This work presents a technique for analytically determining the trim conditions of a fixed wing aircraft from the parameters of its nonlinear mathematical model. Specifically, the elevator, aileron, and rudder deflections are determined in addition to the necessary thrust force and resulting angle of attack and sideslip angles for this flight condition. The technique is demonstrated using three established nonlinear aircraft models: NAVION, F104-A, and Convair 880. These aircraft were selected to represent three different types of fixed wing aircraft: general aviation, fighter jet, and passenger jet, respectively. The results from these aircraft indicate the validity and usefulness of this technique for simulation and control experiments.