RB211 is a brill engine from maintenance and reliability point of view. Nice and easy to work on and very simple due to tripple spool design. You don't need so many bleed valves or any variable inlet guide vanes atall. Fuel efficiency and engine spool up times are much better, again due to tripple spool --I think Royces' have the patent for this design,hence Pratt plus G.E. can't use it!! Anybody know this for certain?