If you are asking about contrails it is dependent on the temperatures aloft. At colder temperatures the water vapor in the exhaust condenses and causes the contrails you see.
The blue angels and other aerobatic-performance aircraft inject a special oil "smoke oil" into their exhaust in order to leave the smoke trail you see at airshows.
But the "smoke trail" you see behind civilian and commercial aircraft isn't smoke at all, it is water vapor formed as described above.
i dont know leave me alone
i dont know leave me alone
they leave a silver trail so they know the way home jks its so they can "walk". because snails dont have to legs they produce a slime so they can slide across it, leaving a silver trail.
i dont give a f@#% dont smoke and i dont give a #$%^.
i dont know i was asking how many dont smoke i dont know the answer if it was my question
i really dont no
I dont no
dont smoke
no he dont smoke..
i dont know it gears the plane
no Garth dont smoke
they dont