"manoeuvring sets up gyroscopic and bending loads on the rotating bits."
Which may explain why the Pegasus was the first (AFAIK) engine to run with contra-rotating shafts (or spools as gas turbine people seem to call them).
This was one of the avant garde features of the SABRE design but now the Trent 900 uses it well it's gone mainstream, although probably not due to the A380's need to do snap turns in a dogfight :) .
Biting the hand that feeds IT
