A trajectory specification method for a flapping-wing flying robot exhibiting a novel dynamical model than other types of micro aerial vehicles such as quadrotors and airplanes is presented. The desired trajectory is first defined as a vector-valued, differentiable parametric curve of the form f : R^R → R^R. The velocity vector at any point of the trajectory is the same as the unit tangent vector obtained using parametric differentiation. The acquired unit tangent vector is subsequently expressed in quaternion form and nominal values for the pitch and yaw angles at every point of the trajectory are determined. Finally, the feed-forward trajectory is specified as a function of the input control variables (δr, δe) of the flapping wing flying robot. At the same time, the feasibility of a specified trajectory is verified so that there are no violations of intrinsic constraints. Both two and three dimensional flight trajectories are simulated for exemplification. Simulation results are compared to real sensor data, thus verifying the procedure.