While destroying an X-4 Stormwing may not seem like that hardest challenge to complete, it’s certainly not easy to do it while the plane is still air-bound, especially if the enemy will be trying their very best to avoid damage.
Instead, there is actually another method that’s much easier, more efficient, and can be done without having to wait around or engaging an enemy plane.
This method, shared by Reddit user ‘sniperman599,’ involves finding an unoccupied Stormwing, inflicting damage upon it while it’s still on the ground, hopping in to start flying it, then jumping out and shooting it down to complete the challenge.
The reason this challenge works is that once the player jumps out of the flying Stormwing, the unoccupied plane will continue to slowly fly in a straight line, giving the player plenty of time to glide down to the ground and shoot at it from there.
The key here is to do enough damage to it while it’s on the ground but making sure not to accidentally do too much damage and destroying it. This makes the rest of the process simple and easy.
The method could work even better when doing it with teammates, since one can fly the damaged plane and then jump out of it so that it can be immediately shot down by the other free v bucks generator.
As for where to find these planes, here is a handy map that shows all of the known locations where the X-4 Stormwings naturally spawn in.
You will still need a weapon of some sort to complete this challenge, so landing directly next to a plane right away may not be the best idea.