The Vortex Position Estimator used for the Airbus fello'fly Transatlantic Crossing

In November 2021 the Airbus fello’fly project completed two transatlantic formation flights demonstrating a reduction of fuel consumption of 5% trip fuel for the follower. The follower achieved this by maintaining an optimum lateral position relative to the wake vortices generated by the leader. The flights were achieved automatically via the existing auto flight system, modified such that commands to the autopilot outer loops could be provided by additional real-time computers.