iSUMMARYThis report and a previous report, NASA TM 107601, "Simulation Model of a Twin-Tail,High Performance Airplane," (ref. 1.0), document the aircraft model and computer programwhich form the nonlinear, six degree-of-freedom, batch simulation of the High Alpha ResearchVehicle (HARV), a highly modified F/A-18. Reference 1.0 describes the f18bas simulation ofa basic F/A-18 modified with a hypothetical thrust-vectoring system. This report describesmodifications to that simulation to form the simulation of the HARV called f18harv.The HARV is an F/A-18 airplane modified to incorporate a multi-axis thrust-vectoring sys-tem for augmented pitch and yaw control power and actuated forebody strakes for enhancedaerodynamic yaw control power. The HARV is used in NASA's High Alpha TechnologyProgram (HATP) to conduct flight research in advanced control effectors, advanced controllaw design methodologies, and flight dynamics issues at high angles of attack. An example ofadvanced control effector research is the Actuated Nose Strakes for Enhanced Rolling(ANSER) experiment.The f18harv simulation is written in Advanced Continuous Simulation Language (ACSL)and FORTRAN languages. Significant modifications to the f18bas simulation to form f18harvinclude implementation of the HARV aerodynamic database to account for thrust-vectoringinduced effects, implementation of a different engine model, implementation of a model of theHARV thrust-vectoring system, addition of high-fidelity sensor models, addition of theaerodynamic database for ANSER control devices, and addition of control surface actuatormodel enhancements. Other modifications such as weight and balance updates were requiredto match the performance of the F/A-18 HARV aircraft more closely. The resulting simulationwas used in the design of advanced HARV control laws, which were implemented in thesimulation.