EUROCONTROL EXPERIMENTAL CENTRE · V1.1 15.6.05 Approved version . EUROCONTROL Paradigm Shift - Research Agenda ... Proof of Concept Assessment. 23rd Digital Avionics System Conference,

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EUROPEAN ORGANISATION FOR THE SAFETY OF AIR NAVIGATION

EUROCONTROL

EUROCONTROL EXPERIMENTAL CENTRE

PARADIGM SHIFT RESEARCH AGENDA

EEC Note No. 16/05

Project INO-1-AC-SHIF

Issued: June 2005

REPORT DOCUMENTATION PAGE

Reference: EEC Note No. 16/05

Security Classification: Unclassified

Originator: EEC/INO (INOvative Research Area)

Originator (Corporate Author) Name/Location: EUROCONTROL Experimental Centre Centre de Bois des Bordes B.P.15 F - 91222 Brétigny-sur-Orge Cedex FRANCE Telephone: +33 (0)1 69 88 75 00

Sponsor: EUROCONTROL Experimental Centre

Sponsor (Contract Authority) Name/Location: EUROCONTROL Agency 96, Rue de la Fusée B-1130 Brussels Telephone: +32 2 729 90 11 WEB Site: www.eurocontrol.int

TITLE: PARADIGM SHIFT

RESEARCH AGENDA

Authors L. Guichard S. Guibert

D. Dohy (STERIA) J.Y. Grau (STERIA) K. Belhacene (CS)

Date 06/2005

Pages x + 42

Figures 3

Tables 0

Annexes 0

References 7

Project INO-1-AC-SHIF

Task No. Sponsor

Period 2004

Distribution Statement: (a) Controlled by: Vu Duong, Head of INO (b) Special Limitations (if any): None Descriptors (keywords): Research axis, contract of objective, operational plan, target window, decentralised design, strategic traffic, highway, coexistence, dual airspace.

Abstract: This report follows the Paradigm Shift Operational Concept Document, which was developed at the EUROCONTROL Experimental Centre in 2004.

The Research Agenda describes the main research axis relating to the concepts described by Paradigm SHIFT and highlights some essential but, by no means exhaustive, questions requiring further investigation in order to validate the solutions proposed for the development of the air transport system.

This research agenda is proposed to become the backbone of the advanced concept thread in INO.

Paradigm Shift - Research Agenda EUROCONTROL

Project INO-1-AC-SHIF - EEC Note No. 16/05 v

REVISIONS

Release Date Subject

V0.0 Draft 3.1.05 Draft version for approval

V1.0 Initial 17.1.05 Initial version

V1.1 15.6.05 Approved version

EUROCONTROL Paradigm Shift - Research Agenda

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Project INO-1-AC-SHIF - EEC Note No. 16/05 vii

TABLE OF CONTENTS

LIST OF FIGURES .......................................................................................................... VIII

REFERENCES .................................................................................................................. IX

1. INTRODUCTION...........................................................................................................1

2. THE CONTRACT OF OBJECTIVE...............................................................................4 2.1. THE WORK OF TACTICAL CONTROL OPERATORS ON THE GROUND .................. 4

2.1.1. Workload ...........................................................................................................4 2.1.2. Situational Awareness .......................................................................................5 2.1.3. Human-Machine Interfaces ...............................................................................6 2.1.4. Support Systems and Aids ................................................................................7 2.1.5. Job Transition ....................................................................................................7

2.2. THE WORK OF FLIGHT CREWS.................................................................................. 8 2.2.1. The Tasks of Flight Crews.................................................................................8 2.2.2. From Liability to Shared Liability?......................................................................9 2.2.3. Technological Support for Data Exchange and Sharing Between Ground

and Air..............................................................................................................9 2.3. OPERATIONAL CONTINUITY..................................................................................... 10

2.3.1. The Interface Between Tactical Control Operators .........................................10 2.3.2. The Interface Between Flight Crew and Tactical Control Actors .....................11 2.3.3. Operational Responsibility...............................................................................12

3. THE OPERATIONAL PLAN .......................................................................................13 3.1. THE ACTORS .............................................................................................................. 13

3.1.1. Modelling .........................................................................................................14 3.1.2. Functional Approach........................................................................................14 3.1.3. "Political" Approach .........................................................................................16 3.1.4. Environmental Approach .................................................................................16 3.1.5. Organisational Approach .................................................................................16

3.2. THE PROCESS............................................................................................................ 17 3.2.1. Negotiation Protocol ........................................................................................17 3.2.2. Data Models ....................................................................................................18 3.2.3. Decision-Making Aids ......................................................................................20 3.2.4. Dissemination of the Contract of Objective .....................................................21 3.2.5. Renegotiation ..................................................................................................21

3.3. INFRASTRUCTURE .................................................................................................... 23 3.3.1. Network Architecture .......................................................................................23 3.3.2. System Architecture ........................................................................................23 3.3.3. Interoperability .................................................................................................24

4. THE TARGET WINDOWS ..........................................................................................25 4.1. OPERATIONAL DECISIONS AND TARGET WINDOWS............................................ 26 4.2. DISRUPTIVE FACTORS.............................................................................................. 27

5. DECENTRALISED DESIGN .......................................................................................30 5.1. AIRSPACE DESIGN AND TARGET WINDOWS ......................................................... 30

5.1.1. Traffic Regulation ............................................................................................30 5.1.2. Internal Cooperation ........................................................................................30


viii Project INO-1-AC-SHIF - EEC Note No. 16/05

5.1.3. Flight Paths......................................................................................................31 5.2. STRATEGIC TRAFFIC................................................................................................. 31

5.2.1. Relevance........................................................................................................32 5.2.2. A Possible Application: Dual Airspace............................................................32 5.2.3. Temporal Granularity.......................................................................................33

6. DUAL AIRSPACE.......................................................................................................34 6.1. THE HIGHWAY ............................................................................................................ 34

6.1.1. Infrastructure ...................................................................................................34 6.1.2. Adaptability ......................................................................................................36 6.1.3. Traffic Management.........................................................................................36 6.1.4. Control Support Tools......................................................................................36 6.1.5. Human Factors Aspects ..................................................................................37

6.2. COEXISTENCE............................................................................................................ 39 6.2.1. Criteria .............................................................................................................39 6.2.2. Organisational Prerequisites ...........................................................................39 6.2.3. Coordination and Interaction ...........................................................................39 6.2.4. Human Factors Aspects ..................................................................................40

7. CONCLUSION ............................................................................................................42

LIST OF FIGURES Figure 1: The three pillars of air navigation....................................................................................... 1 Figure 2: The axis of the research agenda ....................................................................................... 2 Figure 3: The lower-level axis ........................................................................................................... 3


Project INO-1-AC-SHIF - EEC Note No. 16/05 ix

REFERENCES

[1] Guichard, L., Guibert, S., Hering, H., Nobel, J., Dohy, D., Grau, J-Y., Belahcène, K. 2004. Paradigm SHIFT Operational Concept Document, EEC Note No. 01/2005.

[2] C-ATM High Level Operational Concept., contract EC TREN /04/FP6AES/S07.29954/502911. February 2005.

[3] CDM (2003). Airport Collaborative Decision making Application Applications: Operational Concept Document. EUROCONTROL - EATMP Reference n° 030408-01, Edition n°1, February 2003.

[4] CENA-Evaluation d’ERATO 1997-1998 CENA/R98 842/ICC. Fevrier 1999.

[5] Gawinowski, G., Nobel, J., Grau, J.Y., Dohy, D., Guichard, L., Nicolaon, J.P. & Duong, V. (2003). Operational Concepts for SuperSector. Fifth USA/Europe seminar on ATM Research and Development. 23-27 June 2003, Budapest, Hungary.

[6] Grau, J.Y., Gawinowski, G., Guichard, L., Guibert, S, Nobel, J., Dohy, D., & Belhacene, K. (2004). SuperSector Experimental Results: Proof of Concept Assessment. 23rd Digital Avionics System Conference, October 24-28, 2004, Salt Lake City, Utah, USA.

[7] Zeghal, K. Hoffman, E. 2000. Delegation of separation assurance to aircraft towards a framework for analysing the different concepts and underlying principles. ICAO 2000 Congress.


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1. INTRODUCTION

The purpose of this document is to set out a research agenda on the various multidisciplinary subject areas (ATM expertise, human factors, systems engineering, mathematics, etc.) arising from the Paradigm SHIFT Concept.

The analysis of the current air transport system, conduced in the first part of the Paradigm Shift Project, introduces a new way of designing the air navigation infrastructure based on the concept of management by objective instead of by means.

It defines the foundation of an ATM system able to cope with traffic demand at the horizon of 2020 and beyond, while maintaining a very high target level of safety and supporting a sustainable air transport business development.

The project describes an operational concept based on three major points:

• considering the air navigation service providers as a part of the air transportation system, with efficiency issues addressed with a global approach of this composite system;

• increasing co-ordination between actors based on negotiated contracts and optimise resources by reducing uncertainty;

• achieving operational excellence thanks to a local adequacy of a tactical triangle: traffic demand, infrastructure and operations.

This concept required further theoretical, operational and sustainability analysis, to demonstrate its relevance and validity in the frame of safety, capacity and efficiency issues linked to the growth in air traffic in Europe after 2020. This is the aim of this document.

The descriptions in the various parts of this research agenda are designed to be explicit enough allowing participants outside the project to perform autonomous experimental studies.

The work presented here is the result of working meetings between the partners of the Paradigm SHIFT Project, launched in January 2004, within the Innovative (INO) Research Area (RA) at the EUROCONTROL Experimental Centre. The considerations are based on respect for the "three pillars of air navigation" (Figure 1), i.e. the consideration of working hypotheses which take account of the close links between airspace, traffic organisation and working methods.

Traffic

Airspace

CCAAPPAACCIITTYYSSAAFFEETTYY

Working Methods

Figure 1: The three pillars of air navigation


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The SHIFT Operational Concept Document (OCD) proposes two majors paradigms as the backbone for the shift of control paradigm from the current to the future:

• the contract of objective; • the dual airspace.

These two paradigms could be independent but could also be combined together because there is no contradiction in their mode of operations.

In order to establish an operational agenda centred on research areas, the two paradigms have been divided into different axes (Figure 2). This document is structured on the basis of these divisions.

The Contract of Objectives defines objectives applicable to flights and links ATM actors together through agreed interfaces. This Contract of Objectives is drafted during a negotiation phase involving all actors i.e. airlines, airports, ANSP, military units, etc. whereas individual objectives are assigned through the breakdown structure of the responsibilities locally at the level of the control centre.

We assume that local actors have the best view of how to optimize their organization. By doing so, at each local organization, there would be a decentralized ATM structure.

The objective assignment and negotiation can be performed as a collaborative decision-making process to establish the Operational Agreement.

The so-talked Operational Plan does not preclude any strong constraint on the agreed objectives, but allows a certain degree of tolerance. Disruptions are part of the ATM system. Putting constraints to insure safety and fluidity is necessary to manage the traffic. But over-constraining the objectives closes the door to the necessary flexibility to deal with uncertainty.

The notion of Target Windows is suggested here to define the intermediate objectives for a flight, where a target is associated with an interval called 4D-windows. These target windows are supposed to be the negotiation tool or the mean to achieve the Operational Agreement.

