V formation

Eurasian Cranes in a V formation.

This article is about the flight formation of birds, For the military aircraft formation, see Vic formation

A V formation (sometimes called a skein) is the symmetric V-shaped flight formation of flights of geese, ducks, and other migratory birds. V formations also improve the fuel efficiency of aircraft and are used on military flight missions.

Aerodynamics

The V formation greatly boosts the efficiency and range of flying birds, particularly over long migratory routes.[1] All the birds except the first fly in the upwash from the wingtip vortices of the bird ahead. The upwash assists each bird in supporting its own weight in flight, in the same way a glider can climb or maintain height indefinitely in rising air. In a V formation of 25 members, each bird can achieve a reduction of induced drag by up to 65% and as a result increase their range by 71%.[2] The birds flying at the tips and at the front are rotated in a timely cyclical fashion to spread flight fatigue equally among the flock members. Canada geese are a common example demonstrating the V formation.

Military flight missions

IRIAF F-4 Phantoms in a V formation over 6th TAB of Iran

The "V", or "Vic" formation is a basic flight formation for military aircraft in many air forces.

The Vic formation is also common in ceremonial flyovers and airshow flights.

Air Mobility Command, which accounts for 20 percent of federal fuel usage, is experimenting with autopilot changes to find the best tradeoff between the reduced drag of 'vortex surfing' and the resulting 'ride qualities' of flying through another aircraft's wake.[3][4]

See also

References

Bibliography