I haven't made a comment on this yet, but I've got a few minutes now so I will.
My personal opinion? That...er "appendage" on the bottom makes the ship look UGLY. I don't care what it may look like. To be honest my original thoughts on it were. "What the hell is that thing doing on the ship. o_O ...and the fact that it looks like 'that' doesn't help. XP" And although that is a minor factor, even if it didn't look like 'that', it'd still look ugly to me.
That part just looks like a huge, useless something or other. It's practically the same size of the dang fighter. If you insist on keeping it though, I'd suggest to reduce the size, give it different details, and give it some kind of purpose. Just looks really out of place and doesn't serve any kind of purpose. Also it'd make the fighter a huge flying target.
Though that's just my opinion, and it's your fighter. I just wanted to give some non-"OMG ITZ A PENIS" critisism.