Fello’fly borrows from birds to improve aircraft flight efficiency
Airbus is working on a new demonstrator project to test the idea that two commercial aircraft flying in tandem can boost flight efficiency while reducing emissions. Based on the technique used by flocks of birds to keep their avian members aloft more efficiently, the fello'fly project will examine how trailing aircraft can hitch a lift in the wake of the leader.
Birds fly in formation for a lot of reasons, but one important one is that it's a lot easier. When birds fly in a "V" formation, the birds following down the line time their wingbeats to catch the uplift eddies generated by their neighbor in front. And if two birds are flying in tandem, the trailing bird reverses its flapping to take advantage of the lift of the leader's wake.
By mimicking this technique, Airbus' fello'fly demonstrator project hopes to improve commercial aircraft efficiency on long-haul flights. As an airplane flies, a lot of the energy it produces is lost in its wake. By positioning itself on the wake's updraft, the following aircraft can gain lift, allowing it to cut back on engine thrust, which Airbus says can reduce fuel consumption by five to 10 percent, resulting in a reduction in emissions as well.
In theory, this should work, but Airbus says there are a number of technical hurdles to clear. This means that fello'fly needs to work on developing pilot assist systems to help keep the aircraft positioned in the updraft at the right distance and a steady altitude. To do this, Airbus is working with airlines and Air Traffic Control (ATC) providers to sort out the needs and solutions for fello'fly operations, with flight tests involving two of its A350 aircraft set to commence in 2020.