Validation projects

Calculated Take-Off Time (CTOT) and Target Time of Arrival (TTA)

Release: 2015

Reference: -

Location: Brussels


CTOT is a tactical slot allocation time calculated to determine the time at which a flight is required to become airborne. Target Time of Arrival (TTA) is a progressively refined planning time that is used to coordinate between arrival and departure management, and to support DCB. This solution provides a complete set of DCB measures (including Dynamic Airspace Configurations) combined with 4D constraints that are needed to optimally adapt airspace capacity to the demand and minimize demand adjustments. Integrated airspace and 4D constraint solutions are obtained through an iterative optimisation and Collaborative Decision Making (CDM) processes involving local, sub-regional and regional levels.

Description of the exercises

Live trials in Palma, Barcelona and Brussels will build on the CTOT/TTA concept, adding Target Time Over (TTO) for en-route constraints, and validating its feasibility with input from all actors involved (Flight crew, Airline Operational Center AOC, Network Manager). The trials cover the communication of both planned measures (e.g. TTO/TTA) and derived measures (e.g. CTOT) to relevant actors as targets, aiming to ensure that the flight is performed in line with the plan. The trials will also validate the feasibility and benefits of the AOP-NOP integration using SWIM. This integration involves the timely exchange of relevant airport and network information, resulting in a common situational awareness and improving both network and airport planning activities, as well as improving operational performance. In particular the exchange of arrival and departure planning information, airport capacities and event planning will be validated.

Expected benefits 

  • Improve information sharing
  • Enhanced predictability
  • Increased cost effectiveness