Oh, OK, thx guys

There you go, getting advice from the guy who is basically at the top of the game! I'm gonna add one more small thing: do give your planes custom colour schemes. Using the default one kinda implies a lack of effort, even if you really did work hard on it

You gotta remember a couple of things: firstly, most people are able to make a plane that flies well, so another person's plane that just flies well doesn't really offer anything to them. You need some sort of novelty or interesting feature to get the attention of other people. The other thing is that almost nothing on this site will get many upvotes, because it takes quite a lot of things for that to happen. The plane needs to catch somebody's interest amongst all the other good planes out there, interest them enough to download it, and then perform well enough for them to come back and upvote it after they tested it. It's a bit more involved than upvoting a cat picture on reddit or liking a status on Facebook. Now, don't take this to mean "give up, nobody cares", because that is absolutely not what I mean - just remember that it's okay to not be super successful, and every upvote you do get is actually a pretty big deal.

If you want feedback, try entering challenges (and putting a good effort in to them, naturally). Most good challenge hosts will try every entry that doesn't get immediately disqualified for something, and people will see it as a successor to the challenge.