Abstract: In this paper, the transmission shaft of the all-moving horizontal tail for a fighter plane is considered as a structural system, and its failure probability is analysed. The Ditlevesen Bound is used to obtain the strength reliability, and linear approximation at the designing point is used to obtain the torsion rigidity reliabib'ty.Finally, the Monte-Carlo method is used to get the reliability of the most serious failure mode for the shaft.

Key words: elementary failure pr}bability, structural system reliability