I have located a very good reference document published by Boeing that provides some excellent performance graphs
http://www.boeing.com/commercial/air...s/777rsec3.pdf
If one reviews these, then whatever the prevailing conditions at NCL one is looking at only up to 85% of MTW, & possibly less in adverse conditions off 25. Now that may be enough for 100% pax depending on sector length required.
Above is an extract of an earlier post I made that says it all as to 777performance criteria. Form your own conclusions !
