Nonlinear Flying Qualities Criteria for PIO Prediction using Global Nonlinear Analysis

Global nonlinear analysis of pilot-aircraft system using the bifurcation and chaos theory methodology (BACTM) is proposed as a general framework for developing nonlinear flying qualities criteria for prefiction of Pilot Induced Oscillations (PIO). The proposed methodology is expected to augment existing criteria and benefit the current thrust in mission-oriented fluing qualities research in two ways: (1) Identification of pilot-aircraft characteristics that lead to category II and category III PIO and (2) Refinement of existing criteria and development of new nonlinear criteria for prediction. BACTM is a multivariable time domain technique for computing stable/unstable flight regimes, bifurcation and jump surfaces, limit cycles and other nonlinear phenomena. The proposed work involves application of BACTM to a selected aircraft, identification of global characteristics that indicate PIO potential and development of nonlinear prediction criteria. Lockheed Martin tactical Aircraft Systems (LMTAS) will provide technicaland commercialization support during all phases of the SBIR effort, incuding mission definition and acquisition of aircrft data needed to perform BACTM analysis.