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" The department has not conducted UAV flights anywhere along the border since its only operational Predator B crashed in April outside of Nogales , Ariz. Security , has tested UAVs along the Mexican border , and is considering using these surveillance planes permanently . For years , officials in the Army and Navy , which manage their own UAV programs , complained that the Air Force , whose leadership is dominated by pilots , has n't pursued UAV technologies aggressively enough . " The U.S. Department of Defense has used UAVs in military operations since the 1950s to provide reconnaissance , surveillance and intelligence of enemy forces without risking the lives of an aircrew . The Earth Science Enterprise now has added UAVs to the stable of platforms available for airborne science and applications .