The term simulator fidelity has become enormously important in the scope of simulation research, when assessing training efficiency and the transfer of training to real flight. It is defined as the degree to which a flight simulator matches the characteristics of the real aircraft. Objective simulator fidelity provides an engineering standard, by attacking the fidelity problem with comparison of simulator and the actual flight over some quantitative measures. Research flight simulators encompass some differences from commercial flight simulators. They require high flexibility and versatility concerning the cockpit layout and visual and motion systems, as well as flight simulation models. It should be easy to modify the flight simulation model or other software and hardware components of the simulator. To support this, there is a need for a flexible automated test methodology, in order to determine the fidelity of the most relevant simulator subsystems, since they are often modified during the life cycle of the simulator. This methodology not only shall support automated execution but also enable automated generation of the test cases which are subject to change as well as simulator components. The Institute of Flight Systems (FT) at the German Aerospace Center (DLR) has a reconfigurable flight simulator, the Air Vehicle Simulator (AVES), for research of rotorcraft and fixed-wing aircraft. The study reported in this paper adopts a Model Based Testing approach to tackle the high flexibility requirement of AVES. The outcome of the paper is a metamodel for model-based objective flight simulator evaluation. Metamodeling has been carried out in two levels. An Experimental Frame Ontology (EFO) has been developed adopting experimental frames from Discrete Event System Specification (DEVS), and as an upper ontology to specify a formal structure for a simulation test. Then in Objective Fidelity Evaluation Ontology (OFEO) that builds upon EFO, domain specific meta-test definitions are captured.