I don't buy into a universal key to dreams and symbols. The same image often conveys completely different emotions for different people, depending on tons of factors. There's also a lot more to dreams than only symbols - the same image may be trying to convey different things depending on the place it occupies in your dream.
More often than not, we are tempted to read our dreams in the most flattering ways, to find in them something which speaks to our pride, whereas more often than not, our dreams are there to bring into light the exact opposite side of us, the one we don't want to acknowledge. Too easy an interpretation is likely to be questionable.
My own recurring dreams involve planes and flying objects, hanging menacingly heavy above my head, or coming to crash on me. They're often combined w/ other means of transport - a plane that crashes on my boat, a plane that crashes on a train I'm in, a plane that crashes on a plane I'm in...
Did I mention hate planes?
I even wrote a song called "planes keep on crashing on my head" at one point, which, incidentally, helped me get rid of the dreams for years.