Capt. Willis T. Sperry with about 10,000 flying hours, copilot Bill Gates, flight engineer Robert Arnholt, a stewardess and two to three or eight passengers on a DC-6 airliner were headed 230° out of Washington, D.C, en route to Nashville, at 7,500 feet at 250 mph. Gates saw a spindle-shaped 150 feet long metallic object with an intense blue light (about magnitude -6) on the tail on a head-on collision course. Sperry made an evasive 45° turn to the right. The object passed from 11 o'clock to seven o'clock position to the left at slightly higher altitude, crossing in front of upper part of full moon to the south. The submarine-like silhouette was clearly seen, about five miles away. Sperry turned left back onto his original course to get the object back in view. The object may have stayed stationary about 30 seconds at this point. Gates then noticed the object circled around to the right side. Sperry banked right again, while the object paced the airliner about 20-30 seconds before climbing to the east at a 30° angle at "fantastic" speed and disappearing.

One blue-metallic ball was observed by 6-12 witnesses in-flight for two to three minutes (Gates, Bill; Arnholt, Robert; Sperry, Willis T).

Ruppelt's account:

On the night of May 29, 1950, the crew of an American Airlines DC-6 had just taken off from Washington National Airport, and they were about seven miles west of Mount Vernon when the copilot suddenly looked out and yelled, "Watch it--watch it." The pilot and the engineer looked out to see a bluish-white light closing in on them from dead ahead. The pilot racked the DC-6 up in a tight right turn while the UFO passed by on the left "from eleven to seven o'clock" and a little higher than the airliner. During this time the UFO passed between the full moon and DC-6 and the crew could see the dark silhouette of a "wingless B-29." Its length was about half the diameter of the full moon, and it had a blue flame shooting out the tail end.

Seconds after the UFO had passed by the DC-6, the copilot looked out and there it was again, apparently flying formation off their right wing. Then in a flash of blue flame it was gone--streaking out ahead of the airliner and making a left turn toward the coast.

The pilot of the DC-6, who made the report, had better than 15,000 hours' flying time.

Google map of this location.