From the time Hud first spots the monster in the helicopter to the time the helicopter crashes is less than a minute, yet the time changes from night to sunrise. However, the military man that told them of the helicopter told them that the last helicopters would be in the air by 6:00 am. The time from the crash to the time when the camera restarted recording is unknown, but it is possible that the sun began rising at that point. Even their visibility in the helicopter was getting much better and looked like the early dawn.