Lomapaseo
Going back to my days as a R-R gap year student I know that we had to look at the capability of the engines to windmill and not shake themselves apart following a Fan Blade Off event and also to windmill safely in-flight in an engine off condition I.e. that windmilling in-flight iunder emergency conditions would not cause dangerous situations (as I was involved in the load calculations) but I am unsure whether we had to show on-ground windmilling capability.
Obviously the first 2 situations which we definately had to show were emergency situations in which you could quite happily wear your bearings out as long as it remained intact and didnt eject any materials.
That said any wet seal will retain some oil inside it which would provide limited lubrication and windmilling will allow the bearings to rotate preventing 'egging' where a stationary shaft would cause deformation of the seal due to its weight resting on the same point of the bearing for long periods of time.
Last edited by Burnie5204; 10th Aug 2013 at 14:36.