A study has been conducted to determine how well the USM3D unstructured Euler solver can be utilized to predict the flow over the High Speed Research (HSR) Reference H configuration with an ultimate goal of prediction of Sting interference so after body closure effects may be evaluated. This study has shown that the code can be used to predict the interference effects of a lower mounted blade sting with a high degree of confidence. It has been shown that wing and fuselage pressures, both levels and trends, can be predicted well. Force and moment levels are not predicted well but experimental trends are predicted. Based upon this, predicted force and moment increments are assumed to be predicted accurately. Deflection of the horizontal tail was found to cause a non-linear increment from the non-deflected sting interference effects.Londenberg, W. KellyLangley Research CenterAFTERBODIES; CLOSURES; AERODYNAMIC CONFIGURATIONS; HIGH SPEED; UNSTRUCTURED GRIDS (MATHEMATICS); EULER EQUATIONS OF MOTION; WINGS; FUSELAGES; HORIZONTAL TAIL SURFACES; COMPUTER PROGRAMS; TRENDS; AERODYNAMIC INTERFERENCE...