The response to atmospheric gusts of a lightly damped airplane model flying at a Mach number of 0.7 at sea level has been studied analyt-ically with elevator fixed and with varying amounts of viscous restraint of a mass-overbalanced elevator. Although in a sharp-edge gust the vis-cously restrained mass-overbalanced elevator has negligible effect on the motion of the airplane center of gravity until the first peak in the normal-acceleration response of the model has been reached, the effective damping ratio of the subsequent motion can be more than trebled by a suit-able choice of viscous restraint with some reduction in frequency of oscillation. In continuous gusts, calculations indicate that for the model considered there results a 20-percent reduction in root-mean-square normal acceleration at the center of gravity over a broad range of eleva-tor viscous restraint.
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