The paradigm of Dual Airspace introduces a small number of continental highways conveying long haul cruise traffic additionally to all-included sector-based traffic (district) as it is the case today. The purpose of this paradigm is to release the pressure on local air navigation services by separating the long-haul routes from the current routes. Long-haul routes could be assimilated to highways while short-haul (local) routes could be as main routes.

Figure 2: The axis of the research agenda



Each of these five elements will be subdivided into various lower-level research axis, as shown below (Figure 3).

Figure 3: The lower-level axis



2. THE CONTRACT OF OBJECTIVE

The contract of objective is a contract of results (aimed at achieving punctuality and efficiency while still, of course, respecting safety) associated with a flight including all actors involved for that flight. The contract of objective results from the operational plan, a process of negotiation and refinement involving all the actors mentioned above. The expected results are defined in the form of objectives for each actor (i.e. margins agreed and negotiated by the various actors) from off-block time (the moment when the aircraft disconnects from the departure gate) to in-block time, (it connects to the arrival gate).

The contract of objective strengthens the functional and operational link between the actors involved for any given flight, with the objective of improving overall system performance and productivity. It will change:

• the work of tactical control operators on the ground, by giving them an extra task by respecting the performance objectives assigned in the contract;

• the work of flight crews, and above all, relations between air and ground, by means of sharing responsibility with regards to respect for punctuality and financial criteria during the flight ( fuel burning, delays..);

• the relations between tactical control bodies on the ground and aircraft, by strengthening the flight's operational continuity.

2.1. THE WORK OF TACTICAL CONTROL OPERATORS ON THE GROUND

The main idea of the contract of objective is the addition of an extra task for the bodies responsible for tactical control of aircraft, namely respect the objectives assigned to each operator. These objectives are target windows defining in four dimensions the intervals within which aircraft must appear at entry points of the control unit and the intervals within which they must be transferred to the next control unit. The target windows are constructed on the basis of a strategic vision of safety and a tactical approach to performance. The controller's task, therefore, is twofold:

• to ensure separation between aircraft at tactical level; • to execute at tactical level the performance objectives contained in the aircrafts' contracts

of objective. The contract of objective is a commitment by the air navigation system vis-à-vis airlines and airports to respect performance criteria as a quid pro quo for constraints which may be applied to aircraft. Respecting the contract of objective, however, always comes second to safety. Safety remains the priority of control units. Adding this task will significantly alter the activities of operators in managing aircraft. This raises several questions:

• workload; • situational awareness; • human machine interfaces; • support systems and aids; • job satisfaction and interest.

2.1.1. Workload

The first question is relative to controller workload. In other words, will the addition of the tasks associated with compliance with the contract of objective's target windows allow tactical control operators to have enough time to continue to guarantee safety? This point deserves to be studied with care, taking into account the following issues: operator confidence, formalisation and industrialisation of working methods, satisfaction and fulfilment of human operators.



Workload must be studied in its entirety, in relation both to the safety level expected and attained and to the traffic load. The draft contract of objective should always be viewed from the perspective of increasing traffic loads. Tactical control operators must be able to apply the contract of objective when traffic loads are high as well as respecting aircraft separation criteria.

In order to come to a useful understanding of the concept of workload, this term deserves to be precisely defined in the context of the new working environment in order to establish assessment methods suited to the constraints of a process such as an innovative project, which is geared towards designing new concepts. This means taking into account cognitive and socio-organisational components of tactical control operators' work.

2.1.2. Situational Awareness

Although related to the concept of workload, situational awareness differs from it in the issues it raises. In the world of air navigation, the concept of situational awareness is most commonly assimilated to the "picture", frequently used by controllers. Since the roles and places of the various operators are not yet known in the context of SHIFT, it is preferable to retain the concept of situational awareness which, unlike the term "picture", is not limited solely to the notion of perceiving a radar image.

Situational awareness is defined as perceiving the environmental elements within a certain area of space-time, understanding their significance and projecting their current status into the near future. If a more "situated" and "ecological" view of cognition is incorporated, situational awareness is defined in relation not to its product but to its process. Situational awareness can thus be considered as the operator's ability to know which environmental indicators and requirements allow him/her to perform actions suited to the criteria for the performance of the task. Changing the tasks of tactical control operators means introducing into their activities other challenges and, consequently, a change in their situational awareness at the level of both product and process.

As regards to the product of situational awareness, this raises the question of which information is relevant to the task and the issue of multiplicity of information. The "cognitive" objects to which situational awareness relates may not only differ amongst themselves but also change in the way they are treated at the level of their granularity (the principle of data fusion). The object of a study on situational awareness at this level is to set the limits the field of situational awareness and highlight changes in relation to what exists today. Like for the workload, the issue of situational awareness can only be considered by developing a qualitative and/or quantitative situational awareness assessment methodology.

As regards to the process of situational awareness, the question raises changes in the skills of tactical control operators. The introduction of a new task, one which has a high priority because it represents a commitment on the part of the air navigation system, will modify information-processing priority rules. It is therefore important to study the notion of performance and decision-making mechanisms under great time pressure. The theoretical current of natural decision-making offers decision-making models elaborated in various occupational contexts. These provide a possible starting point for any study on tactical control operators. Risk management occurs at the same time as decision-making and is an entirely separate issue whose significance becomes clear in the context of the contract of objective. The contract of objective introduces different performance criteria and thus different risks which will come directly into conflict with safety objectives. Even though priorities are set by means of regulations, operators will find themselves faced with conflicts of interest which will give rise to different perceptions and methods of managing risks (safety risks vs. operational risks).



A better knowledge of these changes should enable to model the process of situational awareness so that conclusions can be drawn from it in terms of learning and training.

2.1.3. Human-Machine Interfaces

Requirements with regard to information and instructions will increase at the level of tactical control operators, both because there will be more elements to take into consideration when managing an aircraft (respect for the performance criteria defined within the framework of the contract of objective's target windows).

To look into these developments, and to deal with traffic increase, an in-depth study should be performed on the development of control position interfaces. Today's interfaces make little or no use of alternative technologies such as voice command, speech synthesis, touch screens, helmet sights and/or displays, sound spatialisation and three-dimensional vision, to name only those which are starting to become operational in the aeronautical world. The aim is not to conduct "showroom" studies but rather to put in place a design process based on operational requirements. Potential use of these technologies is important in order to transform information exchanges between humans and machines. Either on an individual basis or on the basis of multimodality, technology will make it possible to increase human-machine exchanges both quantitatively and qualitatively.

Multimodality is the term used to describe the simultaneous or combined use of several means to interact between the human and the machine. The means of interaction may be defined not only in relation to the five human senses but also in relation to the communication aid. Combining vision and hearing (for example, by means of a radar screen associated with sound, whether spatialised or not) is a type of multimodality, just as the combination of a radar screen and a helmet sight is a type of multimodality for the visual modality.

The great benefit of alternative technologies is that they could bring more natural dialogue solutions which are not only better suited to the constraints of the job but which also better respect intra- and inter-individual variability. They also enable aids which will fit in as well as possible with the activities of operators and which will take into account the numerous interruptions which characterise complex tasks such as tactical aircraft management.

Through interfaces, machines should become a continuation of human cognitive processes. For this reason, dialogues which add to the operator's workload must be designed with the closest possible attention to performance. Performance is located at the level, not only of the means and modalities of interaction, but also in their information content (lexis and syntax of messages). Technology all too often opens up fresh avenues which are blocked either by operational requirements or by incompatibility with the demands of the task. Technological limitations are thus ignored or underestimated. The only advisable course is to develop interfaces in such a way as to bring together technological challenges and operational requirements.

Future concepts for managing and controlling traffic are increasingly collective in nature. Accordingly, the system must become part of this collective whole by means of a more integrated human-machine interface. Thus the system must both receive information and provide it to the human operators. This is relatively easy to achieve in the context of a relationship between a single human and a single machine and/or a single machine and a single human (stripless concepts fall under this heading). In the context of a human collective, the place of the machine is more difficult to define, all the more so when the collective is distributed: how can the machine be integrated into collective negotiation and decision-making processes whose status is similar to that of a relationship between a man and a machine? The task becomes even more complex if a number of machines, also distributed, are to participate in the collective work. This causes real problems in terms of formalisation of communications and declarations of intent between the various actors.



2.1.4. Support Systems and Aids

Introducing the contract of objective into tactical aircraft management raises the question of the aids to be provided to tactical control operators. Much current research aims at automating some of the controller's functions or tasks. The most difficult tasks to automate are those relating to comprehension and decision-making, because it is here that the greatest degree of uncertainty is encountered. It is, however, easier to propose systems which present or synthesise information and which execute actions or verify that they have been properly executed (projects such as Dynastrip fall under this heading, proposing as they do a formalised way of presenting information - namely, the time line for flight plan aircraft route data - which is closer to the controllers' mental representations).

The development of comprehension and decision-making aids for operators raises two questions of particular importance to air traffic control:

• The complementarity between the operator and the aid system; • The responsibility for the task.

Complementarity between the operator and the aid system is emphasised by all authors in order to underline the fact that an aid system's performance is appraised on the basis of the level of complementarity between it and its user. Complementarity is based on complementary modelling of human-machine relations. This means that the machine must complement human operations. The term, used to describe how these aid systems must be, is "human-like". The advantage of this is also that the operator can at any time resume control over what the machine is doing and replace it. Complementarity also presupposes dialogues which will consume time and resources. It is here that the limitations of comprehension and decision-making aid systems in air traffic control become obvious, in the light of constraints imposed on operators by the task in terms of time and mobilisation of cognitive resources. There can be no doubt, however, that this work on the delegation of tasks to aids must be continued in the context of the contract of objective, in order to provide solutions to the problems of workload and situational awareness, which will not simply disappear.

The question of responsibility is connected to complementarity and is just as important. Traditionally considered as human, it requires human operators to remain in the functional loop of any aid system.

Another way of considering aid for operators, one which must also represent an avenue of development within the framework of the contract of objective, could be of assisting cognitive functions rather than delegating tasks. Human operators are powerful information-processing machines, but their tools, i.e. their cognitive functions, have certain limitations. The purpose of assistance is not to replace humans by an automated system with regard to this function, but rather to provide them with support which will help them to manage their functions and cognitive resources to the best of their ability.

2.1.5. Job Transition

The work of tactical control operators in the future will be different from today. The trend will probably be towards industrialisation of working methods which will restrict the operators' scope of action and thus freedom. Thinking out a new navigation system also involves thinking about the system transition and thus about how acceptable the changes in their work will be to the operators. The contract of objective brings new challenges for tactical control operators. It will require to look into the acceptability and interest of these tasks to operators. The research to be undertaken in this area falls within the domain of psycho-sociology and relates to the subject area of the transformation of labour.



Research skills

Human factors Design ergonomics Human-centred design Organisational sociology

2.2. THE WORK OF FLIGHT CREWS

The contract of objective will also change the task of flight crews. Under the current model, there is a clear separation between ground and air in relation to aircraft separation and flight efficiency. The ground controller is responsible for aircraft separation, although this is not quite true anymore since the introduction of TCAS in the cockpit. The flight crew is responsible for flight safety and efficiency (punctuality and cost-efficiency). In this scenario, ground controllers respond to the requests of flight crew or try to operate efficiently on the basis of an entirely personal system and without specialised tools. The new concepts associated with air traffic control (ASAS) and the contract of objective) tend to involve ground and air actors on a combined basis with separation and efficiency tasks. Questions relating to the sharing of the actors' tasks and responsibility for aircraft separation will naturally be raised in the same way when tasks will be shared between the ground and the aircraft in relation to flight efficiency.

