 It continued to suffer from numerous development problems, not the least of which was that ongoing issues with the active radar seeker (for which the designers GEC were pilloried on numerous grounds) caused a size and weight spiral.This in turn detracted grossly from the flight performance, which was dismal for such a large missile.Poor seeker performance in turn demanded a large warhead, which exacerbated the weight problems, while design limitations inherent in the light alloy structure made it unsuitable for use on highly supersonic interceptors.