Originally Posted by KenV
And about those TriStars: fuel capacity of the -200 is 180Klb and OEW is 248Klb. So fully fueled an empty TriStar weighs 428Klb. MTOGW is 466Klb. So fully fueled a TriStar can still carry a 38Klb payload. If RAF TriStars can reach MTOGW with fuel alone, then they also must have additional tanks installed.
They did (and the RAF ones were -500s) - if my memory is correct the additional tanks added approx 100Klb of fuel capacity