KJFK: Huge delays (>3 hours)...abbreviations

[Guest wesl]

You can only have two airplanes on the runway landing if both weigh less than 12,500 lbs. Then the first aircraft must be 3000 or 4500 ft down the runway depending on the weight category involved, cat1 or cat2.Wes

[Guest JamieG]

ok that makes sense, thank you very much for the help!