Where are people getting the idea that it even has anything to do with the attack helicopter meme? Because both things reference flying military hardware? Because as far as I can see that's literally the only "connection".

The "aerosexual" thing is because people on NCD constantly post extremely horny art of anthropomorphic fighter planes. This has nothing to do with identifying as anything. They don't want to be fighter planes, they want to fuck fighter planes, because if you're not a weirdo who's horny as hell for military hardware then what are you even doing on NCD? And the joke is, to be clear, entirely self deprecating. It's "haha, we're a really weird and fucked up community aren't we guys?"