Transformers 2007 Movie - F22 Would Never Fly Below Buildings
When The rangers reach the city and they spot the first F-22 which is really Starscream they make a point of saying that F-22 pilots would never fly below building that ain't friendly thats alien. When the real Air Force finally reachs the city and attacks Megatron the whole squadron is flying below the buildings.
I would think that the military would make exceptions when giant, superior, alien robots with weapons attack a city. Flying below buildings would seem like a good alternative to letting the Decepticons attack the city.