Airbus will in 2020 begin flight tests of a new fuel-saving concept that will allow large passenger jets to gain “free lift” by flying in the smooth updraft created by the vortex of a preceding aircraft.
Airbus will in 2020 begin flight tests of a new fuel-saving concept that will allow large passenger jets to gain “free lift” by flying in the smooth updraft created by the vortex of a preceding aircraft.
This can be achieved through modifications to flight-control software rather than the installation of new sensors, says Dr Sandra Bour Schaeffer, chief executive of Airbus Upnext, a research arm of the airframer.
Airbus
Airbus refers to the concept as wake energy retrieval and says it was inspired by the way geese fly: “Birds in formation use the updraft from the previous bird to use less energy,” she says. “Those following the first one get free lift.”
Wake energy generated by aircraft is currently lost, Bour Schaeffer says, but she believes that under the initiative, called “fello’fly”, a trailing jet could harness the “smooth updrafts”.
A previous trial flight using a pair of A380s operating around 1.6nm (3km) apart showed a fuel consumption saving of 10%, says Bour Schaeffer; Airbus anticipates operational savings of 5-10% on a typical Paris-New York flight will be achievable.
“The air is quite smooth and easy to ride and does not impact the comfort of passengers,” she says. “There is huge potential in it.”
A system of cameras and Lidar sensors were used to identify the vortices and establish the correct separation distance between aircraft.
Two undisclosed airline partners have been recruited for the flight trials next year. These will be conducted with A350s on transatlantic operations.
Airbus believes that should the concept be successfully validated then service entry could be achieved before the mid-2020s.
However, it stresses that air traffic management providers and regulators will also need to get behind the initiative in order to ensure a successful real-world application. In particular, current separation minima would need to be reviewed, says Bour Schaeffer.
Although Airbus will launch the initiative with its aircraft, fello’fly is “platform agnostic” and could be applied on jets from other manufacturers.
