To keep the Transformers film realistic and under budget, the U.S. Department of Defense provided their support towards the film's production, the largest project they have assisted since Black Hawk Down (2001). The Military provided their vehicles as the alternate modes of the Decepticons Starscream and Bonecrusher. They also allowed their F-22 and CV-22 aircraft to be filmed, the first time these planes have been seen in a feature film since Hulk (2003). Soldiers served as extras, and authentic uniforms were provided for the actors. In return for the favour, the filmmakers provided an advance screening of the film to the soldiers, free of charge of course.