A British Airways plane departs London's Heathrow Airport in 2010. Earlier this month, a British Airways plane was hit by an unidentified object but landed safely at Heathrow.
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A U.S. Air Force MQ-1B Predator unmanned aerial vehicle, carrying a Hellfire missile, lands at a secret air base after flying a mission in the Persian Gulf region on Jan. 7.
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A helicopter flies near the Lake Fire in California's San Bernardino National Forest on June 19. Firefighters mobilized to combat the wildfire from the air, but they had to be grounded to avoid drones in the area.