The problems underlying the sharing of tasks and responsibility in the area of efficiency are of three kinds:

• changes in the tasks of flight crews, which might tend towards reduced involvement in efficiency management in the interests of greater involvement in safety and separation;

• task sharing between ground and air, which might question the principles of responsibilities and the way they are distributed today;

• technological support for the exchange and sharing of all data relating to the execution of tasks shared between ground and air.

2.2.1. The Tasks of Flight Crews

Are these new additional tasks feasible? Tasks transferred to the aircraft are often thought of as if they were being performed on the ground, whereas in reality the flight crew operates in a dynamic environment in which it has a direct impact. Unlike ground controllers, the flight crew interacts directly with the environment and manages the stresses associated with the flight. Its availability is not at all what it appears from the ground. For the flight crew, relations with the ground are just one task among others, albeit an important one. As a consequence, any delegation or sharing of tasks must be considered in the context of a global approach to the flight crew's tasks, with all its constraints. In future, for example, with the arrival of very large aircraft, flight-deck management tasks of crews are likely to become more and more time consuming.

With regards to the contract of objective, what is considered is more of delegation of tasks (punctuality and cost-efficiency) currently performed by the flight crew to the ground The nature of this delegation requires a detailed study in order to achieve a true synergy between ground and air (common intentions achieved through an action plan accepted by all the actors) and leave the flight crew in the information and decision-making loop, even giving it the capability to detect and correct errors made on the ground, if needed, in order to ensure safety. Behind these delegation process, one will find ergonomic problems traditionally aired in relation to complex continuous process control situations.



Situational awareness, workload, interfaces and aid systems are therefore all areas which will have to be dealt with in the process of defining and designing tasks which are transferred and shared between tactical control operators and flight crews.

2.2.2. From Liability to Shared Liability?

Over and above task-sharing, the question naturally being raised is the operators' criminal liability vis-à-vis safety. This is no less important for tactical control operators than it is for flight crew members. It is dealt with here in the section on flight crew more by arbitrary choice than for any other given reason.

In the context of criminal liability, to what extent can such liability be shared or ignored by an operator who might nevertheless have a similar "overview" of the traffic? These questions require not only a suitable legal framework but also that future tasks of air transport actors should be taken into account in their entirety, both on the ground and on board aircraft. From a legal point of view, criminal liability is personal and individual. It cannot be collective. However, since several operators are required to interact in the same work space, it is possible to use the term “joint liability”. However, everyone is responsible for its own actions and therefore for its own mistakes, in proportion to the mistake made within the group. Two, three or four operators may thus be held liable if it is proved that they each made a mistake. This means that the sharing of tasks between operators must be as clear as possible (who does what). Further, having access to another operator’s data may entail joint liability if it is established that due diligence was not shown, taking into account the nature of the mission or the operator’s duties, areas of responsibility but also available resources.

In order to illustrate the problems raised by the contract of objective in terms of liability, take as an example the following scenario for ground-air relations: flight crews are no longer the only persons responsible for insuring on time arrival at the destination. They cannot question the contract of objective once it has been accepted by all the partners. As long as the flight takes place within the envelope defined in the contract, it is the controller who gives orders to flight crews regarding safety and navigation. It goes without saying that under no circumstances, controllers can pilot the aircraft. All orders from controllers are submitted for approval to and executed by the flight crew. This also means that the flight crew has on board all aircraft information, giving it the "position" of the aircraft in the contract as well as an overview of the traffic.

If the contract of objective is to be accepted by all, their liability must be clearly defined in it. However current criminal-law frameworks might have an impact on the liability involved:

• some liability is clearly established in the existing legal framework; • the legal framework may contradict the liability of task sharing and may need to be

adapted to some extend in specific cases. Can the various international legislations be standardised at a worldwide level?

2.2.3. Technological Support for Data Exchange and Sharing Between Ground and Air

One of the important points developed within the framework of Paradigm SHIFT is the transparency and sharing of the most important information by all participants. This applies, of course, to ground/air interaction.

Although this aspect has already been studied with even initial operational prototypes, a more global study on the "uniqueness" of the data implemented by controllers, flight crews and all actors, in conjunction with the conclusions of studies relating to the choice of data (see 3.2.2.1), might allow a unified context to be defined.



Datalinks will very probably have a major role to play: they will make it possible to study or develop services which allow the provision for not only shared situational awareness for ground and air operators but also for support tools. Examples of services such as these, on which studies have already been conducted, are pre-departure clearance (PDC), flight plan consistency (FLIPCY) and the Traffic Information Service (TIS).

Research skills

Human factors Legal aspects Human-centred design Systems engineering

2.3. OPERATIONAL CONTINUITY

The main aims of the contract of objective are aircraft punctuality and a high quality of service provided by the air transport system to airlines and airports. However, this contract also represents a tool for providing operational continuity both among the various air navigation actors and between air navigation actors and aircraft, or at least the aircraft covered by a given contract of objective

Operational continuity consists in the creation of a common working framework for all operators (ATCOs and flight crew). Even though they all have different missions (aerodrome control: airport movements, take-off, landing; approach control: arrival and departure; en-route control) and do function differently. European airspace is a mix of countries and cultures which has to work together. The contract of objective and the operational plan respect the identity and autonomy of all involved but introduce operational continuity with a view to making the whole system more efficient. It would appear more and more important to make different operational control modes coexist, each mode being the best suited to given traffic and airspace criteria.

Operational continuity must be considered at three levels: • the interface between tactical control operators; • the interface between flight crew and tactical control operators; • the operational responsibility.

2.3.1. The Interface Between Tactical Control Operators

Tactical control operators ensure that safety is geographically continuous throughout an aircraft's flight. To this end, each of these operators manages and controls aircraft in the airspace for which he or she is responsible, but also ensures that the crossing of aircraft into and out of adjacent volumes of airspace is coordinated.

For each aircraft, the contract of objective sets the operational framework within each control operator must manage. It incorporates the interfaces with adjacent control units, i.e. the target windows. With regard to coordination between sectors as it is done today, however, it is clear that the transfer of aircraft between two sectors is not limited solely to a space transfer. The coordination is much more complex. It draws on a process of anticipation, as much for the sector which the flight is leaving as for the sector which it is entering. The sector which the flight is leaving prepares the trafficof the following sector and only transfers it at a precise given moment. The sector which the flight is entering analyses the traffic well before it comes under its responsibility, in order to anticipate how to manage it. In both cases, transfer windows are far from set. They vary in accordance with the control operator's strategies, the density and nature of the traffic.



With contracts of objective, the same question of anticipation arises. Working methods between adjacent control units thus deserve special attention in order to take into account the anticipatory dimension of the task of coordination. This may call for specific information in order to ensure that control is both safe and efficient.

Heterogeneous airspace, or the possibility of creating a European airspace made of different operating modes for managing and controlling aircraft, appears to be the solution to the problem of optimising ATM performance in the future. It would ensure the best management of the compromise between the service provided and the constraints on aircraft, on the basis of the traffic density in the given airspace and the ATM resources available. The possibility can thus be considered of an aircraft's crossing a portion of airspace comprising different operating modes. One might list operating modes on a scale running from the "least constrained and lowest in capacity" to the "most constrained but also highest in capacity" in the following order: free flight, free routes, direct routes, standard routes and highways. The management and control of each aircraft for each operating mode are specific in terms of the working methods, tools and sharing of responsibility between ground and air. Each operating mode must therefore be the subject of specialised studies. Beyond defining what happens within each operating mode, however, the operational continuity of the aircraft between the various operating modes must also be considered. There is no doubt that the contract of objective will build this continuity, but the transitions between operating modes must also be looked upon in terms of their consequences on the contract of objective and its use by both tactical control operators and flight crews.

The transitions which will involve coordination, as described in the previous paragraph, are real interfaces which must be studied from now on within the framework of defining the contract of objective. For example, how is one to consider the transition between a free-flight operational mode, dependent on the flight crew's being almost entirely autonomous, and a more traditional control method, with routes and separation ensured by tactical control operators on the ground? It is difficult to answer this question today, since the various possible operating modes are unknown, as are the possible characteristics of some of these operating modes (free flight or free routes, for example).

What would be the consequences of these transitions on the actual content of the contract of objective? It should comprise various components, depending on which operational mode one is in. Similarly, changing from one operational mode to an other will have consequences on how the target windows are defined, prepared and how operational continuity is guaranteed, by means of coordination between the various operators. For example, an answer must be found to the question of how an aircraft is to change from free-flight mode, in which routes are not defined but rather left to the discretion of the flight crew, which also ensures separation between aircraft, to a standard route mode in which the aircraft is once again on "tracks" and is controlled by a centralised system on the ground.

2.3.2. The Interface Between Flight Crew and Tactical Control Actors

The interface between flight crew and tactical control actors is essential for guaranteeing the operational continuity and thus the efficiency of flights. The sharing of responsibilities for safety and efficiency between the aircraft and control together with changes in these responsibilities in accordance with the operating mode for managing and controlling traffic raise a certain number of questions on the sharing of information between the aircraft and the controllers.



This question is mentioned in the "aircraft" part of the contract of objective with regard to all aspects of the flight crew's work and the consequences for human-machine interfaces. It is nevertheless important to enhance it with a collective view of the work in order to better grasp all the issues involved in this change in the work.

To share responsibilities in order to carry out a common task is to be part of a collective approach to work. This has only a meaning if it is accepted that collective work is the best response to the question of how to meet the performance and safety objectives which have been defined. This also means that everyone has a role to play, that roles are complementary and that they must also be partially redundant vis-à-vis the task's central aspects. This is possible only if the various operators work in accordance with a common view of the situation in which they are involved. The term used in the field of human factors is "team situational awareness" or, in this particular case, "distributed situational awareness", because the operators are not in the same physical place.

"Team situational awareness" refers to the mental representation of a situation which must be shared by the operators involved in that situation. Team situational awareness is not the sum of the situational awareness of each individual. It is the situational awareness which all the operators must at least share in order for each of them to be able to perform their task correctly and interact effectively with the other operators. Team situational awareness is important because it makes it possible to share understandings of the context and the intentions of others, and thus to anticipate those elements of others' work which relate to one's own.

Studying it is important because it will make it possible better to specify everyone's tasks and responsibilities. It will have repercussions on the way in which human-machine interfaces are understood, working procedures considered and, consequently, operators trained. Lastly, particular attention will have to be paid to the fact that the team referred to is a "transitory" team. The team is formed when the aircraft enters each control unit and disbands when the aircraft is transferred to the next unit. The operators do not know each other and have never worked together before. All these features exist today, of course, but they deserve even closer attention in future because tasks and responsibilities will be shared to a greater extent.

2.3.3. Operational Responsibility

The responsibility of ATC operators is traditionally looked upon in terms of safety. With the contract of objective, the notion of operational responsibility is introduced. It is possible to speak of the partners' operational responsibility for everything associated with the execution and review of the contract of objective.

