Decade
UAP history in the 1940s: 8 entries in date order, each with public sources. By track: Military (3), Government (3), Sightings (2).
In summer 1946 Swedes reported hundreds of rocket-like objects; on July 19 witnesses saw one dive into Lake Kolmjarv, but an army search of the lakebed found nothing. A Defence Staff committee attributed many reports to meteors, suspected Soviet tests for the rest, and never found proof.
Private pilot Kenneth Arnold reported nine fast objects flying in formation near Mount Rainier. Press coverage of his account set off the first U.S. wave of flying saucer reports, and the Air Force later carried the case as unexplained.
Roswell Army Air Field announced it had recovered a "flying disc" from a nearby ranch, and the Army said the next day it was a weather balloon. A 1994 Air Force report concluded the debris most likely came from Project Mogul, a then-secret balloon program.
Lt. Gen. Nathan Twining, head of Air Materiel Command at Wright Field, wrote to Army Air Forces headquarters that the disc reports described something real, not imagined, and urged a classified, prioritized study. That study began months later as Project Sign.
The Air Force's first formal study of flying-saucer reports, run by Air Materiel Command at Wright Field. It ran until early 1949, when Project Grudge replaced it.
Kentucky Air National Guard Capt. Thomas Mantell died when his F-51 crashed while climbing after an object reported by the Godman Field tower near Fort Knox. Investigators concluded he likely lost consciousness from lack of oxygen; a Navy Skyhook balloon is widely cited as the object.
Eastern Air Lines pilots Clarence Chiles and John Whitted reported a glowing, wingless, cigar-shaped object with rows of lit windows passing their DC-3 near Montgomery at about 2:45 a.m. Ruppelt said it prompted the Air Force's 1948 'Estimate of the Situation'; the case was later relabeled a meteor.
The Air Force renamed Project Sign as Project Grudge, a scaled-down successor that treated most reports as misidentifications. Its 1949 report concluded sightings came from misread natural objects, hoaxes or psychological causes.
