I downloaded and installed the above sound set. The instruction steps 1 and 2 are clear. Step 3 about modifying the aircraft.cfg is not all that clear. When I changed fltsim.0 to what is in the instructions all 767-300ER vanished from the FSX Free Flight list. I had a backup copy of the cfg file and restored that so everything is ok.
I know people on this forum have installed the set. How did you do it?

Thank you
Michael Cubine