Captain Edward J. Ruppelt:
The night before a Mid Continent Airlines DC-3 was taxiing out to take off from the airport at Sioux City, Iowa, when the airport control tower operators noticed a bright bluish white light in the west. The tower operators, thinking that it was another airplane, called the pilot of the DC-3 and told him to be careful since there was another airplane approaching the field. As the DC-3 lined up to take off, both the pilots of the airliner and the tower operators saw the light moving in, but since it was still some distance away the DC-3 was given permission to take off. As it rolled down the runway getting up speed, both the pilot and the copilot were busy, so they didn't see the light approaching. But the tower operators did, and as soon as the DC-3 was airborne, they called and told the pilot to be careful. The copilot said that he saw the light and was watching it. Just then the tower got a call from another airplane that was requesting landing instructions and the operators looked away from the light. 

In the DC-3 the pilot and copilot had also looked away from the light for a few seconds. When they looked back, the bluish white light had apparently closed in because it was much brighter and it was dead ahead. In a split second it closed in and flashed by their right wing, so close that both pilots thought that they would collide with it. When it passed the DC-3, the pilots saw more than a light - they saw a huge object that looked like the "fuselage of a B-29." 

When the copilot had recovered he looked out his side window to see if he could see the UFO and there it was, flying formation with them. He yelled at the pilot, who leaned over and looked just in time to see the UFO disappear. 

The second look confirmed the Mid Continent crew's first impression the object looked like a B-29 without wings. They saw nothing more, only a big "shadowy shape" and the blulsh-white light - no windows, no exhaust. 

The tower had missed the incident because they were landing the other airplane and the pilot and the copilot didn't have time to call them and tell them about what was going on. All the tower operators could say was that seconds after the UFO had disappeared the light that they had seen was gone. 

When the airliner landed in Omaha, the crew filed a report that was forwarded to the Air Force. But this wasn't the only report that was filed; a full colonel from military intelligence had been a passenger on the DC-3. He'd seen the UFO too, and he was mighty impressed. 

I thought that this was an interesting report and I wondered what the official reaction would be. The official reaction was a great big, deep belly laugh. 

This puzzled me because I'd read that the Air Force was seriously investigating all UFO reports. 

I continued to eavesdrop on the discussions about the report all day since the UFO expert was about to "investigate" the incident. He sent out a wire to Flight Service and found that there was a B-36 somewhere in the area of Sioux City at the time of the sighting, and from what I could gather he was trying to blame the sighting on the B-36. When Washington called to get the results of the analysis of the sighting, they must have gotten the B-36 treatment because the case was closed. 

I'd only been at ATIC two days and I certainly didn't class myself as an intelligence expert, but it didn't take an expert to see that a B-36, even one piloted by an experienced idiot, could not do what the UFO had done - buzz a DC-3 that was in an airport traffic pattern. 

Source: The Report on Unidentified Flying Objects, page 84