Flying like Geese: Inside the trial taking inspiration from migratory birds

In aviation, inspiration sometimes comes from unexpected places. In this case, it comes from nature itself.

Migratory birds have long mastered the art of travelling vast distances efficiently. By flying in formation, they conserve energy and share the workload across the flock.

Now aviation is exploring how similar principles could help aircraft reduce fuel burn and emissions through Project Geese, a collaborative research initiative with SESAR exploring formation flying for commercial aircraft.

In our latest episode of Altitude, host Russell Porter spoke with experts from across the aviation ecosystem about how the concept works, what the recent flight trials achieved, and what might come next.

Joining the discussion were Laura Montironi from Airbus, Captain Kevin May from Delta Air Lines, and Andreas Petrikat from NATS.

Learning from nature

Project Geese explores a concept known as Wake Energy Retrieval (WER). The idea is simple in principle. One aircraft, known as the follower, flies behind another aircraft, the leader, positioned to take advantage of the upward airflow created by the leader’s wake.

“The follower aircraft can surf the updraft generated by the leader,” explains Laura. “That allows it to reduce engine thrust, saving fuel and cutting emissions.”

Just as geese fly in a loose V formation to conserve energy during long journeys, aircraft could fly in paired formations across oceans. The follower aircraft would sit roughly one to two nautical miles behind the leader, positioned to capture the aerodynamic benefit while maintaining a smooth ride for passengers.

This is a classic example of biomimicry, borrowing ideas from nature to solve complex engineering challenges. The concept was popularised by scientist Janine Benyus in her 1997 book.

“For now, we are focusing on two aircraft,” Laura says. “Birds do it in larger formations, but from an operational perspective starting with pairs keeps the concept manageable.”

From concept to reality

Airbus has been studying formation flying for years through its fello’fly programme, which focuses on the technology aircraft need onboard to safely fly in formation.

“We realised quickly that aircraft technology alone was not enough,” Montironi says. “We also need the support of air traffic control, airlines, dispatchers and regulators.”

The project moved from theory to practice during flight trials last year, when aircraft from Delta Air Lines, Virgin Atlantic, Air France and French Bee coordinated rendezvous flights over the Atlantic.

For pilots, the experience was reassuringly familiar.

“Operationally, there is nothing dramatically different from what we do every day,” says Captain Kevin May, an Airbus A350 captain with Delta. “We were essentially performing a planned trajectory change, something aircraft already do regularly. The difference was that we were doing it intentionally, with another aircraft.”

Behind the scenes, however, coordination was extensive. Airbus developed a pairing assistance tool that analyses real-time flight and traffic data to identify potential aircraft pairings and calculate whether the rendezvous would deliver a net fuel saving after any rerouting.

Making two aircraft meet at exactly the right place and time over the Atlantic requires careful planning.

“It was like an orchestra,” says Captain May. “Everybody was playing from the same sheet of music.”

Months of preparation went into the trials. Teams worked with airline dispatchers, air traffic control specialists and engineers to ensure every aspect of the operation was understood and safe.

Air traffic controllers also play a critical role by coordinating the aircraft responses and facilitating the trajectory change.

“This project really shows aviation collaboration at its best,” says NATS’ Andreas Petrikat. “Airlines, manufacturers, controllers and regulators all working together to make something like this possible.”

You can watch the full episode of Altitude on YouTube, or listen wherever you get your podcasts.

The SESAR 3 GEESE project is funded by the EU under the Horizon Europe programme, [grant number 101114611]. UK participant NATS receives funding from UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee [grant number 10091272].