  The influences of the leader in a group of V flight formation are dealt with.
The investigation is focused on the effect of its position and shape on
aerodynamics performances of a given V flight formation. Vortices generated the
wing tip of the leader moves downstream forming a pair of opposite rotating
line vortices. These vortices are generally undesirable because they create a
downwash that increases the induced drag on leaders wing. However, this
downwash is also accompanied by an upwash that can beneficial to the followers
wing flying behind the leaders one, namely a favorable lift for the followers
wing. How much contributions of the leaders wing to the followers wing in the V
formation flight is determined by the strength of tip vortices generated by the
leaders wing which is influenced by its position and shape including incidence
angle, dihedral angle, aspect ratio and taper ratio. The prediction of
aerodynamic performances of the V flight formation including lift, drag and
moment coefficients is numerically performed by solving Navier Stokes equations
with k e turbulence model. The computational domain is defined with multiblock
topology to capture the complex geometry arrangement of the V flight formation.
