In this study. a formulation has been proposed to calculate the pressure on wall and determine the angle of failure wedge based on limit equilibrium method. The mentioned formulation is capable of calculating active pressure coefficient. culmination of forces in failure surface. https://www.diegojavierfares.com/flash-pick-Mooney-M20J-1979-1980-Pilot-s-Operating-Handbook-part-1223-great-buy/