Project Blue Book Special Report No. 14: Analysis of Reports of Unidentified Aerial Objects

Special Report No. 14 was issued by the U.S. Air Force's Air Technical Intelligence Center on 5 May 1955. It is a statistical study of about 4,000 reports of unidentified aerial objects from June 1947 to December 1952. The reports were reduced to IBM punched cards and analyzed with methods including chi square tests. The report concludes that the reports it examined are very unlikely to represent technology beyond present scientific knowledge, and it notes that no case produced valid physical evidence.

f
Total Less Aircraft
40
i
30
Per Cent
20
i
10
Aircraft
Per Cent
c
January
February
March
April
May
June
July
August
September
October
November
December
) 10 20 30 4
i i i i
:
i
i
m
FIGURE 25 COMPARISON OF MONTHLY DISTRIBUTION OF OBJECT SIGHTINGS EVALUATED AS
AIRCRAFT VERSUS TOTAL OBJECT SIGHTINGS LESS AIRCRAFT
A-7303