A Scale Adaptive Simulation (SAS) is implemented with the Spalart-Allmaras (SA) turbulence model to evaluate its capability for flows with massive separation. A subsonic flat plate case is validated and the results are compared with SA and other hybrid turbulence models. The Mean Stress Depletion (MSD) problem, aroused in the case of the Detached-Eddy Simulation (DES97), is not observed with the SAS turbulence model under ambiguous grid. Subsequently, NACA 0012 airfoil is investigated for post-stall regime and predicted aerodynamics performance is compared with the experimental, URANS and IDDES results. The predicted lift and drag coefficients using the SAS and IDDES agree well with the experiment, significantly more accurate than the results of URANS. Apart from these quantitative results, the turbulent flow structures obtained with hybrid turbulence models reveal more details of the small structures.