Minimising emissions from flights through realistic wind fields with varying aircraft weights

The international aviation community has agreed to advance actions to reduce CO2 emissions. Adopting more fuel-efficient routes will achieve this goal quickly and economically. Full satellite coverage of transatlantic flight routes is now a reality, allowing us to consider moving from the Organised Track Structure to Trajectory-Based Operations. Here, fuel-optimal trajectories through wind fields from a global atmospheric re-analysis dataset are found using dynamic programming. The control variables of aircraft headings and airspeeds are varied to find free-time, fuel-minimal routes. Aircraft fuel consumption is modelled with a new model-specific fuel-burn function, which incorporates aircraft mass reductions as fuel is burned. From 1 December 2019 to 29 February 2020, fuel use from simulated routes is compared with fuel estimates based on recorded flight data. Results demonstrate that an average fuel reduction of 4.2% is possible without significant changes to flight duration. This equates to a reduction of 16.6 million kg of CO2 emissions. Therefore, free-time, fuel-minimal routes have the potential to offer substantial fuel and emissions savings.