Agent-Based Simulation of Off-Nominal Conditions During a Spiral Descent (NextGen Vehicle NRA) Vitali Volovoi * and Giorgio Calanni Fraccone † Georgia Institute of Technology, Atlanta, GA, 30332, USA Alfredo E. Col´on ‡ and Matthew Hedrick § CSSI Inc., Washington, DC, 20024, USA Randall Kelley Sensis Corporation, Washington, DC, 20024, USA The goal of this study is to provide quantitative simulation-based models corresponding to representative off-nominal conditions that pose credible hazards specific to new types of vehicles operating under new operational procedures within the Next Generation air Trans- portation System (NextGen). These models are aimed at complementing a comprehensive, but relatively high-level and mostly qualitative hazard assessment of the new vehicles op- erating within NextGen, by illuminating a path toward more detailed and quantitative safety analysis which will be helpful in the design of new vehicles and their operational procedures, and in developing recommendations for any appropriate new standards and regulatory guidance. Nomenclature z Altitude ψ Heading φ Bank angle γ Flight path angle V I Inertial speed V True airspeed V C Calibrated airspeed n Load factor R Turn Radius R min Minimum allowed turn radius W Wind vector velocity W N , W E , W D Wind velocity components in the NED frame ˆ W Measured wind velocity α Wind direction in the NE plane κ Amplification factor for wind speed τ Pilot’s response time delay P E Probability of event E’s occurrence N (µ,σ) Normal distribution * Assistant Professor, School of Aerospace Engineering, 270 Ferst Dr., AIAA Senior Member. † Postdoctoral Fellow, School of Aerospace Engineering, 270 Ferst Dr., AIAA Member. ‡ Senior Engineer, 400 Virginia Ave., AIAA Member § Aviation Systems Analyst, 400 Virginia Ave., AIAA Member 1 of 12 American Institute of Aeronautics and Astronautics