Environmental Conditions to Be Considered in the Structural Design of Aircraft Required to Operate at Low Levels

摘要

One of the greatest problems facing structural engineers at the present time is a proper definition of the turbulenceenvironment at low level. The power spectral density approach is considered to be the most reasonable to use in defining this environment. Presently published data, while in power spectral form, do not appear to be adequate. Because a critical need for low-level design criteria exists, low-level power spectral exceedance curves have been derived from a B-66 low-level gust study, an F-106 low-level high-intensity gust program, and B-52 fleet service experience. These data indicate that low-level lateral turbulence is from 15 to 30 percent more severe than vertical turbulence. Much additional effort is required in the area of low-level turbulence before structural engineers can have complete confidence in their low-level turbulence design criteria. (Author)