A computational study on the nonequilibrium turbulence modeling effects for the prediction of the light stall phenomenon has been done for the NACA0012 airfoil. For this, an unsteady thin-layer Navier-Stokes solver was developed that is capable of solving the flowfield around an airfoil undergoing unsteady harmonic motion. In the program, the Baldwin-Lomax and Cebeci-Smith turbulence models were used as baseline models, and the Johnson-King turbulence model was used to study the nonequilibrium effects. It was found that the nonequilibrium effects are important for the prediction of the light stall, and only the Johnson-King model yields light stall hysteresis loop that is similar to the experiment. It was also found that the wind-tunnel wall effects are important, and a mean angle-of-attack increase in the computation was necessary to yield a better agreement with the experiment.