Abstract
The aim of this paper is to propose fighter aircraft's mission severity model which can be used as one of key factors for designing a structure and determining design life of KF-X. The mission severity is a quantitative data of flight loads and expressed by Nz(Vertical Load Factor) exceedances or occurrences. The severities of the flight loads depended on the circumstances of the countries which operate fighter aircraft. In this paper we have studied on Nz occurrences/exceedances of ROKAF fighter aircraft to generate mission severity model for the KF-X. The analyses of flight data were accomplished by using the Matlab.