Real time aircraft simulation using J-MASS

McDonnell Douglas Aerospace (MDA) has developed a six degree-of-freedom (DOF) aircraft model that is suitable for use at various levels of simulation, from manned to interactive to all digital. The model is based on the performance of the aircraft being simulated and is used for development of flying qualities criteria or for existing simulations where high angle of attack, take-off's and landings are not required. The model is ideal for use in air combat studies where the exact performance of the model is known and real time operation is required (20 Hertz update rate). The original aircraft model was written in FORTRAN and is still in use. When a manned simulation is not needed, digital pilot logic provides stick and throttle inputs to the model. Available maneuvers include lever flight, sustained turns, waypoint following and others. This model has been rewritten in Ada and re-engineered to add additional capabilities. The model has become more object oriented, and still updates in real-time. In addition, an Ada interface has been added to the model so it is compliant with the Joint Modeling and Simulation System (J-MASS).