The reviewing of the contract of objective during the flight has serious consequences for the partners. The reasons for reviewing must be known so that they can be the subject of possible compensation among the partners. This operational responsibility will deserve to be studied in the framework of the definition of roles and tasks for each partner at the same time as it is incorporated into the global process of air navigation operations and relations between the partners.

Research skills

Human factors Legal aspects Human-centred design



3. THE OPERATIONAL PLAN

The operational plan represents the process of negotiation involving all the actors, which leads to the refinement of the initial demand.

The feasibility of this mechanism, which is put in place to ensure cooperation and common awareness of each participant's constraints in the interests of establishing the best possible compromise, needs to be assessed in very different areas, both basic and applied. The main axis of this research are presented in this chapter.

3.1. THE ACTORS

In the terminology of the SHIFT Project, an actor is defined as a participant in the negotiation and conclusion of agreements within the framework of the operational plan. He has a responsibility towards the other actors for the results of the contracts of objective. He will therefore be responsible for the work to be done by the operators for which he is responsible.

It could, for example, be an airport (such as Aéroport de Paris), an airline (such as United Airlines) or an ANSP (such as SkyGuide).

The actors manage demand and resources. They will be involved in an environment which might be regarded as a financial market in which attempts will be made to reconcile demand and resources as effectively as possible. In order to ensure that an agreement is reached, it is therefore vital to assess which form of organisation is optimal, or as close to optimal as possible, and will make the operational plan to function smoothly with maximum efficiency.

Within the framework of the Single European Sky, the concept of the operational plan introduces constraints which are intrinsically linked to its collaborative aspects, to the balanced consideration of the constraints of all participants and to the desire to manage traffic at continental level. It may also, however, make it possible to initiate a study dealing globally with the roles and organisation of the air transport chain.

Such an assessment could be conducted on the basis of various approaches, which may sometimes be complementary and even make it possible to make a decision on the alternatives proposed by other studies. Those listed here represent only an initial consideration:

• modelling; • functional; • organisational; • political; • environmental.

It might seem surprising that this list does not contain a financial axis. This question will have to be tackled. The actor's very nature, however, i.e. its being a responsible and autonomous body, makes a generic approach to the problem difficult. Air France's financial model, for example, is very different from that of a low-cost airline such as Ryanair.

Such studies are necessary, of course, but will more probably be directly integrated into the measures linked to the functional approach (see 3.1.2) implemented by each family of actors, or within the framework of the decision-making aid in the operational plan when the alternatives are assessed (see 3.2.3).



3.1.1. Modelling

The modelling referred to here is more a mathematical than an operational approach.

The operational plan may be compared to a market which would manage supply (the various resources) and demand, but which also has a collaborative decision-making (CDM) framework

This purely "theoretical" approach, which introduces various types of models and interaction between actors, may lead to conclusions at structural level such as, for example, the maximum number of actors required to ensure optimal functioning.

Apart from the inherent interest of these studies, the alternatives and responses proposed could be compared with the results of studies associated with the functional axis and thus orient the alternatives produced by it, if necessary.

3.1.2. Functional Approach

The operational plan is a collaborative and a transparent mechanism. It must prepare the ground for a consensus shared by all the actors. However, a negotiating mechanism is always difficult to put in place, and its smooth functioning is most frequently linked to a judicious choice of participants in the process.

If this is approached from a purely operational perspective, one might wonder who the actors will be and what they will represent in ensuring the optimal functioning of the operational plan in terms of the number of participants, their ability to react and their decision-making capacity.

3.1.2.1. Airports

One of the scarce resources is airport capacity. It can be defined as a combination of the capacity of airport service providers to perform operations on the ground and the available runway throughput. Ground operations are currently the airport's responsibility, while everything which happens after the aircraft disconnects from the terminal is the responsibility of ATC.

Is it conceivable to regroup these two components within the same body to produce an "airport" actor? Does it improve the negotiation mechanism?

Considering it from a different angle, would regrouping on a geographical basis results in a reduction in the number of potential actors.

Would regrouping regional airports in the vicinity of a major airport contribute to the improvement of the process?

What geographical, traffic or financial conditions allow a decision to be made on the formation of such a body?

Does such regrouping have any impact on the structure and management of approach control?



3.1.2.2. Airlines

Some years ago, major airlines started on a process of forming alliances, mainly for profit reasons.

In this context, would the operational plan be more effective if the actor participating in the process represented an alliance, i.e. a group of airlines?

Could one consider demanding that all airlines form a consortia and be represented?

Could IATA represent airlines within the framework of the operational plan?

3.1.2.3. ANSPs

First of all, it is useful to define what the ANSP represents in this context. It is an organisation which provides air traffic control. Whether this body is private or public is not an issue in this document, even if the economical aspect varies. The aim here is rather to consider what can most usefully be put in place within the framework of the operational plan.

Should one be dealing with one control centre or with a group of control centres?

If a group of centres, what criteria will govern this group?

Will these groups be national or international?

3.1.2.4. Moderator

The operational plan is inconceivable without a supervisory body which will play the role of arbitrator (moderator) in the event of a resolution's being required in order to reach an agreement, but also that of guarantor of the operational plan's smooth functioning and of the availability and safety of data. The moderator should also be in a position to assess the performance of the system as a whole but also that of each actor, thus spearheading a continual process of improvement. It could be seen as a Regulator. It will therefore require the means to put in place and monitor a mechanism of actor certification and/or assessment. A study will have to be conducted to look into the framework and tools required for this mandate.

3.1.2.5. Military component

The participation of military bodies should be studied with great care. While it is now acknowledged that this participation should take place as early as possible in the process of bringing demand and resources into line, the question of how to introduce it remains difficult.

There is a number of military components. This is clear from a consideration of the associated activities, which may be divided into three areas:

• One or more airlines. Like civil airlines, the military has a fleet to manage and a demand to express in terms of flights and even rotations.

• Airport(s). This is also a complex area to manage, since the airport(s) in question may be either purely military or mixed (i.e. handling both civil and military traffic).

• ANSP(s). In most cases, even though liaison/transport flights can be delegated to civil ATC, there are still tactical flights which remain the responsibility of military ATC.



A study should be conducted to find the optimal compromise between these various options:

Is "total" integration of the military component into the civil domain realistic or not?

How can the expectations and interests of this component be taken into consideration?

Should it be dealt with at national or European level?

3.1.3. "Political" Approach

There is increasing openness to competition and/or privatisation in the field of air traffic control.

Will this trend and the arrangements for applying it have consequences for the definition of the actors?

Will a legal or legislative framework have to be defined for this process in order to allow the operational plan to function smoothly?

3.1.4. Environmental Approach

The environmental aspect is an increasingly high priority in decisions relating to air transport.

Studies of air and noise pollution around airports may influence future choices. What impact will the various chosen options (for example, encouraging the development of regional airports or concentrating on major ones) have on the definition of the actors?

From a more global perspective, moreover, recent studies suggest that commercial aviation is responsible for 2.5% of world carbon dioxide emissions as a result of human activity.1 These measurements are most commonly expressed in "grammes of CO2 per passenger-kilometre". The optimal configuration for limiting such pollution is a long-haul flight performed by a new aircraft with a high load factor. Charter flights (with no business class) with a high load factor are therefore characterised by better "energy efficiency". Short-haul flights result in higher consumption and therefore higher relative emissions, as a result of the relative importance of take-off and their lower cruising altitude.

It might therefore be useful to perform a study combining these indicators with the operational aspects in order to define optimal demand with regard to user and environmental requirements.

A combined study of this nature could also be extremely useful in guiding the functional approach mentioned in 3.1.2. It could also be incorporated into and influence the autonomous ANSP design phase (see 5.1).

An approach allowing financial and environmental issues to be associated as early as possible in the design and definition of the operational plan, and favouring not the objectives (as outlined above) but the means (the "polluter pays" premise) could also be considered.

3.1.5. Organisational Approach

The implementation of the operational plan and the definition of its actors may lead to a new system for apportioning responsibility for air traffic control, in particular by establishing supranational bodies.

1 "Transport aérien de passagers et effet de serre", Les données de l'environnement , 97 (Institut Français de l’Environnement ).



This would lead to an assessment, both political and legal, of the feasibility and durability of these bodies.

All the implications of establishing such bodies should therefore be studied and a politico-legal framework defined.

Research skills

Air transport finance and management Modelling Operations The mathematics of decision-making Legal aspects The environment Political issues

3.2. THE PROCESS

The operational plan represents not only a space for cooperation but also a space for transparency vis-à-vis all the actors, which allows optimised planning in terms of efficiency and performance.

The process must therefore be accepted and supported by everyone. It is therefore vital to provide all with the necessary data and the means of processing them.

A study must therefore be initiated to look into which data needs to be shared (operationally relevant) and how to reach a common understanding of data presentation.

3.2.1. Negotiation Protocol

The negotiation of the operational plan involves the participation of all air transport actors. It affects all the target windows which appear at strategic level: take-offs, landings, transitions. The target windows are inherently valuable because they entail the notion of a guarantee. This information enhancement opens many perspectives at the level of air transport as a whole.

Given the number of participants, the various kind of their motivations and the complexity of the operational constraints, it is hopeless to attempt to reach any kind of "global optimum". The selected negotiation protocol must, however, do the following:

• Constrain operations to good effect. The constraints specified by the target windows are traffic regulation tools which require that an effort to respect punctuality should be made upstream in order to protect the process downstream.

• Result in an agreement which satisfies all parties. Since the principle behind the target window is to create value, in the sense that it commercialises punctuality, the rewards enabling progress to be made which otherwise would be difficult for a single actor can take various forms.

• Be fair. The interests of society must be taken into consideration within the model, but the model should not favour one commercial policy over another.



• Be stable. This feature, which can damage from the quality of an agreement, is nonetheless essential. It must not be possible to hastily review decisions taken at a given moment. The reason is that this information could contribute to the ANSPs' design decisions (a costly process) or provide a basis for commercial agreements entered into by airlines.

• Allow subsidiary. Actors make decisions autonomously.(decentralised decision-making).. The negotiation process must make it possible to banish discrepancies but also have access to a central body, if needed.

• Be flexible. The process shouldn’t be too rigid otherwise it becomes counter productive. It shall also be able to integrate some late requests, resulting of unplanned events.

Many courses of action may be considered in order to reach such an agreement: bilateral agreements, open market, auctions, a decomposition/coordination approach. The design of the operational plan set the hypothesis of an iterative process, in which the decentralised design phases (more and more detailed description of traffic) alternated with phases of reconciliation. This ensures the traffic continuity by propagating the constraints of the most constrained systems to the least constrained ones.

Once the procedure becomes known, some actors will want to guard themselves from the financial risks it entails, which may lead to the introduction of related products such as insurance, tenders, options, etc.

Research skills

ATC Operations The mathematics of decision-making: mathematical economics game theory team theory decomposition/coordination of complex systems

3.2.2. Data Models

The area for cooperation will require the definition of a common data model in order to allow everyone to take the right decisions on the basis of the various situations encountered.

It will have to be decided at an early stage, therefore, which data are essential to the smooth functioning of the operational plan.

Since data is accessible to all, of course, all the actors must check that they will be in a position to share them. Some of data might be confidential for the actors and might be a risk of disclosing a commercial strategy. Therefore, the possible impact on competition might need to be assessed.



3.2.2.1. Choice of source

In a collaborative environment, a given piece of data can be accessed by everyone. It may, however, be provided by various means.

