WHY DO BIRDS FLY IN FORMATION?

• First, it conserves their energy. Each bird flies slightly above the bird in front of him, resulting in a reduction of wind resistance. The birds take turns being in the front, falling back when they get tired. In this way, the birds can fly for a long time before they stop for rest.
• Secondly, it is very easy to keep track of all the birds when flying in V formation. Fighter pilots often use this formation for the same reason.

Birds being the undisputed masters of aerodynamics, no matter how many supercomputers and wind tunnels scientists throw at solving flight’s thorny calculations, they’ll never match the perfection of our feathery friends!

Before we dwell any further,here are a few concepts to be understood :

• WING TIP VORTICES : Wingtip vortices  are circular patterns of rotating air left behind a wing as it generates lift. One wingtip vortex trails from the tip of each wing. Wingtip vortices are sometimes named trailing or lift-induced vortices  because they also occur at points other than at the wing tips

• WAKE TURBULENCE : Wake turbulence is a disturbance in the atmosphere that forms behind an aircraft as it passes through the air. It includes various components, the most important of which are wingtip vortices and jetwash. Wake turbulence is especially hazardous in the region behind an aircraft in the takeoff or landing phases of flight.

THIS BEGS THE QUESTION–

Could passenger planes begin flying in formation  to draft each other’s wingtip vortex effects?

One Airbus-based startup concept thinks so. The concept uses a formation idea inspired by birds, who commute north to south and back in large V shapes to capitalize on the updraft generated by the birds in front.

Those formations have provided the inspiration for researchers at Airbus UpNext-the aircraft manufacturer’s future-flight demonstration and technology incubator.

Scientists began to understand that birds were increasing aerodynamic efficiencies by flying in close formation, taking advantage of the changed airflow in each bird’s wake.With that in mind, the Airbus fello’fly flight demonstration project would fly two large commercial aircraft in formation, looking to mimic the energy savings of our feathered friends.

In the concept pushed by the Airbus incubator, appropriately named “fello’fly,” planes line up over a mile apart, which is still close enough to benefit from the wingtip vortices generated on either side of the lead plane.

Pilots are taught to avoid wake turbulence, as it will be in the fello’fly demonstration. Pilots are also trained to not fly into the vortex of a preceding aircraft.

They would be 1 1/2 to 2 nautical miles away from the leading aircraft, and slightly offset, meaning they would be on the side of the vortex. It’s no longer the vortex, it would be the smooth current of rotating air which is next to the vortex, and the updraft of this air would be utilised.

Taking advantage of the free lift in this updraft of air is called “wake-energy retrieval.” Reports suggest upcoming flight trials using two A350s could prove that on long-haul flights, fuel savings of between 5% and 10% may be achieved, which is an enormous number.

SIMPLY PUT–

To ride the wave without facing adverse outcomes, fello’fly planes would use an updraft of air that’s just outside the tube of wingtip vortex. That means careful planning and formation that’s more offset to make sure the planes truly follow in the updraft instead of the vortex. The updraft they want to ride is invisible, but basically, the planes will bodysurf in the most advantageous portion of the full spread of wake from the lead plane.

DEVELOPMENTS SO FAR

Building on test flights in 2016 with an Airbus A380 megajet and A350-900 wide-body jetliner, fello’fly hopes to demonstrate and quantify the aerodynamic efficiencies while developing in-flight operational procedures.Initial flight testing with two A350s began in March 2020. The program would be expanded this year to include the involvement of Frenchbee and SAS airlines, along with air traffic control and air navigation service providers from France, the UK, and Europe.

SOURCE(S)

• https://www.loc.gov/everyday-mysteries/zoology/item/why-do-geese-fly-in-a-v/#:~:text=First%2C%20it%20conserves%20their%20energy,back%20when%20they%20get%20tired.&text=The%20second%20benefit%20to%20the,every%20bird%20in%20the%20group.
• https://edition.cnn.com/travel/article/airbus-formation-flight/index.html
• en.wikipedia.org
• https://www.popularmechanics.com/flight/airlines/a34054051/airliners-fly-in-formation-birds-airbus/
• COVER PIC COURTESY : https://edition.cnn.com/travel/article/airbus-formation-flight/index.html