Extraction of Longitudinal Aerodynamic Coefficients from Forward-flight Conditions of a Tilt Wing V/STOL Airplane

Download or read book Extraction of Longitudinal Aerodynamic Coefficients from Forward-flight Conditions of a Tilt Wing V/STOL Airplane written by James L. Williams and published by . This book was released on 1972 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: A parameter-estimation algorithm was used to extract the longitudinal aerodynamic derivatives from flight data for the XC-142A airplane in a cruise condition. The flight data were the response to a tail-plane doublet input. Results of this study showed that a set of derivatives were determined which yielded a calculated aircraft response in close agreement with the measured response. This calculated response was in much closer agreement with the flight data than the response obtained by using derivatives which were calculated from empirical methods. There were large differences between some of the important derivatives extracted from flight data and those calculated from empirical methods. The reasons for these differences were not identified.