Originally Posted by
ThreeGreens
That's not the answer to my question.
Yes it is. The 1.67 is a multiplication factor to get the 60% distance. If your AFM landing distance is 2500' then 2500 x 1.67 = 4,125 your minimum runway length. The AFM number is still your actual stopping distance, so if you stop in 2500 ft, you're only using 60% of a 4,125 ft runway. That's the whole idea of using the factor for planning.