 By taking advantage of wake updraft like migrating birds (biomimicry), Airbus believes an aircraft can save 5-10% of fuel by flying behind the preceding one.After A380s tests showing 12% savings, it launched its 'fello'fly' project in November 2019 for test flights in 2020 with two A350s, before transatlantic flight trials with airlines in 2021.Certification for shorter separation is enabled by ADS-B in oceanic airspace, and the only modification required would be flight control systems software.