Investigation of High-Angle-of-Attack Maneuver-Limiting Factors. Part I. Analysis and Simulation

摘要

The high-angle-of-attack, low-speed stall/departure characteristics of the F-4J and F-14A are analyzed, using a six-degree-of-freedom mathematical model with nonlinear aerodynamics. Cause-effect relationships are investigated for maneuver limiting factors including wing rock, nose slice, and rolling departures. Cross-derivatives of L alpha, N alpha, and M beta alter key transfer function parameters. A piloted simulation validates analytic predictions and demonstrates that departure warning, susceptibility, and severity are strongly influenced by the static cross-derivatives. A connection between roll numerator parameter values and pilot perception of departure susceptibility and severity is identified. Potential modifications for the high AOA sections of the MIL-F-8785B Flying Qualities Specification are proposed: a criterion for the real part of the roll numerator root, further recommendations for minimizing departure susceptibility and certain sideslip influences, and a flying quality rating form for assessing departure and recovery characteristics. Part I, Analysis and Simulation, presents a summary of the complete investigation and results. Part II, Piloted Simulation Assessment of Bihrle Departure Criteria, presents a detailed comparison of analytical prediction and piloted simulation results for a specific set of programmed control deflections. Part III, Appendices -- Aerodynamic Models, contains the detailed aerodynamic models employed in the F-4J and F-14A high-angle-of-attack analysis and validation and the equations of motion, aerodynamic models, control system configurations, etc., employed in the piloted simulation. (Author)