A multidisciplinary computational investigation of buffet load alleviation of the vertical tail of full F/A-18 aircraft is conducted and presented. Alleviation of the vertical tail buffeting is achieved using trapezoidal streamwise LEX fences. The LEX fences are mounted over the wing LEX to reconstruct the vortical flow over the aircraft. Multidisciplinary analysis modules for the fluid dynamics, structure dynamics, fluid-structure interfacing, and grid motion are integrated into a multidisciplinary computing environment that controls the synchronization of the temporal execution of the analysis modules. The aerodynamic flowfield is solved using the full Navier-Stokes equations. The structure dynamic responses of the vertical tail are computed using direct finite-element analysis. The fluid-structure interfacing is modeled using conservative and consistent interfacing module. A transfinite interpolation algorithm is used to deform the computational grid dynamically to accommodate the deformed shape of the vertical tail. The investigation is conducted over wide range of high angles of attack at Mach number of 0.243 and Reynolds number of 11 million. The LEX fences shift the power peaks of the buffet pressure and root bending moment into higher angles of attack. The LEX fences also reduce the RMS of differential pressure and RMS of root bending moment. At 30° angle of attack, the acceleration power of the vertical tail tip is reduced by up to 38% at first bending mode, and by up to 24% at first torsion mode. However, the effectiveness of the LEX fences for buffet alleviation reduced at very high angles of attack.