Missile warning systems operating in the ultraviolet part of the spectrum have become a common part of the suite of self-defence systems of modern aircraft. These systems have a low false alarm rate and a detection range of several kilometers against man-portable surface-to-air missiles. The performance of the missile warning systems depends on several factors, including weather and threat type. This paper uses a generaic missile warning sensor and a recently developed model to predict missile plume UV radiance, to demonstrate the variability in detection range for a number of typical threats, weather types, aircraft speeds and warning system lay-outs. The variation in sensor performance present in the results shows that an assessment of the level of platform self-protection prior to each mission should be performed.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.