Current Separation Minima (SM, i.e. minimum distances aircraft need to fly apart from each other at all times to ensure safety) were defined in the late 1940's for en-route and in the 1970's for airport operations, based on expert judgement and technology available at the time. Despite the gigantic leap in technology since, but a few SM have been modified on the grounds of modern technological capabilities (e.g. RVSM). Conversely, the main current ATM system challenge is to manage the air traffic demand increase expected over the coming years. According to forecasts, year 2000 demand is expected to treble by 2020.
The RESET aim is to identify what reductions in SM could be realised to meet the following challenging goal: 'Where feasible, reduce SM so that they contribute towards enabling a safe factor of 3 traffic growth over Europe'. At least three potential separation standard modifications will be selected for detailed safety, efficiency and economic assessments. One of these will consist in constructing a regulatory basis case study on Time-Based Separations for approach operations, an emerging procedure aiming at maintaining airport arrival capacity in strong head-wind conditions.
SM could become a constraining physical factor limiting capacity growth. Additionally, operational concept improvements will also be required to deliver extra capacity, brought about by new technologies, evolving controller & pilot roles and changing tasks and procedures. Using the C-ATM Phase 1 Concept as staring point, RESET will address both issues in combination by:
- Identifying per flight phase, feasible SM reductions contributing to safely reaching the x3 traffic increase;
- identifying what traffic growth and reduced SM mean for pilots and controllers roles, tasks and responsibilities;
- developing safety, efficiency & economy assessments for reduced SM and assessing their impact on technology needs;
- providing adequate evidence and justification to press for changes in SM.
The main objective is to identify what reductions in separation minima are safe and feasible to contribute towards enabling a 'factor of 2' (x2) growth over current European traffic.
The following nine specific objectives are steps towards achieving that aim:
- derive from the 'x2 traffic load over Europe', a set of separation minima targets for the various phases of a gate-to-gate operation;
- identify gaps in enabling the 'x2' by the operational concepts and technology in other projects;
- develop a qualitative (and quantitative where possible) model to capture the rationale of existing and future separation minima standards;
- develop high-level advanced operational concepts;
- identify how to accomplish the process of change;
- prioritise and select (at least) three separation minima potential reductions for detailed safety, efficiency and economic assessment;
- identify and apply methods to safely (fulfilling ICAO/ESSAR requirements) and cost effectively assess the prioritised separation minima reductions;
- feed back the outcome of the safety and economy assessments;
- disseminate the RESET developed process of change across the ATM community.
In order to accomplish the objectives we decompose the problem into a hierarchy of sub-problems each of which could be analysed without the need to solve the next sub-problem. Basically, the resulting sequence of sub-problems to be solved is as follows:
- the first objective is to derive from the 'factor two traffic load over Europe' goal setting how much reduction is required of the separation minima during the various phases of a gate-to-gate operation. The realisation of this sub-objective leads to the target separation minima to be further studied.
- The second objective is to identify gaps in enabling the factor three goal setting by the advanced operational concepts and technology developments in the ongoing European projects C-ATM Phase 1, SESAR, OPTIMAL, TBS (Time Based Separations), ASSTAR and EMMA projects. This allows RESET to focus on the gaps and to promote ongoing developments which already address the longer term well.
- The third objective is to develop a qualitative (quantitative where possible) model to capture the rationale of existing and future separation minima standards. Such a qualitative understanding of separation minima is essential in the development of future operational concepts which take advantage of reduced separation minima.
- The fourth objective is to develop a high level, advanced operational concept which complements the novel separation minima in order to safely accommodate the 'factor three traffic load over Europe' goal setting. The key issue is to identify the advanced roles, tasks and responsibilities of pilots and controllers together with the new procedures and technology.
- The fifth objective is to identify, in collaboration with the relevant safe separation organisations (i.e. ICAO, Eurocontrol, ANS providers, airlines and national regulators) how the process of change for the separation minima should be accomplished. This process of change will also include the identification of what separation minima reductions have to be addressed with the highest priority.
- The sixth objective is to prioritise and select (at least) three separation minima potential reductions for detailed safety, efficiency and economic assessment. One of these selected assessments will consist in the construction of a regulatory basis case study for Time-Based Separations in airport approach operations.
- The seventh objective is to identify and apply appropriate methods to assess whether the prioritised separation minima reduction
Some of the project achievements are as follows:
- The RESET project has completed the definition of the project goals, meaning a description of possible separation minima reductions that can help fulfill the capacity requirement. The next step was the prioritisation of the reductions and the selection of the three best cases for a deeper analysis.
- A list of current separation standards was built including those of different regulators, phases of flight and conditions. After an initial analysis of this catalogue, several conclusions were obtained: depending on the regulator, different values are used for the same standard under similar conditions, there is a lack of information regarding the rationale behind most of the standards, sometimes different categorizations used by different regulatory bodies exist that have a big impact on the application of the standards.
- The separation budget model was started, based on the current separation minima foundations. This model could be useful later on for assessing the impact of new technology on the reduction of separation minima.
- The gap between the on-going operational concepts and the RESET scenario has been identified.
- The process of change needed for modifying regulations has been analyzed.
- The safety methodology that will be used to study the selected cases has been defined.
- Hazard Analysis of the selected cases (TMA T1, TIPH and TBS) has been performed, resulting in Task Analysis and Crystallization Reports generation.
- Mitigation Workshops have been performed and results analysed.