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Airborne Separation Assistance System Thematic Network

European Union
Complete with results
Geo-spatial type
Project Acronym
STRIA Roadmaps
Connected and automated transport (CAT)
Network and traffic management systems (NTM)
Transport mode
Airborne icon
Transport policies
Societal/Economic issues
Transport sectors
Passenger transport,
Freight transport


Background & Policy context

ASAS-TN is a stand-alone project, arising out of the ASAS work within the programme of Co-Operative Actions of R&D In EUROCONTROL (CARE-ASAS). It is organised within the work programme for Competitive and Sustainable Growth of the European Community, Key action 4, New Perspectives in Aeronautics, Target Platform 4, 'More Autonomous Aircraft in the Future Air Traffic Management System'.

Airborne Separation Assistance Systems (ASAS) is a new technique which, via airborne and/or ground surveillance, presents a flight crew with a traffic picture.

The flight crew may then use the information in a defined way to achieve some operational benefit. This use is defined as an ASAS application and may range from enhanced see and avoid to an aircraft managing its own separation.


The main objective of the ASAS Thematic Network is to accelerate the implementation of ASAS applications in European Airspace taking global applicability in order to increase airspace capacity and safety. 

The main ASAS Thematic Network outputs consist in the sharing of the current knowledge on ASAS between all European stakeholders and in recommendations for future activities required to reach the operational use of ASAS applications.

It is expected that these results will be of use to guide future EC actions from 6th Framework RTD projects to shorter-term TEN-T pre-operational experimentations.

The expectation is also that the shared knowledge and the agreed upon recommendations will allow European industry to optimally plan and focus their new products development strategy.


The two-year project provides a series of workshops on key ASAS issues; a set of web-based discussion forums; work on ASAS research and development, standardisation and certification issues; and a document repository of ASAS related material.

Communication activities are performed by:

  • the creation of an Internet based set of moderated ASAS discussion forums;

  • a Web-based ASAS document repository;

  • three ASAS workshops;

  • a seminar and

  • the development of guidelines for the implementation of ASAS applications.

The main ASAS Thematic Network outputs consist in the sharing of the current knowledge on ASAS between all European stakeholders and in recommendations for future activities necessary to reach the operational use of ASAS applications.

The three ASAS-TN workshops are:

  • 'ASAS Expected Operational Improvements', 28-30 April 2003, Rome.

  • 'ASAS applications & Procedures', 6-8 October 2003, Stockholm.

  • 'Required airborne and ground functions for ASAS', 19-21 April 2004, Toulouse.

The Final Project Seminar will be held on 11-13 October 2004.


Parent Programmes
Institution Type
Public institution
Institution Name
European Commission, Directorate-General for Research (DG Research)
Type of funding
Public (EU)


After two years of activities, providing a network for the exchange of information, organising workshops, and developing recommendations for implementation (the projects has produced 3 themed workshops with associated final reports, an ASAS Implementation Strategy, a Final Seminar with associated report, and finally a web-site of ASAS related information.), the ASAS-TN consortium came to the following conclusions:

  • Significant progress in the global harmonisation definition and the validation of ASAS and ADS-B applications and particularly on the applications included in ‘Package I’ has been made. As for any new concept elements of the future ATM (Air Traffic Management), work is still needed.
  • Airspace users are convinced that ASAS and ADS-B applications will be an integral part of the future ATM system. The benefits of these applications are promising but it is necessary to confirm these claims through work on validation, safety, certification, benefits versus costs, etc... The commitment of the airspace users is essential and needs to materialise.
  • ASAS and ADS-B provide a set of applications which are designed to work as an integral part of the ATM system and activity to ensure this integration must be undertaken. ASAS applications do not necessarily compete with new concept elements such as ‘4D (4 Dimensions - i.e. Longitude, Latitude, Altitude and Time) concepts’. For example, work is currently being performed on the integration of arrival manager (AMAN) and the airborne spacing application called ‘sequencing and merging’.
  • The ASAS-TN has proved to be a valuable enabler to progress ASAS and ADS-B. As an open forum for discussion it has acted as a catalyst in the understanding and acceptance of these new ideas. Global stakeholder participation has been excellent. However, an increased participation of aircraft operators, particularly the airlines, and airport operators would be very beneficial.

ASAS-TN significantly contributed to international S&T (Scientific and Technological) Co-operation, with representatives from the USA (FAA, Mitre, NASA and Boeing) Australia and Japan. All major European Stakeholder groups contributed.

Technical Implications

The ASAS implementation decision process is spread across the ATM stakeholder community and across Europe. Because of the project’s wide contact across the ATM community of ASAS-interested stakeholders the outputs will influence operational and equipment standards, influence research programmes and ensure the global interoperability of all initiatives. This will produce economic, social and environmental improvements with the eventual and accelerated implementation of ASAS. The process continues with the follow-on ASAS-TN2 project.

Policy implications

Over the last years, ASAS and ADS-B applications have gained international recognition. Positive progress towards acceptance has been achieved. Even if it is recognised that there are still many issues to be addressed. The ASAS-TN consortium invites the global ATM community to accept the following commitments.

  • Commitment 1: ASAS and ADS-B applications shall be an integral part of the European ATM Master Plan. They have the potential to enhance the ATM system in the areas of safety, capacity, flexibility, efficiency and environment.
  • Commitment 2: It is now necessary to conduct operational trials in Europe involving revenue flight. This will include in-situ certification and operational approval of the applications.
  • Commitment 3: ASAS application must be studied as an integral part of the ATM system. Synergies with other new concept elements should be identified in order to maximise benefits.
  • Commitment 4: Stakeholders must participate in ASAS-TN2 activities to ensure a common understanding. In addition to workshops and seminars, these should include contributing to the ASAS-TN2 library and providing inputs to the Internet forums of discussion.


Lead Organisation
EU Contribution
Partner Organisations
EU Contribution


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