Hmm interesting thread this one.
95" diameter at 3900rpm. Unless I have done my sums wrong, that equates to a blade tip speed of somewhere over 1100mph, which to me as the guy sitting back in the cabin with his G&T is quite staggering (even without the G&T). I know at normal T&P's, that would be way over the speed of sound, however of course, a jet engine is far from a place of normal T&P. Assuming my calculation is correct (and I am no way suggesting the sonic shock wave contributes to the sound heard outside), how is the transition to supersonic blade speed which presumably takes only a few seconds handled within the engine ? It must put unbelievable stresses on the components.
If I am talking cr*p or asking cr*p questions, please dont shoot me down in too many flames. Just take it as an example of a little knowledge being a dangerous thing.