This Datapack not mod, adds contrails to minecraft eyltra's. If you dont know what a contrail is its those things on the corner of the wings on a plane like this
But in minecraft for elytras.. the one in minecraft looks like this
It looks much cooler than what it looks on the image.. my very old laptop keeps lagging when i load two minecrafts.. So maybe thats why the trail looks like that. I think.
But yes the trails will dissapear when you go too slow.. and they reappear when you go fast. The density of the contrail is according to how fast your going.
Installation
Download the file and then go to your world folder which will be inside of "saves" which is inside of the miencraft folder.
Then put this zip file inside of the world file.
Then the contrails will appear after you type the command /reload or just re log into the game
