The Effects of Low Level Turbulence on the Structure of a Large Logistic Aircraft

Atmospheric turbulence measured at low altitudes over rough terrain in high wind conditions is shown to be more severe than the turbulence previously measured in thunderstorms. The military requirement for large bomber and logistic airplanes to operate at low level thus will result in large weight and performance penalties unless some means to reduce structural loads is employed. By use of power spectral density techniques, it is shown that loads in low level turbulence can be reduced on large airplanes with an adequate stability augmentation system. This load reduction is sufficient to insure that large aircraft operating at low level will not be unduly penalized in performance.