Program SOM-LA (Seat/Occupant Model - Light Aircraft) has been developed for use in evaluating the crashworthiness of aircraft seats and restraint systems. It combines a three-dimensional dynamic model of the human body with a finite element model of the seat structure. The seat analysis has the capability to model large displacements, nonlinear material behavior, local buckling, and various internal releases for beam elements. The final phase of validation included simulation of dynamic tests of production general aviation seats. Model predictions are compared with test data for one of these seats.