the selected traffic sample a complete sets of runs (baseline and alternatives scenarios) will be performed: a. Baseline scenario execution: first simulation runs will be used for a initial calibration of the TACOT platform and initialise the simulations; b. Baseline results analysis: first analysis of results will be used to validate the TACOT platform calibration and the baseline scenario requirements: traffic scope, scenario design, required outputs c. Alternative scenario execution: in order to perform a complete simulation set, alternative scenarios will be run during the preparation cycle for the 1 or selected days; d. Alternative results analysis: fist simulation cycle will end with the validation of the alternative scenarios and the final agreement on the simulation specifications: traffic scope, scenarios selection, required outputs, simulation methodology 2. Second Simulation Cycle: Once the simulation methodology is validated the set of scenarios will be run for the rest of the days of the selected traffic sample: a. Baseline and alternative scenarios execution; b. Baseline and alternative results analysis. As said before both simulation cycles will be run in parallel for WP8 and WP3 activities. FIRST SIMULATION CYCLE (only 2 selected days) SECOND SIMULATION CYCLE (rest of the days) WP3 WP8 Baseline Scenario Execution Analysis of Results Baseline Scenario Alternative Scenarios Execution Analysis of Results Baseline Scenario Baseline & Alternative Scenarios Execution Analysis of results Baseline & Alternative Scenarios Platform calibration & Baseline Scenario validation Alternative Scenarios validation Validated Scenarios and Simulation requirements Figure 2: ABCD simulation methodology 18

19 Page: 19 4 DEFINITION OF SCENARIOS In the present section are defined the scenarios to be simulated, including the baseline and the alternative anticipation scenarios. Firstly, the traffic sample need to be chosen and the traffic scope defined; in addition the justification for the selected days of the traffic sample is presented. For each scenario (baseline and alternatives), the simulation specifications are presented: scenario design, inputs, required outputs and general execution guidelines. As for the simulation methodology presented in the previous section, scenarios specifications have been set up in close cooperation with the TACOT facility managers. 4.1 Traffic sample First of all, the traffic sample should be defined, in terms of simulations scope and selection of the specific days. For this purpose, historic databases from CFMU in order to select our sample from the 2007 traffic records Traffic Scope For the purpose of the unused ATFM slots simulations, the traffic sample units will be the activated regulations. Simulations scenarios will be run for each day of the traffic sample focusing only on the regulated flights, including those affected by non weather and weather regulations. For the scope of the simulation, scenarios execution will focus on all regulations, although the non-weather regulations are expected to be most appropriate for the results analysis purposes. Indeed, due to its own nature, weather regulations are difficult to predict and variable as they can evolve when weather conditions change. Under these circumstances anticipation in flight s schedule variations are more difficult to predict. Moreover, expected benefits from delay messages anticipation are less important as flow rate of the regulation will evolve continuously leading to a lack of predictability even if all flights would be able to anticipate their previous flights delay. The analysis will be initially split in 5 groups, one for each regulation type: C ATC capacity G Aerodrome Capacity S ATC staffing T Equipment (ATC) W Weather Non-Weather 19

20 Page: 20 Therefore, simulations will focus on the slots of those regulations with the following particularities: Used slots from all the regulations of the selected day Unused slots from all the regulations of the selected day As introduced before, a slot is said to be unused if it is still available when the regulation is terminated, provided that it is not cancelled beforehand: Some slots are available just because there is no demand for them. For the purpose of the study this slots will be called free slots. Others, called lost slots, are available because due to real-time events they cannot be allocated despite some demand for them. For example, the slot is allocated to a flight which notifies a delay message with poor anticipation. The slot is released, but cannot be recovered by the next flight on the (slot) list because it is already airborne, departing from a remote aerodrome. The simulations only intend to play with the timing of real-time events, without any change to the demand (EOBT will not be modified). Thus a slot which is lost in the baseline scenario could be recovered in another scenario. Conversely, a slot for which there is no demand in the baseline scenario should remain unused in another scenario Selected days For the purpose of the unused ATFM slots analysis, baseline and alternative anticipation scenarios will be performed on 6 days of traffic. All of them belong to AIRAC cycles number 296 (from 07/06/07 to 04/07/07) and 297 (from 05/07/07 to 01/08/07). Selected Days Weekday/ weekend AIRAC Cycle Number of regulated flights 14/06/07 WD /06/07 WD /06/07 WD /06/07 WD /06/07 WE /07/07 WD Within these days, there are 4 days in common with WP3 simulation activities: 21/06/07, 22/06/07, 30/06/07 and 20/07/07. 20/07/07 and 21/06/07 are top of the list in the simulations schedule since it will be used for the first simulation cycle. For WP3, 4 extra days have been selected: 09/06/07, 18/06/07, 18/07/07 and 28/07/07. 20

