Fig. 2. Resultant forces and moments relative to the body. (A) Illustration of the six degrees of body motion: the directional components (thrust, lift and sideslip) and the moments (roll, yaw and pitch). The projection of the aerodynamic force vector (F_N) onto each of the three rectangular axes constitutes its contribution to thrust (F_x), lift (F_y) and sideslip (F_z). The moment depends on the position vector r and the force vector F_N as described in the text. (B) Simplified sideview of A. If the sideslip component of force is negligible, lift and thrust depend primarily on the magnitude (F_N) and inclination (_F) of the force vector as the wing moves through the stroke (blue dots denote changes in position).