The in-house incompressible flow code 3D-PURLES has been used to simulate the effect of wing aspect ratio on the aerodynamic and transition characteristics at  \(Re=6 \times 10^{4}\) based on the root chord (C) of the wing. The SD7003 rectangular wing non-dimensionalized with respect to the root chord and having different semi aspect ratio (sAR) of 0.25, 0.5 and 1 are considered for this study. The wing aspect ratio is found to significantly affect both the transition phenomenon and the aerodynamic characteristics. The transition onset for wing with lowest sAR is found to be delayed and having a longer transition zone. The aerodynamic characteristics of this wing in terms of the stall angle, maximum lift coefficient and drag coefficient are found to be superior making it a suitable candidate for MAV applications operating at this low Reynolds number regime. The influence of Reynolds number in the low Re regime on the performance of the SD7003 rectangular wing with 0.25 a semi aspect ratio is also discussed in this paper.