“Project Sign and the Estimate of the Situation”
by Michael D. Swords
(Journal of UFO Studies,
New Series, Vol. 7, pp. 27-64, 2000)
(NICAP.org)
Project Sign, the first UFO investigation project of the U.S. Air Force, formally began its work on 22 January 1948. It operated formally for about one year, the calendar year of 1948, according to Dr. Michael D. Swords:
http://www.nicap.org/papers/swords_Sign_EOTS.htm
Organisational Chart, U.S. Air Force Intelligence, ca. 1948
(nicap.org image)