As these fellas have said, more info is essential. What's your Dad's name, his rank(s), or his years of service? Any bit of information you can provide may be helpful.
Documents or photos will usually yield the best clues. If you have any of either, post them here if you're able to do so.
If you don't have anything along those lines you could make a post on the forum at The United States Army Air Forces in W.W.II and ask how to obtain your Dad's service records. The folks over there are very helpful with that kind of thing.