One of the “interesting” aspects of the BA flight that departed LAX and had an engine surge, declared an emergency then decided to continue to LHR on three but ended up landing in MAN having put out a mayday due to miss management of the fuel system was that during engine certification they had to show that a good engine could be windmilled for 2 (or 3?) hours without damage. Wondered what 11 hours did to a damaged engine.