..the changes on the Trident which destroyed it's sales potential...when did it go..1985 whilst the VC10 bowed out last year.
I think the emasculation of the dH121 at BEA's behest into the ludicrously undersized Trident is well documented. In being so truncated it used the Spey and RR ditched the proposed Medway the 121 would have used. When the Trident did eventually mature into a reasonably-sized aeroplane (T3) it was still stuck with the too-small Spey and had to have that boost engine cobbled-in for 'hot and high' T/O.
Oh, and of course by then the 727, T3 sized from the start, had taken the world market!