Project Blue Book Case File
Delta, ColoradoApril 1949
Summary
In April 1949, a former U.S. Air Force pilot living near Merced, California reported experiencing a striking encounter late one night. According to his witness statement, he was stepping outside around 10:20 p.m. on April 4 when he heard an intense clicking noise coming from the sky. After searching briefly, he spotted a solid object blotting out stars and moving slowly west or northwest. He estimated it was four to five feet in diameter at an altitude well below 1,000 feet. The object reflected ground lights, appearing to be dull-surfaced light-colored metal. As it passed, it made a 50-degree left turn and the clicking sound grew louder. The sound eventually disappeared when the object was directly overhead. The pilot's dog was present and also reacted to the noise.
The witness was a former military pilot with roughly 2,200 hours of flying time who stated he had not heard news reports or broadcasts prompting him to file this report. The Air Force took the case seriously enough to have officers from Lowry Air Force Base in Colorado investigate.
However, the case took an unexpected turn. About six weeks before the April sighting report was filed, a rancher near Delta, Colorado had found three broken pieces of aluminum in the terrain. When the pieces were examined by Air Force intelligence officers and compared against historical records, they were identified as parts of a Japanese incendiary balloon that had been used during World War II. Specifically, the object was described as a wheel-shaped device made of cast aluminum with 72 holes around the periphery designed to hold explosive plugs. This was a ballast ring used on Japanese fire balloons launched across the Pacific during the war.
The Air Force's conclusion was that the unidentified object initially reported had subsequently been identified as parts from a Japanese balloon. No further investigation was deemed necessary. The full case file is reproduced below as held by the National Archives across 32 pages.
Reported location
Delta, Colorado
Date of incident
April 1949
State / country
CO / US
Page count
32 scanned pages
USAF evaluation
unknown
Microfilm
T1206, Roll 4