The intensive design optimization of airframes has the effect of decreasing the structural stiffness, which can induce large deformations. Such changes can have a significant effect on the flight loads as well as the trimming configuration of the aircraft. Iterative solutions to approach this problem have been proposed in literature, coupling nonlinear structural solution methods with linear aerodynamics. In this paper, a modified iterative methodology is proposed, which includes the downwash effect of the aerodynamic twist into the solution sequence to improve the fidelity of the calculated aerodynamic loads compared to the existing method. A case study is presented to investigate the differences in the wing loads of interest and trimming configuration when the effect of geometric nonlinearities are included in the static aeroelastic analysis, as the mass and stiffness is varied. Increases of 20%, 13% and 30% are observed in the out of plane bending moment, out of plane shear force and torque for the most flexible variant of the airframe considered. Additionally, significant differences are observed in the corresponding trimming configuration, with changes of -12% and -8% in the trimmed angle of attack and elevator deflection respectively.