Commercial airline pilots and flight crew spend more time in the sky than anyone. It's no surprise, then, that many UFO sighting reports have been generated by pilots and airline personnel. UFOs have chased commercial flights and even collided with them. One UFO hovered in plain sight above Chicago's O'Hare Airport and was seen by dozens of witnesses. However, despite thousands of sightings, pilots are still discouraged from publicizing their experiences, and the few that do have faced professional ridicule and loss of their jobs. Hangar 1 files uncover many UFO incidents, and suggest that the next time you fly, keep your window shade open. You never know what you might see up in the skies.