 The massive shoot of the "target building insert" sequence was  intended to be among the first sequences shot in principal  photography, due to its complex nature. However, negotiations to  borrow four Black Hawk helicopters from the United States military  were so arduous that an agreement was not reached until a month  after shooting had commenced. Director Ridley Scott had prepared a  rental of four Hueys from Germany that were ready to be painted  black and work as substitutes in the event an agreement with the US  Department of Defense could not be reached. Fortunately, the US  Government was eventually satisfied that the film would portray the  incident in a positive light, and shipped the helicopters to the  location in two C