Inspired by biomimicry, Airbus (Stand 940; Pavilion P10) unveiled at the Dubai Airshow a project, Fello'fly, aimed at demonstrating the technical, operational, and commercial benefits of having two or more aircraft flying together to reduce fuel consumption, much as birds do.

“When birds fly in formation, they are using the updraft of the wake of the previous bird, therefore they have 'free' lift that reduces their own consumption” of energy, said Sandra Bour Schaeffer, head of Airbus Group Demonstrators. 

Calling the concept “wake-energy retrieval,” the demonstrator project aims to harvest the otherwise wasted kinetic energy generated by an aircraft wing, allowing a properly positioned aircraft in trail to reduce its energy consumption from 5 to 10 percent, without affecting passenger comfort. Tests conducted last year with two A380s confirmed the findings, Schaeffer said. 

Airbus has discovered that rather than the tight formations seen in the avian world, the ideal zone for aircraft wake-energy retrieval is about 3 km, or 1.5 to 2 miles behind the lead, regardless of aircraft category. Airbus believes the concept could be applied in commercial aviation before the middle of the coming decade.

“We know the technology is there, it is feasible, and we can find a place [for trailing aircraft] safe from the first aircraft,” said Schaeffer, adding that two nondisclosed airlines are working with Airbus on the project, as are air traffic control organizations.

Operational trials in oceanic airspace are planned for 2021 “with real airlines and traffic management that will define the procedures for such flights,” Schaeffer said. While tests involve only two aircraft, theoretically there’s no limit to the number of aircraft could harvest wake energy in group flights.