Is there any possibilty to make the jets have trails? I've heard of FS Clouds or something like that, but I would prefer something that does not cost anything.

Just fly at FL300 or over, and your contrails will appear (maybe the aircraft needs to have something set in the mdl or fde for it, but I've not yet seen a jet that didn't have them, even ones I pulled over from FS2000).

Yeah, that's right, of course. But these trails only appear at your own aircraft, and disappear very fast. But I want something like in reality, just have a look at the sky - you'll see many jet trails there, and that's, what I want.

Try this one from AVSIM library. Works well.- Kenny B

I think that's it what I've been looking for. Looks quite good, thanks!

That would be nice, but there are two problems. First, from a large distance the trail will be too small and the width less than one pixel, so it wouldn't appear. But the effect could be modified to make it larger, for example by making it spread out over a much larger area as in real life. But the bigger problem is that the visibility distance of the effect is too small, so it would be absolutely impossible to see it, for example, from the ground. Scenery designers have an urgent need to be able to increase visibility distances for effects (e.g. volcanic eruptions) but as far as I know no one's found the answer. If anyone does know how to increase the visibility distance for effects, please let me know.... Best regards, Chris