Andrews AFB, Md., November 1948 - Incident Number: 207November 1948

On November 18, 1948, at 2200 hours (10 p.m.), a pilot of a T-6 aircraft reported sighting an unusual object over Andrews Air Force Base near Washington, D.C. The object appeared as an oblong ball with a single light, no wings, and no visible exhaust. It had a dull gray glow and was smaller than the T-6 aircraft. The pilot made several attempts to approach and identify the object but it repeatedly evaded him, climbing above the aircraft and performing tight turns inside the T-6's capability. After approximately ten minutes of pursuit, the object disappeared as the plane reached 7,500 feet. The object's speed varied between 80 and 600 miles per hour.

The Air Force's Materiel Command opinion concluded the object was a synoptic balloon (a weather balloon used to measure atmospheric conditions). An official noted that Dr. Fitts' research had shown how difficult it is for airborne observers to separate target motion from their own motion, especially at night. The investigator stated he had conducted controlled experiments attacking ordinary balloons with a T-6 in daylight and found he could duplicate all the described maneuvers in appearance using this method.

However, the Air Weather Service examined this incident alongside similar cases and specifically noted in writing that this case was "definitely not a weather balloon," contradicting the Materiel Command assessment. The file contains detailed witness statements and extensive weather data, but the contradiction between the two official evaluations remains unresolved in the available documentation. The full case file is reproduced below as held by the National Archives across 29 pages.