Expected results

Impacts on the "ATM Target Concept" of SESAR:

The 4D contract notion is a trajectory-based operation implementing the ATM Target Concept that is one of the main results of the SESAR. A trajectory representing the business/mission intentions of the Airspace Users and integrating ATM and airport constraints is elaborated and agreed for each flight, resulting in the trajectory that a user agrees to fly and the Air Navigation Service Provider (ANSP) and airport agree to facilitate.

The trajectory-based operations ensure that the Airspace User flies its trajectory close to its intent in the most efficient way to allow minimizing its environmental impact. The concept has been designed to minimize the changes to trajectories and to achieve the best outcome for all users. In that respect, user preferred routing will apply without the need to adhere to a fixed route structure in low/medium density area. The Airspace User owns the Business Trajectory (BT) and has primary responsibility over its operation.

Where ATM constraints (including those arising from infrastructural and environmental restrictions/regulations) need to be applied, finding an alternative BT that achieves the best business/mission outcome within these constraints is left to the individual user and agreed through CDM process. The owners' prerogatives do not affect ATC or Pilot tactical decision processes. The business/mission trajectories will be described as well as executed with the required precision in all 4 dimensions."

In the SESAR D3 document "The ATM target concept" the notion of 4D trajectory is introduced but there are a lot of ambiguity around this term. So 4DCo-GC could clarify most of the questions around the term "4D business trajectory" - define the required precisions, estimate constraints, describe requirements to future planning systems and data links and etc.

The aim of this work is to draw a path for implementation of trajectory based operations and mark-out the main practical problems and required research programs. E.g. the questions of environmental impact mentioned above are considered in T 230 of 4DCo- GC. The questions of elaboration of business trajectory are covered by tasks WP100, 200. The process of finding alternative BT through CDM is covered by tasks 150, 210.