New method for calculating aircraft single-hit vulnerability considering threat ricochet

When computing the vulnerability of an aircraft to a single threat hit, the assumptions are usually made that the threat travels along a straight trajectory and the ricochet is ignored. In the actual encounter environment, when the threat velocity satisfies a certain condition, the ricochet will happen and the straight trajectory assumption will not be true. We propose a new method for aircraft single-hit vulnerability assessment considering the effects of threat ricochet. In this method, the JTCG/ME (Joint Technical Coordinating Group/Munitions Effectiveness) penetration equations are used to calculate the actual path and the change of state-of-motion of threat. Using 'shotline scanning method', the vulnerable area corresponding to each shotline is calculated and thus the vulnerable area and kill probability of the aircraft are obtained. A calculation example is given in Table 2. In the example, comparisons are made for the vulnerability of 26 standard threat aspects using the proposed method and the commonly used method. Results show that: (1) since the ricochet is considered, the proposed method provides a more realistic and effective aircraft vulnerability assessment; (2) when the ricochet is considered, the computed aircraft vulnerability will usually increase compared with the case where the ricochet is not considered, and the increment is relative and sensitive to the threat aspect; (3) in the aircraft combat survivability or vulnerability assessment, the threat ricochet should not be ignored.