STATISTICAL DISCRETE GUST-POWER SPECTRAL DENSITY METHODS OVERLAP - HOLISTIC PROOF AND BEYOND

The statistical discrete gust (SDG)-power spectral density overlap of ($) over bar gamma = 10.4 ($) over bar A claimed by J. G, Jones, and v erified by B. Ferry III, A, S, Pototzky, and J, A. Woods, does exist. The analytical results consist of numerical substantiation of specific aircraft models. The claim is valid up to approximately +/-10% about the 10.4 factor, This article presents a mathematically rigorous proof from basic principles without specific aircraft models and very restr icted gust shapes, By invoking Chebyshev's inequality, the extension t o ($) over bar gamma(max) = 25-150 ($) over bar A for true design gust loads becomes a reality to complete the holistic proof. This article also introduces the allencompassing fractal geometry representation of turbulence that uses their respective Hausdorff (fractal) dimensions to derive all known spectral shapes. A sample case explains the obviou s impacts from these different shapes on gust toad exceedance. A two-t ier approach proposes concrete changes in FAR 25 requirements, Realist ic: assessment of SDG method's role in gust load analysis points out s ome of its shortcomings and virtues.