Watching airplanes fly overhead, I have always thought to myself, "That's what I want to do."
This sounds a bit off. You wanted to fly overhead like an airplane? As a passenger in an airplane? As a crew member? A pilot? I can guess where you're going with this, but you should revise it anyway.
The goal of attaining an Aerospace Engineering degree has made me work hard throughout high school.
Never mind. I thought you were going to say you wanted to be a pilot, not an engineer. Your first sentence is therefore much worse than I originally thought, as it is actually misleading.
An Aerospace Engineering degree will assist me in being successful after college due to the large amount of enthusiasm I have for the subject.
Wouldn't it be just as useful if you weren't enthusiastic?
fter looking at many colleges and meeting with the University of Illinois Aerospace Engineering Department head, Professor Dutton, I feel that the University of Illinois would best suit me as a student to be successful in studying Aerospace Engineering and helping me achieve my professional goal.
This part is nice, because you reference a specific professor. And why, exactly, do you feel that way?
My professional goal is to become a United States Air Force pilot.
Oh, wait, you do want to become a pilot. Wouldn't an engineering degree be better if you wanted to become a plane designer?
Hmmm . . . maybe I just don't know enough about the ordinary career path for a pilot, but your decision seems odd to me after reading your essay.