Abstract:The Research Aircraft Flight Simulator was designed and manufactured by CAE Inc., which is a very well known internationally Aerospace Company in Aircraft Modeling and Simulation Technologies. This simulator was designed following specific requirements of the Laboratory of Applied Research in Active Controls, Avionics and AeroServoElasticity LARCASE team at ETS in Montreal with the aim to be used for research purposes. The authors are the members of the team. This simulator is equipped with a Flight Dynamics Level D open source code, thus it will be used as a Flight Certified Bench Test with the idea to validate Flight Dynamics Models new codes and methodologies. The Cessna Citation X is the fastest today business aircraft available on the market. However, its engine model is unavailable. For this reason, the authors used this simulator in order to obtain, validate and optimize the main parameters of the engine model such as the time constant and gain variations with altitudes and Mach numbers.