A Method of Standardizing Takeoff Performance Data using Modeling and Simulation

Existing methods of correcting takeoff distance data to reference conditions rely on analytical or empirical equations that are limited to small incremental corrections for a small number of factors. An alternate method of standardizing takeoff performance data is presented here that uses modeling and simulation to correct for the effects of non-standard ambient air temperature, pressure altitude, wind, runway slope, aircraft gross weight, pilot technique, and numerous other factors. The method uses a two-degree-of-freedom takeoff simulation to calculate corrections to the test-day measured distances and airspeeds at rotation, liftoff, and 50 feet above ground level. Since the simulation is physics-based, it can be used to make large corrections and extrapolations over the full range of conditions for which its component models are valid. The simulation uses models of the aerodynamic, propulsive, and rolling resistance forces that are validated or updated based on flight test results. Two methods of modeling pilot rotation and pitch attitude capture techniques are implemented. Application of the modeling and simulation method is illustrated using flight test data from a four-engine turboprop tactical transport aircraft.