The choice of the most suitable source must be made not only for information relating to the flight's "reality" but also for the entire downstream phase.

With regard to flight data, for example, the source may be a single sensor (a radar) but also a data fusion system (GPS) supplied by a number of sensors which may or may not be of the same type.

This choice may also, however, be made on the basis of the level of confidence/availability, if several devices provide the information simultaneously. It may also lead to rules or, even better, to "complex" weighting mechanisms/confidence indicators for the various sources available.

Data which might be described as "pre-flight" are more closely related to information systems which are most commonly supplied with information by a human actor. In this case, the choice will no longer be guided by quality and/or precision relating to a device but rather by which actor will be in the best position to provide reliable and relevant information. With regard to the off-block time, for example, the airport would appear to be the most reliable actor.

One might also consider a new use for the available data. Could the system be enhanced to improve the quality of predictions regarding the impact of disruption on planning? Meteorological information held in the airborne system could make it possible to improve the quality of assessments made on the ground by incorporating data of a more microscopic nature. These data could be exchanged by means of ground/air links (datalink, for example).

A single piece of data, however, can have various names/acronyms, various interpretations or various units, depending on the participant.

A study will therefore needed to be performed allowing all the actors to reach a common view of what the piece of data represents in connection with the choice of source.

3.2.2.2. Granularity of presentation

One of the major principles referred to in SHIFT, in addition to the transparency of the process and thus of the data associated with it, is the evolutivity of the data's granularity during the different stages of the process.

The operational plan represents a refinement mechanism. This mechanism is, however, continuous and parallel. At one given time, several stages of the operational plan may coexist: an initial stage between airlines and airports; a set of final negotiations of the Operational Agreement; and a set of renegotiations. The data model must make it possible to support this.

As a consequence, the model would have to ensure:

• That all participants can view ad hoc information in accordance with the current stage. An airline which is to access the operational plan information during the ANSPs' design phase, for example, must not be able to view the potential alternative flight paths under consideration. Once an ANSP has "published" these alternatives, on the other hand, the same airline can access them transparently (i.e. without manipulation on its part).



• That information can be enhanced asynchronously and viewed only by specific actors. In the above example, the ANSPs will be able to put in place alternative flight paths and amend all of them throughout their preparation phase, while the other actors will have no access to them until they are "published".

• That there is functional continuity with the operational phase represented by the contract of objective. It is conceivable, even though transparency is mandatory within the framework of the operational plan, that some information contained in the data model will be irrelevant to an actor or family of actors. This information may, for example, come from the tactical level and guide the strategist's choices. This information will not be contained in the contract of objective but may allow the actor to organise itself at tactical level and thus ensure the continuity of the flight within its area of responsibility. This information must therefore be available to the dissemination mechanism (see 3.2.4).

3.2.2.3. Coordination of the actors

As mentioned several times in this document, the operational plan can be compared to a market.

Some studies are starting to mention a "commercial approach" to slot allocation.2

This type of approach makes clear the need to introduce coordination between the actors in order to ensure that the market functions smoothly.

For stock markets, for example, models already exist which make it possible to describe how the various actors function and interact. By taking advantage of experience already acquired in other fields, it might be useful to study whether these models would make it possible to model the context of the operational plan and put in place the mechanisms required if it is to be viable.

3.2.3. Decision-Making Aids

The operational plan represents an iterative refinement mechanism. At various stages in this process, therefore, the actors will have to choose on the basis of certain alternatives to reach a consensus. These alternatives will have impact on operation’ costs of the various actors and a model or calculation methods will be needed to assess the costs incurred by each alternative. Naturally, these models will be differentiated on the basis, at the very least, of the type of actor (airport, airline or ANSP) being addressed.

As the operational plan progresses, the flow of data and related information increases. It requires to study the mechanisms which make it possible to develop capacities and thus remain in line with resources as much as possible. For example, in the case of airport capacities, how can a buffer mechanism be put in place which makes it possible to manage late demand without disrupting existing plans, and thus to avoid the "first-come, first-served" syndrome?

Further, it is important for this study to tie in with the work which is done in the research area relating to the target windows (see 4.1), the aim of which is to define the decision-making process vis-à-vis one of these windows.

2 Commercial slot allocation mechanisms in the context of a further revision of Council Regulation (EEC) 95/93 on common rules for the allocation of slots at Community airports, Commission of the European Communities, September 2004.



3.2.4. Dissemination of the Contract of Objective

The contract of objective materialize for a given flight the whole process of refinement (i.e. the operational plan).

The appropriate notification deadline before an aircraft's effective off-block time must be defined with the agreement of all those involved.

The dissemination mechanism must also be considered with all involved in order to define the best approach:

• Will it be triggered synchronously for all participants, each of them thereafter being responsible for whether or not they make the information available to their operators immediately?

or

• Will it follow time deadlines in accordance with the progress of the flight?

• Will it distribute the whole of the contract of objective, leaving it to each participant to "extract" the information relating to it?

or

• Will it distribute to each participant only the necessary and sufficient information relevant to it?

• Will it take into account any available enhanced information associated with the contract of objective?

or

• Will it leave each participant to distribute this information to its own operators?

3.2.5. Renegotiation

Renegotiation is related to an inability of one or several of the actors to meet the objectives set in the contract of objective.

Even if this involves only one aircraft, the consequences for current traffic and planning may be very significant.

This renegotiation must thus take place at a strategic level in order to provide a global approach to the problem and thereby attempt to curb or at least the "snowball effect" on planned and current flights.

Putting this mechanism in place is thus vital for the system, because reactivity and the appropriateness of the choices made are essential factors in the success of the operational plan. A structure and a mechanism must therefore be defined which will make it possible gradually to involve the appropriate actors in the resolution of the "crisis" situation.

Analysing the occurrences and situations which have led the renegotiation process, moreover, could make it possible to refine and adjust the various parameters leading to the definition of the target windows.



3.2.5.1. Organisation of the renegotiation committee

The organisation of the renegotiation cell must allow a rapid decision-making process and the operational relevance of the resolution choices at continental level.

The optimal size of this cell should be studied accordingly, i.e. not only the number of participants to be incorporated into it but also the representation of the various actors and the best professional profile for these participants. Should they, for example, be hands-on operational staff, managers or decision-makers?

Should this committee be a specific cell, or a part of the Operational Plan ?

Should this committee involved all the actors or only those who are affected by the situation occurred?

It will also be important to define the appropriate reactive process for allowing these participants to resolve these problems. At the same time, "final" decision mechanisms must also be defined in order to avoid blockages.

3.2.5.2. Impact assessment mechanism

As said before, reactivity is the key for the success of the renegotiation process and will limit the effects of chain reactions on planning.

The assessment mechanisms and tools allowing them to evaluate and select the various alternatives and their impact on the traffic will therefore have to be made available to all participants in this renegotiation group.

A study on "what if"-type mechanisms and tools will be undertaken in relation to airspace in its continental dimension.

These mechanisms/tools will have to take account of issues in the domain of:

• traffic flow; • the logistical potential of airport operations, or ANSP; • and kerosene consumption from the point of view of safety (i.e. does the aircraft have

enough fuel for this alternative?),

but also of financial (diverting a flight to another airport, for example, incurs specific costs for the airline) and/or the environment.

Research skills

Systems engineering Data management Modelling, particularly of markets ATC Operations Calculation of costs Environment



3.3. INFRASTRUCTURE

The availability of a significant flow of data, accessible to a large number of geographically dispersed participants with different profiles, must be supported by an effective, reliable and safe infrastructure.

The optimum architectures must therefore be studied from the point of view not only of communication but also of the information system and interoperability.

3.3.1. Network Architecture

The large number and heterogeneous nature of the participants which need to be interconnected (for example airports, airlines and meteorological installations), not to mention aspects relating to mobility (for example aircraft), mean that an assessment is required of what infrastructure is capable of satisfying the demands of continental, if not worldwide, network availability, in terms of technology (for example ATN and IPV6) but also of the network's feasibility (for example the volume of data) and topology.

As mentioned in the previous paragraphs, the nature of the data may be not only strategic and commercial but also sensitive in relation to external threats such as terrorism. Furthermore, the fact that the access points will probably be geographically dispersed will require thorough research into aspects of security and confidentiality.

3.3.2. System Architecture

The multiplicity of the profiles of the participants (for example airlines, airports and ATCCs) results in some information being of a "public" nature (i.e. accessible by everyone, like the operational agreement), some being shared (i.e. accessible by a restricted number of participants, like the contract of objective) and some being "private" (i.e. limited to one participant, such as a flight crew).

This multiplicity also means heterogeneity of the information management systems, even within a specific class of participants (for example, the operations management system put in place by Air France is different from that of British Airways).

Several axis could be explored, of which:

• a single standardised system which nevertheless has environments adapted to each group of participants;

• systems which are standardised on the basis of each group of participants (for example an airport system, an airline system, etc.);

• systems which are standardised for each process (for example for contract of objective, negotiation phase...);

• incorporation of requirements (particularly in terms of interoperability) and new functionalities in current or future systems put in place independently by each participant.

Within each of these research axes, several more options can of course be looked into, such as:

• a centralised or shared system; • availability and safety in relation to equipment redundancy (i.e. on the same site) or

duplication of geographical sites.



As in the case of network architecture, confidentiality, security and robustness (for example failure tolerance) will be essential.

All these choices are to be considered not only from a technical but also from a financial and political perspective.

3.3.3. Interoperability

Interoperability can be treated at a number of levels, both external and internal, the internal levels being partly linked to the approach taken within the framework of the system architecture.

External interoperability represents the incorporation of interaction with systems outside the "European area" (such as the USA).

Internal interoperability is more closely linked to the heterogeneity of European systems. Obviously, a single standardised system such as that mentioned in the previous section is by definition interoperable with itself.

In addition to these aspects, ground-air interoperability must also be ensured. A more precise term than operability would be operational continuity. The heterogeneity of the airspace and, in fact, the heterogeneity of control methods resulting from the autonomy of each ANSP, must not lead to an increase in the amount of equipment on board the aircraft or an increase in the number of "operations" to be performed by the flight crew. Before the infrastructure is put in place, therefore, an impact study should be performed on these various points.

Research skills

Systems engineering Network IT Security



4. THE TARGET WINDOWS

An aircraft's mission in the air consists in travelling from a departure aerodrome to an arrival aerodrome (a city pair). As things stand at present, the work of air navigation services (ANS) relates to the means used by aircraft to perform this mission:

• The airspace defines in horizontal and vertical terms the infrastructure on the basis of which the flight will be performed. It restricts how the aircraft will behave in both horizontal and vertical terms at all times.

• Air Traffic Flow management (ATFM) issues time restrictions relating to flight path points of departure.

• Control (ATC) issues instructions relating to heading, speed or altitude.

The management by objectives, (presented by Paradigm Shift) defines, for each flight, the reciprocal responsibilities of each of its actors by means of interim objectives. These objectives are expressed by means of target windows. These windows are defined explicitly by a four-dimensional position and size and, implicitly or not, by a respect rate representing the average proportion of flights respecting the contract. These windows fulfil a number of functions:

• They regulate the progress of flights in four dimensions. Thus they complement the Airspace Design and relegate the use of air routes to a local level, if needed. They allow regulations to be expressed in a full and effective manner, superseding current ATFM procedures based solely on the allocation of take-off slots.

