Aim of the project was to go deeper into the definition of the '4D contract concept' that had been developed in the FP6 IFATS (Innovative Future Air Transport System) project and was mentioned in major research programmes and projects such as SESAR (IP3), ASAS (Airborne Separation Assistance System) and NEXTGEN.
The 4DCo-GC project aimed at exploring the concept of '4D Contract guidance and control of the aircraft' as a step change in air transport operations by providing a more radical and environmentally efficient solution for management of the airspace. Scientific objectives of 4DCo-GC were:
- To model 4D contract concepts (on strategic, tactical and emergency levels);
- To develop the algorithms (strategic, tactical planning), process and functions (failure management, emergency separation) needed to use 4D contracts;
- To define and develop a global tool architecture to demonstrate and analyse the key operating advantages of the 4D contract concept, including man's role;
- To elaborate an assessment methodology and metrics to qualify and quantify 4D contract characteristics and performances for control and guidance of the aircraft;
- To perform a real-time assessment of 4D contract concepts of operations - organise dissemination and demonstration workshops in front of an external audience;
- To derive, from this qualification and quantification work, recommendations for future 4DT system development.
Project 4DCo-GC brought together the expertise of 13 European and associated partners coming from 7 countries. The project was built on the results of several past EU programmes and projects.
The main expected results from the 4DCo-GC project were technological components (software/hardware/architectures) and recommendations for future 4D trajectory guidance and control systems, addressing several priorities of ACARE. Regarding the short/middle-term expected evolutions of the European air transport system, 4DCo-GC was fully aligned with the orientation of SESAR, and particularly the so-called 'ATM Target Concept'.
4DCO-GC has effectively advanced the definition of multiple systems to enable more automated aircraft operation, from collision avoidance to health monitoring. If exploited, the results would increase savings and enhance sustainability thanks to more efficient travel. Last but not least, the 4D contract concept will validate Europe's leadership in air transport and propel the aviation industry to new heights.
The project resulted in the following findings:
Aircraft guidance and control
- It is possible for aircraft to follow 4D contract with a satisfactory efficiency;
- Ability to recover from technical problem - Aircraft can self-generate an alternative trajectory;
- Optimisation of trajectory within the 4D contracts - Theoretically feasible, with significant fuel savings (several %).
4D contracts - planning
- It is possible to generate 4D contracts at European level, for one entire day - Even for more than twice the current traffic; Simulation of traffic over the whole of Europe is difficult due to required computation resources;
- It is possible to optimise the arrival and departure sequences, to a certain extent - Integration of optimal arrival/departure sequences within the 'air picture' would require additional research.
4D contracts - execution
- The size of the bubbles has an impact on the number of necessary replanning - Increase of 'thickness' (z axis) enables a reduction in the number of replanning more effectively than the other axes;
- Replanning involves a maximum of 2 aircraft - Most of the time, only own ship contract modification is enough; Algorithm works with more, but this situation never occurs;
- 'One of the biggest problems for all scenarios was to find/create a conflict'! - Provided simplified wind assumptions;
- Contract potential non-compliance can be forecast - Maximum time horizon of 10 minutes;
- Degraded / emergency situations can be managed - Need to combine several failures to trigger the 4DLC.
An efficient and integrated mobility system:
- Secure Transport
- Acting on transport safety: saving thousands of lives