Motor

Box

Lamello

Building

Prototypes

Spatial

Alignment

http://www.businessinsider.com/why-bird-fly-in-a-v-formation-2014-1
http://news.softpedia.com/news/Why-Do-Birds-Fly-in-V-Formation-52785.shtml

Upwash exploitation and downwash avoidance by flap phasing in ibis formation flight

Steven J. Portugal, Tatjana Y. Hubel, Johannes Fritz, Stefanie Heese, Daniela Trobe, Bernhard Voelkl, Stephen Hailes, Alan M. Wilson & James R. Usherwood

Nature 505, 399–402 (16 January 2014) doi:10.1038/nature12939

Received 30 May 2013, Accepted 03 December 2013, Published online 15 January 2014 

Many species travel in highly organized groups. The most quoted function of these configurations is to reduce energy expenditure and enhance locomotor performance of individuals in the assemblage. The distinctive V formation of bird flocks has long intrigued researchers and continues to attract both scientific and popular attention. The well-held belief is that such aggregations give an energetic benefit for those birds that are flying behind and to one side of another bird through using the regions of upwash generated by the wings of the preceding bird, although a definitive account of the aerodynamic implications of these formations has remained elusive. 

Here we show that individuals of northern bald ibises (Geronticus eremita) flying in a V flock position themselves in aerodynamically optimum positions, in that they agree with theoretical aerodynamic predictions. Furthermore, we demonstrate that birds show wingtip path coherence when flying in V positions, flapping spatially in phase and thus enabling upwash capture to be maximized throughout the entire flap cycle. In contrast, when birds fly immediately behind another bird—in a streamwise position—there is no wingtip path coherence; the wing-beats are in spatial anti-phase. This could potentially reduce the adverse effects of downwash for the following bird. These aerodynamic accomplishments were previously not thought possible for birds because of the complex flight dynamics and sensory feedback that would be required to perform such a feat. 

We conclude that the intricate mechanisms involved in V formation flight indicate awareness of the spatial wake structures of nearby flock-mates, and remarkable ability either to sense or predict it. We suggest that birds in V formation have phasing strategies to cope with the dynamic wakes produced by flapping wings.

http://www.nature.com/nature/journal/v505/n7483/full/nature12939.html

Kinematics

Wing kinematics differ depending upon a bird's wing design and flight speed. (A) Birds with pointed, high-aspect ratio wings such as the pigeon Columba livia transition from tip-reversal upstrokes during slow flight to feathered upstrokes at intermediate speeds and a swept-wing upstroke during fast flight. (B) Birds with rounded, low-aspect ratio wings such as the black-billed magpie Pica hudsonica use a flexed upstroke at all flight speeds. Shown are wingtip (filled circles) and wrist (open circles) paths in dorsal and lateral view

http://jeb.biologists.org/content/210/18/3135/F3.expansion.html

Slow motion

Students in David Lentink's Biomechanics of Flight class use a special high-speed camera to discover new, never-before-seen intricacies of flight. Students use the slow motion video to analyze flight parameters for future applications.