Flight-test estimation of aircraft aerodynamic characteristics-Russian experience

The experience gathered at the Gromov Flight Research Institute, Russia, in the area of estimation of aerodynamic characteristics of aircraft from flight tests was discussed. Estimation of aerodynamic characteristics from flight tests were used at the Gromov Flight Research Institute, Russia, to held make decisions about expanding flight conditions with regard to the angle of attack. Estimation from flight-test data was used in those cases where the flight conditions were difficult to simulate in a wind-tunnel. Estimation method was also applied to analyze the spin flight data. The results were used to revise the restrictions established for the aircraft or to calculate various corrections during flight tests.