Contact NASA-Langley: Gary Fleming Email: g.a.fleming@larc.nasa

1. Long-term vision Aeroelastic characterization is vital to future aerospace vehicle design, but is costly, non-routine, and requires significant setup and aircraft adaptations. Recently a wind tunnel technique has been adapted for in-flight without these limitations Complete time-histories of aerodynamically induced twist and deflection from take-off to landing, with next-day delivery of reduced data In-Flight Aeroelastic Measurement Technique Non-Metric positioning system Three-Axis accelerometer system Force Positioning System Balance (Inside Fixture) Weight Application Rod • Accomplishments • In-flight measurements on • F/A-18 Research aircraft • M = 0.95 at 15,000 ft. • Spanwise wing bending • Time-histories of maneuver • Methodology • Extract image coordinates • Manual • Centroids • Edges or lines • Digital image correlation • Transform from image to object • Subtract out reference condition • Attributes • Robust • Low cost* • Flexible to measurement needs* • High precision possible • Simple targeting* • Time-histories • (* better than current methods) • Future capabilities • Entire flight sequence • No special targets • Control surface geometry NASA Langley Research Center and NASA Dryden Flight Research Center (within Active Aeroelastic Wing Program) Reference: In-Flight Aeroelastic Measurement Technique Development,SPIE Optical Diagnostics for Fluids, Solids, and Combustion II, paper #5191-31, San Diego, 3-4 August 2003 Contact NASA-Langley: Gary Fleming Email: g.a.fleming@larc.nasa.gov