21 Page: Justification of the selection For the purpose of the unused ATFM slots analysis, the proposed traffic days have been chosen following several criteria: High values of total ATFM delay; High density of regulated flights (specially due to non-weather regulations); High density of regulated flights that sent a DLA message; High values of ATFM delay for those regulated flights; Significant % of unused slots. As shown in previous studies, the effect on the overall ATFM delay and on the % of unused slots of anticipating the delay messages is expected to be more important at severe regulations, which comply with the criteria above indicated. Therefore simulations should focus on severe regulations, which correspond to regulations imposing heavy ATFM delays to affected flights. Focusing on ATFM delays with high values is of interest as the corresponding delayed flights may have an impact on airlines operations as well as on CFMU since the higher the rate of unused slots, the higher the waste of capacity. Using available operational data from CFMU databases (CIR, DANCE), some interesting results have been obtained for the selected days (14, 15, 21, 22, 30 of June 2007 and 20 of July 2007), that confirm in advance the suitability of the selection. The following table shows the ranking of the days of 2007 with the highest total ATFM delay. The selected days (in bold) are within the top 20 days: Ranking position Day ATFM delay (min) 1 12/04/ /07/ /06/ /06/ /06/ /06/ /01/ /05/ /11/ /07/ /06/ /01/ /06/ /07/ /10/ /06/ /06/ /06/ /09/ /07/

22 Page: 22 In addition; should be required that these days also present high rates of regulated flights; preferably due to non-weather regulations. In this sense, for 4 of the selected days (14, 15, 21 and 22 of June 2007) some key operational data have been obtained in order to confirm in advance its suitability for the simulation and posterior analysis, as shown in the following table: Day 14/06/07 15/06/07 21/06/07 22/06/07 Flights Regulated flights ,39% ,17% ,03% ,09% NW Regulated flights ,71% ,30% ,82% ,38% NWR flights sending DLA message ,84% ,46% ,25% ,37% ATFM delay ATFM delay R flights ,92% ,97% ,98% ,94% ATFM delay NWR flights ,41% ,70% ,29% ,23% ATFM delay NWR flights sending DLA message ,54% ,34% ,90% ,79% ATFM delay/r flight 20,09 20,67 21,37 18,48 ATFM delay/nwr flight 17,44 17,28 16,89 17,87 ATFM delay/nwr flights sending DLA message 17,78 17,47 17,35 16,57 The following graphs show the average ATFM delay per flight against the anticipation for the flights of days 21 and 22 of June 2007: 70 Average ATFM delay per flight (min) Anticipation of the DLA / EOBT of the DLA (min) Figure 3: ATFM delay vs DLA anticipation for 21/06/07 22

23 Page: Average ATFM delay per flight (min) Anticipation of the DLA / EOBT of the DLA (min) Figure 4: ATFM delay vs DLA anticipation for 22/06/07 Simulation results analysis will also preferably focused on non-weather regulation as weather regulations due to its lack of predictability may trigger different behaviour from airlines and probably present different results in term of linking the delay messages anticipation time and ATFM delay values. In addition, for the day 22 of June 2007 a regulation level analysis is performed in order to determine some figures regarding unused slots. Results are presented for three non weather regulations: Regulation ID EPD22 LGGIL22A LOEAL22 Regulation type C C S Duration (hours) 7,67 6,00 9,00 Flights Flights sending DLA message ATFM delay ATFM delay flights sending DLA message ATFM delay/r flight 19,67 27,12 38,97 ATFM delay/nwr flights sending DLA message 25,60 24,94 37,03 Total slots Unused slots % Unused slots 4,93% 7,92% 3,32% 23

24 Page: Baseline Scenario The baseline scenario should be envisaged as the reference scenario to which the alternative scenarios will be compared, in order to assess the effect of the delay messages anticipation to the ATFM delay and the number of unused slots. Therefore, as the reference scenario, fully consistency with real situation is required. In addition; the baseline scenario should be used to calibrate the platform and to validate the simulation methodology and the required TACOT outputs Scenario design The baseline scenario should represent the real traffic situation of the selected days. TACOT platform will simulate the real situation and present the required parameters outputs: ATFM delay, anticipation of the DLA messages, and unused slots per regulation. The baseline scenario will be unique for WP8 and WP3, not requiring different preparation and able to be run for both simulation activities at the same time Required outputs As said before, the simulation of the baseline scenario will be used to validate the methodology and baseline scenario against the operational data to obtain the results to be compared with the results of the alternative scenarios. Some of the required outputs described below will be redefined after first simulation execution, once the first analysis is performed and real outputs requirements are confirmed. For the unused ATFM slots analysis three types of metrics will be relevant as results of the simulation: Indicators per regulation (applied to each regulation considered in the simulations, preferably non weather) - Slot list of the regulation life cycle. Including for each slot time: the allocated flight identified by its call sign; Estimated Off Block Time (EOBT); Estimated Take Off Time (ETOT); Calculated Take Off Time (CTOT); Estimated Time Over the reference point of the restricted location (ETO); Calculated Time Over the reference point of the restricted location (CTO); Actual Time Over the reference point of the restricted location (ATO); and information about the status of the slot: forced, exempted, available or allocated. Some slots are unused, which means that slots are not allocated to flights; 24

