Envelope protection for contaminant-induced adverse aerodynamics on a wing using flap hinge moment measurements

A hinge moment based stall prediction method originally designed using 2D airfoil data is extended to a 3D wing. Experimental hinge moment measurements were obtained for a NACA 3415 semispan wing model in a clean configuration and with various simulated leading-edge contaminants. The effects of the simulated contamination configurations on the 3D wing and approximate 2D sectional performance are presented. These unsteady hinge moment data were processed through three detector functions to provide envelope protection for the clean and contaminated wing. The envelope protection advisories predicted by the detector functions are shown to be effective in predicting the angle-ofattack boundary of the normal flight envelope across various flap setting configurations and contamination configurations for the wing. Moreover, the use of the envelope protection system on data obtained during an unsteady pitch maneuver suggests that the envelope protection system may also function effectively in a dynamic environment. These results establish the viability of using this method on a flight vehicle.