Mantell UFO incident

On 7 January 1948, 25-year-old Captain Thomas F. Mantell, a Kentucky Air National Guard pilot, died when the P-51 Mustang fighter plane he was piloting crashed near Franklin, Kentucky, United States, after being sent in pursuit of an unidentified flying object (UFO). Pursuing the object in a steep climb and disregarding suggestions to level his altitude, Mantell lost consciousness at high altitude from lack of oxygen; his plane went into a downward spiral and crashed. The incident was among the most publicized early UFO reports. Later investigation by Edward J. Ruppelt, Head of United States Air Force's Project Blue Book found that observations from an airforce base control tower, particularly of "a parachute" and "an ice cream cone tipped with red", as well as an astronomer at Vanderbilt University who reported "a pear-shaped balloon with cables and a basket attached", suggested that Mantell died chasing a Skyhook balloon, which in 1948 was a top-secret project that he would not have known about. The Skyhook was likely launched from Clinton County AFB.