thumb|[[Eurasian cranes in a V formation]]

thumb|(video) Birds flying in V formation

A V formation is a symmetric V- or chevron-shaped (two sides of a triangle) flight formation. In nature, it occurs among geese, swans, ducks, and other migratory birds while in human aviation it is used mostly in military aviation, air shows, and occasionally commercial aviation.

Flying in the V formation is thought by some to improve energy efficiency. Others hypothesize that it is the formation that most reliably allows a flock of large birds to fly very close together without any member of the flock being disturbed by the vortices of a bird flying ahead, while at the same time having the most favorable conditions for the optical perceptions to maintain the flight formation. In a 2001 Nature study, researchers used trackers on pelicans, trained to fly behind a motor boat. They found that pelicans flying alone had higher heart rate and flapped their wings more frequently compared to those flying at the same speed in V formation.

alt=Birds V formation photo by Inu Etc|thumb|Migratory birds in V formation

Flight characteristics

In a group of ibises, some birds preferred to fly at the left, some at the right, and some at the center. in V formation.

Flying in V formation is not only about position but also about the timing of flapping. The birds behind will sync with the flapping pattern of the leading bird to follow the trail of upwash left by the bird at front. The goal of this program was to save a sustained 10 percent of fuel, and experimental data suggested that as high as 15 percent could be achieved. Such fuel reduction can also reduce the amount of pollution released into the environment.

Commercial flight

Airbus has made efforts to reduce fuel consumption in commercial aviation through its fello’fly project, where two commercial aircraft fly in a V formation. Since large aircraft at high speed generate immense vortices at their wings, two aircraft will fly approximately 1.5 to 2 miles apart, near the smooth current of updraft. Thus, significant fuel can be saved without compromising passenger comfort.

Test flights were done using two AS350 Écureuil helicopters, and the results showed that 5 percent to 10 percent of fuel can be reduced for the second aircraft per trip. This percentage per flight means several tons of jet fuel and carbon dioxide emissions.

  • Geese
  • Swans
  • Gulls
  • Cranes
  • Pelicans
  • Cormorants
  • Ibises
  • Ducks

Past studies and findings

  • Wieselsberger (1914): An aerodynamicist who was the first to suggest that a formation may give birds an aerodynamic advantage by exploiting the wingtip vortices. He proposed that birds flying in a V formation make use of the upwash of neighboring birds to reduce induced drag, and hence conserve energy in flight.
  • Hamilton (1967): Posited that the staggered formation provides an advantage for visual communication with neighboring birds. At the same time, it also provides a clear viewing field during flight.

References

Migrating birds real flight V-formation spatial configuration. Real Dataset from North German bird migration photo).