An early Air Force project investigating UFOs.

Declassified on July 23, 1997, Project Grudge was originally released in August of 1949 as a SECRET Technical Report (NO 102-AC 49/15-100) by the headquarters of the Air Materiel Command, Wright Patterson AFB, Dayton Ohio. Approved by Lt. Col. Hemstreet and Col. Watson, it is 406 pages long and covers a large number of UFO sightings along with investigation analysis, conclusions, and supplementary reports.

Forerunner of Project Blue Book

Project Grudge was one of three acknowledged U.S. Air Force projects dealing with UFO investigations — the other two being Sign and Blue Book. Between 1948 (the year that saw the creation of Project Sign) and 1969 (the year in which Project Blue Book was officially terminated), 12,618 UFO reports were investigated by personnel assigned to these three projects. According to the Air Force, out of this total only 701 UFO reports remained unexplained; and that with respect to the remainder, “…there was no indication of a technology beyond our own scientific knowledge…” The Air Force further asserted (and continues to assert to this day) that no sighting “…could be considered an extra-terrestrial vehicle [and] throughout Project Blue Book there was never a shred of evidence to indicate a threat to our national security.”

grudge green fireball memo