Developing of tornado missile design gust load spectrum for bomber-mounted air-to-ground missiles

The gust load is the primary source of fatigue damage for air-to-ground missiles carried on the fuselage of bomber-type aircraft. To assess the lives of these missiles, it is necessary to develop the gust load spectrum for air-to-ground missile launches. This study provided an explanation of the characteristics of air-to-ground missiles and analyzed the gust load environment during their service. Based on the typical mission profiles of air-to-ground missiles, discrete gust speed exceedance curves were collected from measured data. A discrete gust model was applied to calculate gust load responses, resulting in a family of gust vertical acceleration cumulative exceedance curves applicable to a wide range of altitudes for air-to-ground missile spectrum development. A representative curve for typical usage situations was obtained by statistical analysis. A flight-by-flight spectrum for air-to-ground missile launch was created from a 5-by-5 spectrum of gust vertical acceleration based on mission segments. This spectrum presented herein serves as an indicative reflection of the anticipated gust environment for air-to-ground missiles. This study addresses the challenge of formulating the gust spectrum for air-to-ground missiles during the design phase, particularly in situations where measured loads are lacking.