I was looking up at a 744 flying overhead at around (I guess) 37-40,000ft. What struck me that I didn't notice before were the contrails. Unlike what we see in FS9, the contrails on actual airliners in more intense right behind the engines and fizzles out at the end. In FS9 it's exactly the opposite. The contrails are more intense at the tail (the farthest away from the engines). I never noticed this before... I hope this get's addressed in FSX. I would also venture to say maybe it all depends on the conditions above because I've seen contrails expand quite a bit long after the aircraft has left the area. Then you have contrails that maintain their narrow characteristics until they eventually fizzle out. The common factor that needs to be addressed in FSX is you never have a condition where there's little or no vapor right behind the aircraft. Usually that's the most intense area for the vapor and from there it depends on the atmosphere how the tail expands before dissipating...

Great call on this Chris... :-beerchug I have no clue as to how MS would address this because as you noted there's different effects for contrails based on atmosphere conditions. Nevertheless I hadn't noticed a problem with this in FS9 until now... :-)