Dive BOMber achievement???

Does anyoen know what exactly you need to do to get this achievement, I got some Jetpack beatdowns but I didnt get the achievement, so I’m wondering if you need a certain altitude or something like that. Thanks

You need to kill with a beat down (a melee from the back, NOT an assasination) when he’s jet-packing, meaning if you kill him whith a beat down when he’s not holding the armor ability button, you won’t get the achievement (I don’t have the game right now, but I think it’s like that)