This paper discusses the procedure used to improve the flight simulation fidelity of the LAMPS MK III Operational Flight Trainer. Early involvement of customer and airframe manufacturer personnel and their continued support throughout the simulator development program had a significant influence on the flight fidelity of the delivered training device. Automated performance evaluation and sensitivity analysis tools were developed to identify and isolate simulator flight performance problems. These tools and the techniques used to modify simulator flight performance characteristics to agree more closely with aircraft flight test results are described in this paper, along with examples of typical performance improvements.