"The plane was towed out of the hangar."
"The plane was towed out the hangar."
I found myself writing that second sentence because it's shorter and seems to flow better. Does it violate any grammar rules? I can't explain my suspicions that well. It trips some grammar alarm in me. The removal of a preposition is something to be wary of I guess.
BTW, it's the narrator saying that in exposition, so I can't pass it off as colloquial speech.
And curiously, how would you diagram both sentences? The first one has two prepositions in a row.