Ace Killer Achievement

This is a lot easier than it sounds as you technically don't have to be flying. The video below explains it best but here's a quick guide.

1. Head to hanger within Hope County where you can buy/spawn and plane which has a machine. The Carmina, Clusterduck, The Wild Goose are the three you'll need to look at. If you don't have the money, the Carmina is unlocked by completing the 'Air Raid' mission given to you by Nick from Rye & Sons Aviation in John's Region.
2. Take the plane and move it forward and do a u-turn so that you're now facing the planes spawn position.
3. Now head back to the shop and spawn another plane.
4. Once done, head back into your original plane and simply shoot the newly spawned one until it's destroyed.
5. Simply repeat this process nine more times to unlock the achievement.