I lost a friend many years ago in a 'G' model of the Mu2. The radar trace had it climbing normally out of Sydney until it reached 17,000ft and then not one track mile to the point of loss of radar return. To go straight down like that is unusual and ice seems to be one theory. I have never heard the reason or even if they found one. I know nothing about the aeroplane, having never flown one, but when I see one I always wonder if the 'orrible little thing has a dark secret somewhere. 'Tojo's Revenge' is what they call them in Aus.