MIAMI – With two A350 flying from Toulouse, France to Montreal, Canada, Airbus completes the first long-haul demonstration of formation flight in GAT-regulated transatlantic airspace.

The A350-1000 were greeted at Montreal-Trudeau International Airport (YUL). On the trip, over 6 tons of CO2 emissions were avoided, indicating the possibility of saving more than 5% on long-haul flights, according to a company press release.

On November 9, 2021, two A350 test aircraft, MSN1 and MSN59, took part in a “final demonstration” test flight, with the former serving as the leader and the latter as the follower, taking a cue from the flying pattern of birds.

This bioinspired arrangement could save energy by allowing one plane to provide extra lift to another—if both aircraft can remain stable. If a second aircraft follows the leader at a specific distance and slightly away from the center of the wake, this updraft provides extra lift.

This was made feasible by Airbus flight control technologies, which safely position the follower aircraft in the leading aircraft’s wake updraft, allowing it to minimize engine thrust and fuel consumption. Large migrating birds, such as geese, fly in a characteristic V-shaped pattern, which demonstrates a similar idea.

Pilots from Airbus partner airlines SAS Scandinavian Airlines (SK) and French Bee (BF) were on board as observers for the transatlantic trip. With the help of the DGAC, Airbus and its air traffic management partners and navigation service providers (DSNA, NATS, NAV CANADA, Eurocontrol, and IAA) demonstrated that wake energy retrieval flight technology used in a fello’fly flight can be accomplished without sacrificing safety.

The test also demonstrates how fello’fly operations might greatly improve commercial aircraft’s environmental performance and contribute to the aviation industry’s imminent decarbonization targets.

Geese flying in classic V formation. Ben Mieremet, NOAA photographer. 1995. NOAA Photo Library via Library of Congress.

Airbus fello’fly

Launched in 2019, fello’fly is a flight demonstrator project hosted within Airbus UpNext using biomimicry (the design and production of materials, structures and systems inspired by nature). 

A pair of planes employing fello’fly would take off separately, with the pilots relying on an onboard mechanism to safely bring the two planes together.

Air traffic controllers are currently in charge of maintaining horizontal spacing between two airplanes flying at the same level, according to Giovanni Lenti, the chief of EUROCONTROL’s airspace data maintenance, flight planning, and flow management operations.

However, Lenti told Scientific American a year ago that “to shorten the distance to roughly 1.5 nautical miles (around three kilometers), which is required for fello’fly,” he continues, “new onboard technology, implanted in aircraft avionics, will have to be used by the pilots.”

Lenti stated that stringent rules of operation, combined with specialized software, will help in overcoming such challenges—and in deciding which planes to pair up.

“Fello’fly operations will reduce longitudinal ‘tail to tail’ separation from around 55 kilometers in oceanic airspace to three kilometers,” project leader Nick Macdonald, a senior engineer at Airbus, told the scientific journal.

Airbus Industrie Airbus A350-1041. Photo: Tony Bordelais/Airways

Comments from Airbus

Sabine Klauke, Chief Technical Officer at Airbus declared, “This demonstration flight is a concrete example of our commitment to making our decarbonisation roadmap a reality. It also speaks to how collaboration across the industry will be key to making this happen.”

Klauke added, “We have received a strong level of support for this project from our airline and air traffic partners, plus regulators. The opportunity to get this deployed for passenger aircraft around the middle of this decade is very promising. Imagine the potential if fello’fly was deployed across the industry!”

Airbus intends to use the concept in commercial airline operations by 2025, though it will first only be utilized on oceanic routes to avoid heavy air traffic, as Leni points out.

“At the beginning, it will not be possible to implement it on continental, aircraft-congested routes,” Lenti said a year ago tomorrow. “However, on the ocean, it can work very well—with significant fuel savings for the follower aircraft.”

This Airbus week’s demonstration was the ultimate proof of concept.

Featured image: A350-1000 Fello Fly transatlantic flight. Photo: Airbus