• They create a strong link between planning and execution. The nature of this link maintains the initiative of operators with regards to the means used, and guarantees a certain degree of robustness in the face of disruption to the whole system.

• The nature of these windows opens the way for collaborative planning, making it possible to take into account expectations of all actors. By giving these actors guarantees, the target windows create value.

Putting such target windows in place involves jointly designing both an information system allowing operators to interact with these objects and corresponding working methods (see 3.2.3 and 3.2.1). This design effort could relate not only to static objectives (separation of routes in such a way as to minimise intersections) decided during the preceding design phase but also to dynamic objectives allocated by control operators alongside or instead of an order relating to an aircraft's means of action. These objectives allow the management of aeronautical problems to be both proactive (it affects the future rather than the present) and shared between control and flight crew (control defines the objectives and leaves some of the means at the pilot's discretion).



4.1. OPERATIONAL DECISIONS AND TARGET WINDOWS

The question here is to define the decision-making process of operators vis-à-vis a target window. It emphasises the flow of information supporting these decisions and the sharing of initiative between the operators. The protocol defining this flow and this capacity for initiative has consequences for the progress of operations:

• Aviation safety: Collisions must be prevented, the aeronautical limitations of equipment taken into account and disruptive phenomena controlled.

• Flight path quality: Subordination to objectives has a negative impact on the flight path actually followed by aircraft, associated with the possible inappropriateness of a command. On the one hand, aircraft must compensate for disruption which could divert them from the exit window. On the other, the operators' capacity for initiative is reduced, which prevents them from making best use of opportunities which present themselves.

• Workload resulting from information monitoring and decision-making mechanisms associated with servo-control.

• Punctuality: The system makes provision for a safety valve allowing operators to terminate the contract in order to disregard manifestly unsuitable instructions.

If these criteria are not taken into account, we could imagine, a lower safety level (more incident) due to an increase of ATC’s workload.

The information relevant to the target window is diverse in nature and origin. It relates to the traffic status (in a given navigation unit and its neighbouring units), aeronautical conditions, aircraft performance (flight domain and consumption) and disruptive phenomena. This information cannot be completely shared between ground and air.

While the target windows define common objectives, they also leave operational initiative a role to play. Sharing this initiative between control operators and flight crew influences the progress of the flight. While one individual attempts to safeguard against the consequences of a possible control action, aiming at a point inside the window, another attempts to aim at a point optimising the flight's financial profile, possibly at the side of this same window, and a third acts on the basis of problems expected much later on. This sharing of initiative and responsibility must also be carefully assessed with regards to the decision to terminate the contract.

The models introduced by this study do not attempt to take decisions for operators, even less to describe their decision-making process. Their aim is to define what information is needed and who is in a position to take appropriate decisions at a given moment. The aim of the modelling will be to introduce a line separating operators from the target window. This is because this horizon conditions the importance of disruption, the capacity of operators to remedy to a potentially dysfunction and the value provided by the operators' initiative (in terms of performance and safety).

This work will, of course, have to be brought into line with the research area described in 3.2.3.

Research skills

Operations: ATC and piloting Avionics: FMSs and engine power The mathematics of decision-making: − optimisation, automation − risk management, game theory



4.2. DISRUPTIVE FACTORS

It would be inconceivable to regulate the progress of flights and create a solid link between traffic planning and execution through the use of such target windows if the various possible forms of disruption are not taken into consideration. A thorough study of the various disruptive factors which have an impact on ATM needs to be conducted beforehand.

Uncertainty is the disparity observed between the planning done by air navigation actors and traffic as it really develops. Regardless of all efforts to reduce it or eliminate it, this disparity will always be an integral part of the aeronautical system.

It is the consequence of many different disruptive factors. A model is required which will describe this disruption in as much detail as possible. This understanding will serve as a basis for analysis and adjustments to the objective-based planning model based on target windows. Disruptive factors characterise all phenomena interacting with the performance of the flight resulting in modifications of its planning. The disruption applying to all aircraft is known as “air traffic disruption”. Disruptive factors generate the uncertainty with which the air navigation system has to deal on a day-to-day basis.

Problems relating to the propagation of disparities are dealt with by other components of the Paradigm Shift operational concept (modelling of target windows, renegotiation).

It is worth clarifying what these disruptive factors are, for the characteristics of each factor will give it a different status in terms of its impact on air traffic and, as a consequence, on ways of handling and managing it. The following needs to be developed:

• Occurrence of the phenomenon. • Its detection. • Its immediate consequences. These can affect the functioning of one or more aircraft and

lead to a decision with other consequences.

This study must serve as a support not only for decisions taken directly by operators but also for decisions taken when operators' tools and working methods will be designed and during the operational plan when the target windows will be developed. The flow of information associated with these phenomena must be specified in order to reduce their undesirable consequences at the lowest possible cost.

The Paradigm Shift Project has already performed a preliminary study of this question, which could serve as a starting point. This study led to the subdivision of disruptive phenomena into four categories:

• Ad hoc occurrences Ad hoc occurrences are discrete occurrences which happen daily in ATM. This category includes all factors whose start and end can be clearly seen and may relate to a specific flight or resource (portion of airspace, runway, etc.). The importance of such occurrences may vary considerably from one instance to another, depending on their extent, duration and how far in advance they are identified. They may relate to a technical malfunction, weather conditions (storm, strong winds, turbulence), medical emergency on board, etc. Of course, these events occur with a frequency which can be identified at the planning stage. For modelling purposes, each occurrence corresponds to a traffic state seen as a system of discrete states.



The most frequent ad hoc factors are as follows (not an exhaustive list):

- Logistical delays at airports. These may be attributed to the airline or to logistical structures at the airport. The aim of Airport CDM projects is to manage these disruptive factors more effectively by promoting exchanges between the various partners in order to obtain information as early as possible on whether or not disruption is going to occur and, if it is going to occur, what the nature of the disruption will be.

- Runway capacities. These depend on the airport's logistical structures, the weather conditions and the type of aircraft involved.

- Meteorological phenomena such as thunderstorms, turbulence or high winds occurring during flight.

- Occurrences on board aircraft.

• Permanent uncertainty

As their name suggests, these disruptions permanently affect the navigation system. They form the haze surrounding certain parameters, for two reasons:

- Measurement noise: regardless of the quality of the method and instruments used to ascertain the current status of the system (traffic and air mass), such measurement is subject to fundamental imprecision.

- Model noise: most of the parameters which make it possible to forecast the progress of traffic change over time. Their dynamics are therefore simulated by a model, which only reflects reality to a certain extent. Depending on the qualities of the model used, the latter may be unbiased (the value it forecasts corresponds to the variable expectation) but, as regards to most of the air mass parameters, dispersion around this value increases with the planning horizon (usually in linear fashion, in the case of additional noise). In the case of some situations (such as taxiing), no satisfactory forecasting model exists as yet. For modelling purposes, direct estimates result in a noise on the variable in question. For the dynamic models, it might be necessary to consider diffusion processes as differential stochastic equation solutions. All the system parameters are subject to uncertainty to some extent:

- The current aircraft position: This is one of the causes of the separation minima value. Current technologies using secondary radar have considerably reduced uncertainty in this respect.

- Aircraft performance, and in particular its flight domain (in order not to issue nonsensical orders), mass and consumption.

- Air mass properties: temperature, pressure and velocity fields. These parameters change in 4D according to a highly complex dynamic, and only very sparse and imprecise measurements of initial conditions are available. Nevertheless, these parameters influence the entire flight dynamic: envelope, velocity and consumption.

- Taxiing time.



• ATC-flight crew communications

The flight crew and controllers have different responsibilities associated with their capacity for initiative. They exchange information regarding the status of the system, express their intentions, formulate or apply instructions, etc. Unfortunately, these communications are imperfect (limited, slow and error-ridden) and, since every component has a different understanding of the situation, their initiatives sometimes lead to disagreements.

• The separation function

Control is based on the ability to change flight paths in order to prevent collisions. On a microscopic level, this is a never handing source of disruptions, regardless of the solution used to implement this function.

As a paradox, the more proactive a control tactic, the more it generates disruptions, since it applies to a greater number of aircraft and uses greater margins than do more reactive tactics because of the increase in permanent uncertainties with the spatio-temporal horizon. However, there are intrinsic limitations to this reactivity: the time taken to implement an order (time lag between controller and pilot), but also the reduced level of safety, because the advance warning needed to react to an unexpected event is no longer available, and the reduced performance of a control operator placed under stress (as against the fact that he or she has fewer situations to handle).

Research skills

This study is voluntarily limited to understanding and factually describing aeronautical phenomena from a quantitative perspective. It thus requires mathematical skills oriented towards stochastic models in addition to skills associated with the physics of the air mass and flight dynamics. Disruptions, of which the origin are anthropic, need to be examined from an operational perspective.



5. DECENTRALISED DESIGN

5.1. AIRSPACE DESIGN AND TARGET WINDOWS

Paradigm Shift brings many modifications to the role of ANSPs. Strategic sharing of traffic gives ANSPs a high degree of autonomy with regard to the design and operational implementation of the navigation system. This autonomy is regulated by the target windows.

The design phase allows each ANSP to prepare the resources corresponding to the task it must perform. There are many such resources: composition of the control team, sharing of responsibilities among operators, and airspace.

Paradigm Shift defines airspace as a set of constraints in four dimensions, relating to aircraft flight paths imposed prior to operations. The purpose of these constraints is to reduce the work of operators and establish a filter participating in air navigation safety, even if it decreases flight path efficiency.

Airspace constraints currently relate to the means deployed by aircraft during their flight: at a given moment, unless otherwise instructed by control, aircraft must fly along airways drawn in the horizontal and vertical plan. Similarly, controllers also express their instructions in terms of means: heading, speed and altitude. Target windows introduce the notion of constraints relating to objectives. This contribution has numerous consequences for the operators responsible for managing the future of traffic upstream of such a window (see 2.1). These operational changes must, of course, be taken into consideration from the design of the navigation system onwards.

5.1.1. Traffic Regulation

Target windows may also, moreover, serve to regulate traffic in such a way as to protect a sensitive area downstream of a window. An ANSP might, for example, use a target window to bring aircraft to precise points on the border of its airspace, with a view to separating their routes, specifying the flight level of aircraft entering the airspace or sequencing convergent flows over time. The limits of the scope of such "extended ATFM" must, however, be defined: although there is a great temptation to plan traffic in such a way as to ensure aircraft separation, the inappropriateness of overly strict subordination of flight paths to objectives must be taken into account (see 4.1). Account must also be taken of the possibility of failure of the guarantee offered by the target windows. Ideally, the target windows should serve to constrain flight paths just enough to prevent the formation of traffic bottlenecks. This approach goes hand-in-hand with an innovative approach to capacity and capacity management. It must be capable of supporting the heterogeneity of operational modes made possible by the decentralised management of the design. This is because, as one might imagine, a given operational mode and its network of constraints, which achieves the best possible compromise at local level between the supply of capacity, the demand for air links and the efficiency of flight paths, expresses specific needs in terms of protection against excessive traffic loads.

5.1.2. Internal Cooperation

The model of cooperation supported by target windows is adapted to interfaces other than the boundaries between districts. A target window expresses a demand for punctuality vis-à-vis the system upstream and a guarantee of punctuality vis-à-vis the system downstream.



