411A, OK, I pushed it a bit... But it has been a while and I do not have performance figures for the airplane on two engines, indeed I am not aware of any. I am basing my opinion on the sim, which of course might not be accurate since there is no regulatory requirement to even prove a rate of climb etc on two. However if the sim is not too far off, a light 747 on two engines is more than capable of a gradient of climb close to a twin, including a go-around, provided the drag and airspeed are managed properly, and there is no particular handling problem, even when the two failed are on the same side. There is a difference of around 130,000 Kg between max takeoff weight and landing weight after all. Of course I did not claim the twin was also at a light weight!