For the original poster, I'm still not clear what graphs you are referring to? I now have access to my RFMs and the cruise torque and fuel flow graphs in the Part 2 Section 3 (supplemental performance) clearly go to 16,000 ft so I do know what graph you want for 15,000 ft? You can, indeed, interpolate the data from the 14,000 and 16,000 ft graphs if you really need 15,000 ft data from this section, but I get the impression you are talking about something else?