Hey guys.Thanks for all the replies.However, you have the wrong idea.By swarms, I mean imagine a swarm of bees, Not a flock of birds... This happens at cruise, generally when I am in 4x speed or having just slowed to 1x again.FS will show the reloading dialogue box and when the flight resumes, the time has been +/- by an hour and all of a sudden there are 200+ aircraft in one point in the sky. The begin to spread out, but you can imagine the job that my PC has to generate them all.They don't even belong in that area of the world.For example, I was over Japan. I had aircraft in the swarm that were routed JFK-LHR etc.