This system is used at interfaces between smaller-scale areas of responsibility such as control sectors or traffic volumes. In terms of responsibilities, these local contracts relate only to the various entities concerned and possibly to the aircraft in question, and are not at the strategic level of the operational plan. The way in which the size of the windows decreases with that of the areas required to cooperate must balance the benefits and drawbacks associated with the level of detail of the prediction: optimisation of access to resources must be balanced against losses in terms of reliability and operational initiative.

These possibilities in terms of local-level traffic regulation in space and time make a considerable difference to the issue of sectorisation. They make it possible to consider autonomous local planning which would act jointly on the airspace, traffic and means of control (see Introduction chapter, Figure 1).

5.1.3. Flight Paths

Target windows describe the progress of the flight at strategic level. They constitute the aspect of airspace constraints which is discernible and visible to all. By introducing turning points, these restrictions might impact flight path efficiency: their horizontal position may divert aircraft from the great circle route, their altitude may lead them away from the optimal vertical profile, and their spacing in time may force them to travel at a velocity corresponding to suboptimal engine speed. As described in the study outlined in 4.1, the size of the windows also incurs an additional cost relating to flight paths, as a result of the obligation to compensate for disruptive phenomena affecting the flight and limiting initiatives by the flight crew with a view to adapting to situations which are partly unexpected. These effects cannot be assessed independently of operators' working methods, since they describe the sharing of their responsibilities, the flow of information and their capacity for initiative.

These costs associated with sub optimality are incurred by navigation services but met by aircraft and the environment. They generalise the notion of costs incurred by ATFM delays. Apart from its direct impact on these flight path-related costs, planning on the basis of objectives reduces the financial and operational risks (not to mention those relating to aviation safety) by providing guarantees with regard to the arrival time at the airport of destination . These various parameters affect the expectations of the various actors vis-à-vis the operational plan and their attitude while it is being negotiated.

Research skills

ATFM Airspace design: FMSs and engine power The mathematics of decision-making: − optimisation − financial models − operational research

5.2. STRATEGIC TRAFFIC

Paradigm SHIFT offers to have a decentralize approach of the Navigation Services, allowing autonomous organization of working methods, airspace constraints and ATC tools by ANSPs.

The aim here is to strategically analyze the traffic demand, introducing the air navigation services segmentation. This feature will permit to describe traffic demand without referring to predefined infrastructure.



The allocation of objectives goes hand-in-hand with the segmentation of responsibility for air navigation services.

Traffic demand, expressed in terms of city pairs, is understood as an objective at the level of air navigation as a whole. This objective is then declined on the basis of the chain of responsibility associated with the flight. Each flight is thus divided into segments with accompanying objectives, and each ANSP must ensure navigation for a set of sections.

5.2.1. Relevance

The relevance of this procedure is directly linked to that of the underlying sharing of responsibility. Of course, it is only really possible to assess the advisability of sharing of responsibilities in the light of how these responsibilities are performed. This is the subject of 5.1. The approach presented here, however, has the advantage of being completely free of existing infrastructural constraints. Coherent systems must therefore be constructed which implement the concept of functional blocks of airspace (FBAs), on the basis solely of traffic demand. A certain number of criteria proposed within the framework of the Paradigm Shift concept define the effectiveness of such a division:

• Stability of segmentation during the operational plan. The option of choosing an alternative "route" (in the sense of a chain of responsibility) at strategic level during the negotiation phase rethinks the principle of non-regression during the design phase. Within the framework of geographical sharing among ANSPs, this amounts to being able to determine the "shortest route" unilaterally.

• Resistance to disruptions. The progress of operations should have as little consequences as possible on the chain of responsibility, in order to avoid situations where an ANSP has to take in account an unexpected aircraft.

• ATC efficiency. "En-route" traffic is a group of aircraft acting in accordance with different priorities. Climbing aircraft must leave airport dealing with a restricted flight domain. Descending aircraft must concentrate inbound the same airfield, in trails. Managing these aircraft requires an overview of an area extending outwards from the vicinity of an airport in a radius of about one hundred nautical miles. Cruising traffic management, however, does not require any such geographical anchoring and would, on the contrary, benefit from a longer-term view favouring performance in terms of punctuality and flight-path quality. To be more efficient, the control should be segregated in different sub-systems more linked to the nature of the traffic.

5.2.2. A Possible Application: Dual Airspace

The concept of dual airspace turns this traffic segmentation to good effect by offering, within the framework of dense traffic, a network of responsibility centred on major airports, leading to the formation of bubble-shaped FBAs, known as districts, and a certain number of FBAs shaped like long ribbons, known as highways. These highways would provide a response to the formation of major continental flows. Such flows could be identified by associations of districts, frequently encountered in traffic segmentation, thus forming an unbroken chain of responsibility. Once the major flows are located, establishing a highway creates problem of intermodality. This is because each flight in the flow has a choice between following the highway and crossing each district in turn. The precise positioning of the highway, moreover, is a compromise between the various flight paths expected by the users and its quality improves if it meets their requirements precisely without taking account of the rest of the traffic.



The decision for each flight is, of course, made on the basis of financial calculation. The costs and benefits associated with each alternative must be quantified. Here, the costs associated with the 4D flight path proposed by each system during the design phase must be taken into account, as must as operational costs linked to navigation procedures (whether or not a route network is used, subordination to objectives spaced at greater or lesser intervals, etc.) and information benefits resulting from the punctuality guarantees provided by each mode. Detailed modelling will attempt to identify either saturation effects, which explain why each mode may become a victim of its own success (the case of bottlenecks) or, on the contrary, club effects strengthening the predominance of a particular mode (the case of mobile telephony).

The positioning of the highway is an operational research problem involving both combinatorial optimisation (choice of mode) and continuous optimisation (routeing).

5.2.3. Temporal Granularity

FBAs define how responsibility is shared in space. Each ANSP must also deal with local traffic composed of flight segments delimited by target windows with neighbouring ANSPs. In order to help ANSPs in their design phase, with a view to producing an operational agreement, it is nevertheless necessary to locate these segments in time. At this stage, however, the description of the traffic is not based on an infrastructure which makes it possible to anticipate flight paths. This description will be refined alongside the design. A description of the temporal plane accompanying this refinement process must be designed, in order to provide enough information at any given moment to allow a decision to be made without making assumptions which could be questioned later. In particular, a flight's initial time profile could be based on a statistical model.

Research skills

ATFM Airspace design The mathematics of decision-making: − optimisation − financial models − operational research



6. DUAL AIRSPACE

Traffic growth directly causes both an increase in the number of aircraft handled by controllers and an increase in the complexity of the perceived image of this traffic.

Today, the solution adopted to cope with these two problems has been to divide airspace on a geographical basis into smaller and smaller areas in order to limit the number of aircraft and thereby the complexity of the situation to be managed by controllers.

The approach chosen within the framework of SHIFT is very different. It aims at limiting the number of aircraft through segregation based on characteristics or properties directly associated with the traffic itself. Once this separation has been performed, each subset of the global traffic will be assigned to a completely independent and autonomous "control system" which is hidden to the others.

Within the framework of SHIFT, the aircraft's evolutivity is taken into account. An aircraft's flight can be described in terms of a "steady" phase (cruise flight) preceded and followed by two "evolutive” phases (climb and descent). On this basis, the following notions have been defined:

• the highway system, which manages a flow of aircraft in the steady phase; • the district system, which manages climbing and descending airport traffic and flights

which cannot join a highway.

This description leaves the door open for discussion on the concept of segregated airspace and traffic. Other criteria could be researched and could lead to different distribution concepts which could in turn be studied. This section covers only the aspects proposed within the framework of the Paradigm SHIFT Project.

While the systems described are managed independently and autonomously, this does not necessarily imply that they do not interact. This required further studying and principles must be defined which allow effective and safe coexistence.

6.1. THE HIGHWAY

A highway is characterised by an infrastructure on a continental scale which makes it possible to handle a major flow of aircraft in the steady phase (i.e. cruising aircraft).

This constitutes a large and open research field, with a real need for multidisciplinary approach.

6.1.1. Infrastructure

The approach chosen within the framework of SHIFT proposes to take into account all the components of the three pillars of air navigation: the airspace, the traffic and the ATC working methods and tools associated (Figure 1).

6.1.1.1. Structure

The purpose of highways is to handle major flows of cruising aircraft over long distances. A structure or number of structures must therefore be defined which can manage a heavy throughput of aircraft with various performance. It will also have to allow management of traffic off the highways.

How, in this context, can one consider the three-dimensional structure of a highway?



From what flight level will it start?

Will its "vertical" structure be:

• that of a series of layers of one or more flight levels over the whole of its length? • such that all flight levels will be accessible except in certain places where crossing

windows will be provided for district traffic? • neither of the above?

Will its "horizontal" structure be:

• such that traffic is differentiated on the basis of the direction in which it is travelling (for example north and south)?

• based on contiguous axis or on axis separated by a "no-go zone", if the above system of differentiation does come into force?

• such that each axis will consist of a number of routes, for example a route and a number of offsets?

• such that an axis will represent a volume in which aircraft are free to operate as they choose?

• none of the above?

These questions will all relate to more than operational contingencies (for example definition of capacity and working methods). The environmental aspects will also have to be taken into account.

Potentially, the highway represents a traffic "concentrator". It would thus be useful to study the impact in terms of pollution (emissions, noise, etc.) associated with the presence of the highway and the various highway structures listed.

6.1.1.2. Access mechanisms

The highway is not an end in itself and does not make it possible to serve airport platforms directly.

Mechanisms allowing aircraft to enter and leave the highway must be provided.

The distribution of entry/exit points must be defined, as well as access methods and associated protocols. The alternatives are:

• continuous access, i.e. it will be possible to enter and leave the highway at any point; • discrete access, i.e. "gates" will be provided at regular or irregular intervals along the

highway; • two-way access, i.e. it will be possible to enter and leave at the same point; • one-way access, i.e. each point will be dedicated either to entering traffic or to exiting

traffic; • access by means of an "airlock-type" mechanism.

6.1.1.3. Management body

The continental nature of the highway raises numerous points in relation to organisation and responsibility.

Will highway management be entrusted to a single body or to more than one? If the latter, will these divisions be along national lines or not?

If a "highway network" appears, will each highway be managed individually?



Will this management be done through the States, entrusted to private bodies or perhaps thrown open to competition?

What law will apply to this airspace? Will states delegate sovereignty over their airspace?

Who will manage route charges and monies payable by traffic using the highway?

Will incentives have to be defined for airlines which are to use the highway?

From an operational and legal perspective, who will be responsible for defining the routes and structure of the highway?

If the traffic on the highway is the responsibility of controllers, which rules will apply?

Will qualifications need to be harmonised throughout Europe and a "highway qualification" defined?

What will the consequences of all this be for the administrative responsibilities and civil and criminal liability of these controllers?

6.1.2. Adaptability

Air traffic is influenced by various uncertainties or variations, some of them cyclical (for example summer/winter traffic) and others occasional (for example meteorological disruptions).

What are the prerequisites if the highway structure is to enable highway evolutivity and "robustness" when facing with these disruptions, and what impact would this have on the highway structure?

Similarly, since the highway coexists alongside another system, will this adaptability impose constraints on that system?

