Power of the wingbeat: modelling the effects of flapping wings in vertebrate flight by Heerenbrink, M, Johansson, L, Hedenström, A

“…Flying animals flap their wings to produce thrust. Adopting the fixed wing flight model implicitly incorporates the effects of wing flapping in the coefficients. …”

Aerodynamics of aerofoil sections measured on a free-flying bird by Carruthers, A, Walker, S, Thomas, A, Taylor, G

“…Birds are adapted to a wide range of flight conditions, from steady fixed-wing glides to high angle of attack manoeuvres involving unsteady separated flows. …”

Animal flight dynamics II. Longitudinal stability in flapping flight. by Taylor, G, Thomas, A

“…Flapping animals, like fixed wing aircraft, are predicted to be stable in forward flight if the mean flight force acts above and/or behind the centre of gravity. …”