Free-oscillation damping measurements at hypersonic and transonic Mach numbers are presented for the lower pitch flap of the M2-F2 reentry vehicle. For the flow and model conditions tested, the damping measurements indicate the absence of hypersty for flap rotation frequencies of 47.3en1 Hz, 153 Hz, and 360 Hz, the presence of transonic buzz for 47.3en1 Hz flap, and the absence of transonic buzz for a 115en1 Hz flap. There are not enough flap damping data for an error estimate based on repeatability, but a partial damping calibration is presented in which an analog computer simulation of random flap response for a known flap damping is fed into the autocorrelation computer and filter combination used for most of the damping measurements. (Author)
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