Also, the annotation below the lower object in Fig. 1.11 should, of course, be that "V_p is the projection of V onto the x_b, y_b plane."
Similarly, equation (3.61) is correct only if the derivative C_Z_u is defined analogously to equation (3.51). It is unfortunate that Nelson defines the force coefficient derivatives C_X_u, C_Z_u, and C_T_u in a way that is fundamentally different from the standard definitions of the aerodynamic derivatives C_L_u and C_D_u.