Annoying kid in my cl who is an EXTREME plane fan. Never leaves me alone. What should I do?

Ignore him. If he sees that he is having no effect on you and that you don't care about his airplanes, he'll stop eventually. Also, I think if you are with you friends and they start to make fun of him just be like, "Hey guys, it's really not that funny. He's not that bad. Just lay off." Your friends will most likely feel embarred for even making fun of him in the first place if you confront them about it.