6.1.3. Traffic Management

With regards to the management of traffic travelling along the highways, the field of research is very broad. Areas of interest include whether automation will be complete or partial and ground/air delegation (for example miles-in-trail).

A great number of studies can be undertaken in this field and suggesting an initial approach or orientation for them may constitute an hindrance to creativity.

6.1.4. Control Support Tools

Since working methods and highway management could be very different from those used today, it is reasonable to assume that requirements at the level of the control position will also be very different, and it would appear difficult at this stage to suggest a given path since given that the field of research is so open. Once the studies on human factors aspects and working methods are under way, it will be useful to launch an exploratory study in order to define an initial prototyping for these tools. The process of definition and deployment can then continue in close cooperation with operational staff, human factors experts and industry.



Several axis can be looked into with regards to these tools:

• A presentation of the information which helps perception and comprehension of the situation (for example, displaying information relating to aircraft punctuality at the highway entrance).

• Aid systems which would allow controllers to analyse and choose between a number of alternatives in order to preserve aircraft separation while ensuring that punctuality objectives will be met.

• Tools allowing the controller to manage and improve his own cognitive mechanisms, and more precisely his operational memory (principles developed within the framework of the ERATO study, for example). This type of tool (for example a task diary) could be very useful in reducing the controller's cognitive workload.

• Warning systems allowing the controller to concentrate on the objectives of safety and performance (for example a mechanism for monitoring instructions given to aircraft).

6.1.5. Human Factors Aspects

Highways are designed to have a high capacity. This capacity increase is made possible only because aircraft have less space in which to operate, which means that tactical control operators have less room to act. To increase the amount of traffic in airspace such as highways is to create a continuous flow of aircraft. In this airspace, notions of aircraft management and control will be different from today's. Predicting aircraft flight paths will be a wider concern. The airspace will take partial responsibility for safety. This is because there can be no crossing conflicts if aircraft remain on their routes. Only “closure” conflicts will persist and will need to be managed. All these impacts mean that the working methods of tactical control operators must be considered from a different angle. This is a huge field of research. It raises four questions.

• The first question is that of the usefulness of aircraft-based control as it exists today. In aircraft-based control, the aircraft is the subject of control. This means that the control operator must know everything about the aircraft, i.e. its current and future parameters in four dimensions. The result for the operator is a large amount of information to process which rapidly exceeds human capacities once traffic becomes dense. With flow-based organisation, the number of parameters is reduced because the room for manoeuvre is curtailed. The results of the Supersector Study, however, have shown that even here the limits of human memorisation, comprehension and decision-making are quickly reached once traffic loads become heavy.

Therefore, to respond to the challenge of capacity, a different level of granularity must be taken in consideration in control, i.e. the subject of control must be changed. Highways are a step in the right direction. Can a flow-based system, such as that used in other transport systems like railways, not be suitable for the highways? The subject of control is thus no longer the aircraft but a cluster of aircraft or a flow. This supposes transferring certain functions to aircraft, as proposed within the framework of the ASAS projects, which might find this a relevant field of application. Flow-based work at tactical level calls for a rethinking of the granularity of the information to be used, and of working methods and support tools for control operators. These are all innovative questions which deserve to be dealt with as thoroughly as possible.



Once incorporated into the SHIFT Project, they take on an operational value which does not prevent the thinking done from being transferable to other airspace concepts.

• The second question is that of the industrialisation of air traffic control. By limiting the scope of the controllers' activity and the aircrafts' room for manoeuvre, we circumscribe the field of air navigation movements. A system is thereby established which is more transparent in terms of its productivity. In other words, there is greater visibility for anticipating ATC actions and thus predicting ATC performance. It is thus possible to define performance objectives with greater precision and achieve them at the same time as regulating entry to the highway, i.e. the traffic. The full implications of this approach will emerge only if it is accompanied by an approach to modelling which aims at greater efficiency.

• The third question is that of the sharing of tasks among highway operators, and therefore of the number of operators. Within the framework of the SHIFT approach, the highway is considered as a control unit. This control unit, however, bears little resemblance to those of today. Without wishing to predict its final form and organisation, the highway as a concept is characterised by its length and vertical distribution in space. Whatever the working procedures defined in relation to the material presented above, a study must be undertaken on the number of operators responsible for the highway.

• The fourth and last question is that of automation of control of the highways. If the concept of the industrialisation of ATC is taken to its extreme, the basis for automation of ATC functions is put in place. This question is relevant in terms of human factors, because it raises the issue of the place of the human being in the framework of an automated system. Clearly, automating ATC functions is of no use unless: • it enables a major leap forward to be made in terms of capacity; • it leaves no human operator in the decision-making and comprehension loop (which

implies full autonomy); • it is responsible for its own results; • it is accepted by the human operator.

The place of the human being in relation to the automated system must therefore be changed. His or her role must develop from that of first-line operator towards that of supervisor of the automated system. The term "supervisor" here refers to an individual who creates the conditions under which the automated system can function optimally in accordance with priority criteria which may change on the basis of the situations to be managed. The supervisor is not a judge of either the quality or, consequently, the results of the functioning of the automated system. He or she does not have the capacities to do so. The whole approach in relation to automation will aim to define:

• the principles leading the acceptability of the automated system in human factors terms, within the framework of the transition between the present situation and full automation of the functions;

• the nature of the supervisor's functions; • the modes of interaction between the supervisor and the automated system in

difficult situations.



Research skills Human factors Operations Airspace design International law and legal aspects Design ergonomics Automation

6.2. COEXISTENCE

6.2.1. Criteria

The notion of "dual airspace" is based on traffic segregation on relevant parameters, in order to reduce the complexity of this traffic for the operator. This has led to the emergence of the highway concept, with traffic segregation based on evolutionary (climb and descent) and stable (cruising) flight phases. This is only one alternative within this approach, however. Other parameters could be brought into play.

Studies allowing other possible solutions based on other parameters/criteria could be useful and might lead to separation into three or more systems.

6.2.2. Organisational Prerequisites

Traffic cannot, however, be segregated into an infinite number of control systems. In addition to the relevant criteria which might lead to such separation, the operational aspects of the problem must nevertheless not be forgotten. A form of segregation involving "continuous" transfers from one system to another would have no future.

Studies must therefore be done on the nature of the "requirements" associated with a valid form of organising this coexistence. This is because the results of such studies could also lead to the definition of a conceptual framework which would guide or make it possible to narrow down field research relating to the segregation criteria referred to in the previous section.

6.2.3. Coordination and Interaction

Coexistence necessarily involves interaction and coordination. As mentioned in the previous section within the more structural framework of coexistence, it is conceivable that the methods of coordination and interaction between the various types of airspace could make the segregation irrelevant.

Therefore, it could be useful to define "generic" mechanisms or requirements with regard to coordination and interaction. These could play the role of filters between the various segregation systems.

Obviously, coordination must be based on tools allowing controllers to manage effectively these "boundaries" between various systems. Here too, individual needs will depend to a large extent on the actual structure of the systems considered. An approach to the various axes as defined in 6.1.4 could, however, allow the development of specific tools for each type of segregation.



It should also be noted that, in addition to those aspects of coexistence associated with the segregation of systems, the heterogeneity of airspace design (sectorised, free flight, etc.) introduced by the "local" autonomy of each ANSP (dealt with in 3.3.3) will require studies, making it possible to define tools assisting the controller's work (and ensuring operational continuity) in these "buffer zones".

6.2.4. Human Factors Aspects

The coexistence in tandem of two types of airspace, each with a different operating mode, is not an entirely new concept in air traffic control. The separation of airspace and control regimes, together with the juxtaposition of military and civil traffic, are examples of coexistence today.

The coexistence proposed within the framework of SHIFT goes further because it integrates two types of airspace and creates cross-over points between the two. This reveals two alternatives:

• what might be termed as "passive coexistence" between the two types of airspace; • as "active coexistence" or connection of the two types of airspace.

The term "passive coexistence" refers to the two systems coexisting side by side without any operational links. Passive coexistence raises two questions:

• the opacity or transparency of one system against the other; • the impact of the organisation of one system on the management and control of aircraft in

the other system. The principle behind passive coexistence is that the two systems should as far as possible be sealed off with the exception of the connection areas. However, this would have one limitation: emergencies. Then, the question is to know of knowing whether operational “obscurity” must also be accompanied by sealing off the two systems in terms of information. It is important to discuss this question because it will have a direct impact on the workload and situational awareness of the controllers responsible for each of these types of airspace. Moreover, sealing off must also be discussed in relation to responsibility. To give a controller information is also, under the current criminal-law system, to transfer liability to him or her. Clearly, the answers are not obvious and must be analysed globally. They may raise other issues such as how controllers are to be assigned to one type of airspace or the other.

The impact of the organisation and structure of one type of airspace on the other will be felt mainly at the level of districts. This is because no matter what operational mode is in force in a district (free routes, standard routes, etc.), it will be crossed by ribbons of “no-go” areas. This will restrict the district's remaining airspace and therefore be constraints for controllers. These constraints will limit the room for manoeuvre of aircraft and thus also the room to act of controllers. With regard to managing and controlling aircraft, the workload is liable to become heavier and the development of situational awareness more complex. It is therefore important to look into:

• the impact on tactical control operators of the limitation of their airspace; • the least damaging highway structure for district controllers, while bearing in mind the fact

that the highway must also meet capacity and efficiency objectives. The connections between the two types of airspace are a vital issue for dual airspace. The operational continuity of flights will be achieved through these connections. These connections raise the problem of the transition between two operating modes for managing and controlling aircraft. They represent an interface which creates a true "airlock" between two systems of constraints. The responses to the question of designing this "airlock" are both structural, at the level of the airspace, and operational, at the level of the working methods.



From an operational perspective, the "airlock" must be managed on the basis of the contract of objective. But should the management of the "airlock" be autonomous or incorporated into one of the adjacent systems (district or highway)? In other words, a response must also be found to the question of the number of tactical control operators who are to manage this transition. Clearly, the task associated with the connections is a new one and requires specific procedures. The design of these connections must be based on an operator-centred approach in order to take account of the workload. It must also take account of the specific characteristics of the highways and the potential heterogeneity of the districts.

In this context, compliance with the contract of objective will require aircraft to arrive at certain points in four dimensions. Specialised tools will be required to this end. Connecting the two types of airspace is a real challenge in human factors terms because a new task must be designed in a complex environment.

Research skills

Human factors Operations Airspace design International law Design ergonomics Automation Mathematical modelling



7. CONCLUSION

This research agenda marks the end of the Paradigm SHIFT concept definition phase. It operationalises the concepts described in the OCD in terms of research objectives. It has the advantage of presenting a research strategy with a view to pushing forward with the research.

The research agenda is intended as an initial outline and does not claim to be exhaustive. It is a canvas around which a body of research can be structured . This will contribute to more precise definitions of SHIFT concepts.

Among the research areas identified, there are clearly major inequalities in terms of knowledge acquired to date and resources to be mobilised in order to investigate them. The agenda's usefulness should make it possible to create synergies between subject areas, which will emphasise the operational purpose of the studies. The agenda thus also plays a role in bringing

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EUROCONTROL EXPERIMENTAL CENTRE · V1.1 15.6.05 Approved version . EUROCONTROL Paradigm Shift - Research Agenda ... Proof of Concept Assessment. 23rd Digital Avionics System Conference,