[QUOTE=Lord Bracken;10298996]Won't Mr Rolls sell you a Trent XWB -75 or -79 which fits the 75-80 rating with ease? You can even hang them on an A380, as Airbus have proven.
/QUOTE]
I believe the -75 and -79 were planned for the A350-800 -- a model that AB has dropped -- so these engines never went into mass production. Further, because these are down-rates of the -84 and -97 used on the A350-900 and A350-1000, respectively, it is likely that their performance suffers somewhat, and still may not reach the parameters that were originally promised to Emirates.