City-pair trajectory optimization in the presence of winds using the GATAC framework

This paper presents work that complements on-going activities on trajectory optimization currently taking place within the Systems for Green Operations (SGO) Integrated Technology Demonstrator (ITD) of the Clean Sky Joint Technology Initiative (JTI). Within the SGO ITD, the Greener Aircraft Trajectories under ATM Constraints (GATAC) framework is being developed and used for multi-criterion trajectory and mission optimization. This paper addresses trajectory optimization work that has been carried out using GATAC taking into account the effect of winds. It presents a brief overview of the GATAC framework followed by an address of the requirements and methodologies used in the design of a wind model that makes use of wind data available on the National Oceanic and Atmospheric Administration (NOAA) website. Using this data, the wind at any position over a defined area is obtained by making use of tri-linear interpolation. This discussion is followed by the validation of the implemented wind model. A mission between London Heathrow Airport (EGLL) and Malta International Airport (LMML) was adopted as the case study to be optimized, with data recorded from a real flight being used as the baseline trajectory and aircraft performance, as well as a means to confirm the matching (validation) of the models with the baseline aircraft, an Airbus A320. The results of the optimization using GATAC to perform a bi-objective optimization using fuel burn and flight time as the two criteria are also discussed.