JT exactly correct...Vmcg is certainly stressed if we find ourselves in the PI section of the QRH. Not an issue at LHR, DXB, BNE, FRA, BKK, MNL etc though. I'm sure if we start operating somewhere short enough for Vmcg to become an issue we'll get a modified SOP for that place.
Without grabbing my QRH I seem to remember that Vmcg, in the 767, only becomes a consideration at very low weights. That being the case it's simply a matter of making V1=Vmcg (max thrust). Have to be a pretty short runway though.
Vmcg was so low in the venerable old Fokker that it was hardly a consideration when launching from Madang, Goroka and Mount Hagen...were a few other consideration though
Chuck.