Using an assumed spectral density function, the ratio of the maximum gust of t seconds averaging time, drawn from a sample duration of T seconds, to the maximum S-second gust from a Θ-second sample is derived using the theory of the effects of averaging times and finite sample lengths on estimates of population parameters. The spectral density function is defined so that only one parameter a has any effect on the ratio. This parameter may take varying values to allow for changes in stability and terrain. Suggested practical uses of the ratio include aviation landing advices for newer type aircraft particularly sensitive to gusts.