The analytical expressions for the performance of airborne optical com munication systems under the combined influence of atmospheric turbulence and aero-optic e ffects are presented in this paper.The atmospheric turbulence is modeled by the exponentia ted Weibull (EW) distribution.The closed-form expressions for average bit error rate (BER),probability of fade and average channel capacity are derived based on a Meijer′s G function.These sys tem performances are evaluated under the influence of various flight altitudes and propagation di stances.The effects of aperture averaging on the system performance are studied as well.Our results demonstrate that the aperture averaging technique can significantly improve the system performanc e under turbulence and aero-optics effects.Furthermore,this work is helpful for the c ompensation technique of system performance on airborne optical communication sy stem.