Flexoelectric properties are evident in experiments preformed with hybrid aligned nematic. In this article, the flexoelectric effect in a hybrid aligned nematic in-plane switching liquid-crystal cell is investigated. The equations for the distribution of the liquid-crystal director and the expression of critical voltage in the one-constant approximation are obtained. The results of computer simulation show that the value of angle phi exceeds 90 degrees and closes to 180 degrees between the bottom substrate and the mid-layer.