Somebody wiser than me has covered the Landing Distance some time ago:
http://www.pprune.org/tech-log/21117...ml#post2393979
Generally, the landing distance even at Max Takeoff Weight will be less than the the required takeoff distance on the same runway....assuming everything is working.
Qantas had multiple failures of high lift and retardation devices, giving a much higher than normal approach speed (at their reduced weight) and requiring all of the 4000m runway length. I
guess an immediate landing at a few tonnes below their actual takeoff weight
may have required more than 4000m.
From 747-400 FCTM
Overweight landings may be safely accomplished by using normal landing procedures and techniques.There are no adverse handling characteristics associated with overweight landings
Landing distance is normally less than take-off distance for flaps 25 or 30 landings at all gross weights.
However, wet or slippery runway field length requirements should be verified from the landing distance charts in the FCOM 2
Brake energy limits will not be exceeded for flaps 25 or 30 landings at all gross weights.