For my ai aircraft I have 744fs of the three engine types PW,GE,RR.I also downloaded the user aircraft realisic sound files for the three variations. The problem is that how do assign the three engine sounds to them? As far as I know, there can be only one soundai folder in each aircraft folder and extensions .RR, .PW, etc don.t work.The sounds don't exatctly sound the same for AI aircraft engines as they do when I fly them myself, also in spotview the roar of the engines when viewpoint is at the rear and jet whine when viewing from front of the plane is not distinguishable,can this be fixed?

I haven't got that far - but I'd expect you are going to have to have separate foldersAIA_B744F_PWAIA_B744F_GEAIA_B744F_RRto make a separate ai sound set work for each.