25 Page: 25 Figure 5: Example of Regulation s slot list output from TACOT - Number of lost slots: non-penalising and penalising; - Number of free slots. Indicators per flight (applied to each flight of the used slots considered in the simulations) - Flight identification data: aircraft Id; regulation Id; regulation type (W, C, G, S, T, ); - Actual ATFM delay; - Anticipation of the delay (= lapse of time between the DLA message and the new EOBT contained in the message); - Historic record of times: EOBT, CTOT, time stamp of the DLA message; - ATFM delay resulting directly from the first DLA message (= CTOT contained in the first SRM / SAM following the first DLA minus EOBT of the first DLA message); - Anticipation of the first DLA message: 1. with respect to the previous EOBT; 2. with respect to the EOBT contained in the DLA message. Statistics indicators (applied to the set of the flights considered in the simulations) - Total ATFM delay of these flights; - Average ATFM delay per flight; - Maximum ATFM delay; 25

26 Page: 26 - Number of regulations: total; weather and non weather; per type of regulation (W, C, G, S, T, ); - Number of lost slots: non-penalising and penalising. These outputs will be extracted from TACOT files, which will be common for WP8 and WP3 simulation activities Scenario execution This section provides with information necessary to run the baseline scenario. For each day to be simulated, the simulator will replay the day in full The outputs will be extracted whenever necessary: - When the output is not time-dependent (e.g. message contents), it shall be extracted whenever possible (e.g. after the message is sent); - When the output is time-dependent (e.g. slot list), it shall be extracted each time the regulation is modified. To minimise the total running time of the simulations and avoid simulation inconsistencies related to late flight updates, flight progress (DEP, ARR, FSA, CPR) messages are not taken into account. Under such conditions, the average running time is 10 hours per run. 4.3 Alternative Anticipation Scenarios In order to determine the effect of anticipating the delay message, alternative anticipation scenarios simulation is required. As shown at previous studies early anticipation of the delay message will lead to a reduction of the ATFM delay ATFM delay in minutes Average ATFM delay 18, Anticipation in minutes Figure 6: ATFM delay vs DLA anticipation Non-Weather regulations 26

27 Page: 27 In addition; it is expected that the number of the unused slots will be reduced as the anticipation of the delay messages is earlier Scenarios design The alternative scenarios design principles consist in assuming that some flights better anticipate reactionary delays, hence notify them earlier to the CFMU. This section indicates which messages shall be modified and how, according to the simulation scenario. The goal of the validation activity is to measure the ATFM delay gain and the reduction of unused slots when aircraft notifies earlier a delay message to the CFMU. Thus, alternative scenarios have been set up in such a way as to vary the timestamp of a DLA message. In each scenario, it is assumed that each one of the delay messages sent by the a/c to the CFMU is notified X minutes in advance with respect to the baseline scenario. X is therefore the parameter that varies from a scenario to another one. The change of the timestamp will be of course applied only to the flights considered in the baseline scenario, i.e. those that are regulated and sent a DLA message. Thus, the data that shall be changed in the operational log is the filing time (timestamp) of one type of input message, the DLA (delay) messages identified as IMDLA in the log. The contents of the message shall not be changed, unless otherwise specified. The following table summarizes how the scenarios are designed: Input message : Scope : DLA message DLA corresponding to the flights considered in the scope of the simulation, depending on the conditions/ restrictions (see hereunder) are fulfilled Change : Timestamp of the message Change in the contents : Conditions, restrictions : None Check if the timestamp of the DLA message is later that the timestamp of the flight plan message 27

28 Page: 28 For the purpose of the unused ATFM slots analysis 10 alternative scenarios are first proposed: Scenario Anticipation (X minutes in advance with respect to the baseline scenario) 1 10 min 2 20 min 3 30 min 4 45 min 5 60 min 6 90 min min This first selection of alternative scenarios responds to several criteria: No scenario beyond 120 minutes of anticipation will be considered because flights are regulated 2 hours before departure (as shown at figures 3 and 4 the effect on ATFM delay for anticipations earlier than 120 minutes does not change); First scenarios will be closer to each other in anticipation time in order to determine the sensitivity of the ATFM delay depending on the applied anticipation. This selection of alternative scenarios, common for WP8 and WP3, will be validated as a result of the first simulation cycle. If similar results are obtained for different scenarios, only one of those scenarios will be simulated in order to reduce the total running time of the simulations. Differently from the baseline scenario; alternative scenarios will be required different preparation for WP8 and WP3, since the scope of the flights; that required a modification on the delay messages anticipation; is different for each WP. Therefore, independent alternative scenarios simulation runs will be necessary for each simulation activity Required outputs The outputs of alternative scenarios are the same as for the baseline scenario. 28