Not sure about runway required; however AA
's Takeoff Planning System (at least the version available to pilots) converts everything to Gross Weights since that is the only real variable we can control. AA
flight 420/20July FAT
had a 155,200 lbs weight limit due to environmental conditions at FAT
[primarily due to runway length/terrain & temp.]. Load Control placed max 140 pax limit and max 3,400lbs cargo limit upon that flight.