Tactical trajectory optimisation should consider the total expected cost of the flight (fuel and delay). The cost of fuel can be estimated from the expected fuel usage. The cost of delay can be approximated by simple non-linear functions but, we propose a methodology to explicitly consider its different components: passenger related (regulation 261, duty of care, missed connections and soft costs), crew and maintenance, and reactionary costs (delay and curfew). This explicit modelling captures the non-continuous aspects of the cost function, which can significantly impact the optimisation profile, e.g. ensure that missed connections are reduced.
The cost of delay, dependent on the arrival time at the gate, can be subject to uncertainties which are inherent (e.g. if a passenger will or not miss a connection) and external (e.g. taxi-in or holding times). Therefore, the optimisation framework should estimate the arrival time to the gate (not the runway) while considering these associated uncertainties.
The described architecture models the processes affecting the cost (e.g. considering probabilities of missed connections or explicit propagation of delay) and operational aspects at arrival which impact the realisation of the planned optimised trajectory (holding time, sequencing and merging distance (tromboning), and taxi-in time). The consideration of the operational uncertainties enables the estimation of the probability of achieving the flight on-time performance.
All these operational uncertainties are integrated into the cost function producing a total expected cost as a function of arrival to FL100 during the descent at the arrival airport.
The trajectory is then optimised in its vertical and speed profile finding the cost index which is expected to minimise the total costs with a simulated annealing framework.
The first results presented describe how the cost functions are generated, uncertainties considered and trajectories optimised for a flight in the LEDM-EDDF route.