My father passed away some years ago. However, he shared with me a report of a UFO sighting he had in the mountain community NW of Colorado Springs, CO. It was about 1953 when in his early 20's. He was at a friends house, his college teacher, and they talked all night about studies, not realizing the late hour. He left just before sunrise as the sky was just becoming light. When they walked out the front door together they were startled and dumbfounded by a huge UFO hovering about 40' directly above the house. He could only tell me that the craft was big beyond description. It was so big and so close that it blocked out the immediate view of the sky. Like a giant blimp right on top of you. He could see every little detail of the under belly of the craft. Not a single sound could be heard. They looked at it for several seconds and he said it then just instantly disappeared before their eyes.
He could not give explanation how this huge UFO disappeared but said it was the most unnerving experience ever he had.
He later speculated to me that the UFO either cloaked itself or maybe shifted into another dimension as he did not see it move before it disappeared.