The First Air Force Pilot to Die Chasing a UFO Was Actually Chasing a Secret Balloon

Locals in Simpson County, Kentucky gather at the crash site of Thomas Mantell's F-51 Mustang. (Simpson County Historical Society)

When the Air Force began seriously investigating the phenomena of unidentified flying objects (UFOs), it assigned the task to an accomplished World War II veteran.

Capt. Edward J. Ruppelt was a bombardier with five battle stars, three Air Medals and two Distinguished Flying Crosses. He took his work seriously, even if the American press chuckled about "flying saucers."

But no one was laughing after Capt. Thomas F. Mantell and his F-51 Mustang crashed into a Kentucky farm in January 1948. Mantell and his flight had engaged a mysterious object floating over the area. After going in for a closer look, Mantell went silent, and his aircraft plummeted to the ground.

The death of an accomplished pilot and decorated World War II veteran changed how America perceived UFOs. It marked the first time the public began to think that UFOs were not only real, but also that extraterrestrials might not be friendly.

On the afternoon of Jan. 7, 1948, Tech. Sgt. Quinton Blackwell received a call in the control tower of Godman Army Airfield at Fort Knox, Kentucky. The highway patrol reported a strange object floating above a farm in nearby Maysville. No one at Godman, including the base commander, could identify it.

At 1445 that day, a flight of four Mustangs under flight leader Mantell was dispatched to check out the object, which appeared to be hovering. Mantell radioed the tower, saying he would investigate.

The P-51 Mustang had just been redesignated as the F-51 Mustang, as seen in this Air National Guard photo. (U.S. Air Force)

Mantell climbed to 15,000 feet and reported the object was "metallic and it is tremendous in size." It was moving at half his speed, even as it hovered above him. The pilot then said he would climb higher. He ascended to 22,000 feet, but his wingmen hung back because they didn't have oxygen equipment. Mantell didn't either, but he continued to climb.

At 1510, Mantell was the only pilot still chasing the object. The last time anyone saw his plane, he was still ascending. Five minutes later, everyone lost visual and radio contact with him. At 1553, the object disappeared. Search-and-rescue teams discovered Mantell's remains and the wreckage of his airplane scattered across a half mile on a nearby farm. His watch had stopped at 1518.

The Army determined that Mantell lost consciousness when he tried to climb above 20,000 feet without oxygen equipment. Witnesses on the ground reported a plane circling in a dive before crashing. The wreckage revealed that the pilot's canopy lock was in place, meaning he didn't try to bail out. All signs pointed to Mantell being unconscious and unable to control the aircraft.

As for the object, the incident was first investigated by the Air Force's Project Sign, a precursor to Blue Book. Mantell's death caused a media frenzy, and the Air Force needed a quick explanation for the press. They told reporters that Mantell died while chasing the planet Venus, since it was in the sky at the time and was the brightest object.

This absurd reasoning was accepted, despite the incident occurring in midafternoon when Venus was a small pinpoint of light in the sky. For more than a year, newspaper editors accepted the Venus explanation. In the Air Force, it became the most researched UFO case to that point.

Ruppelt, the officer who would take over all Air Force UFO investigations, called the investigation a "masterpiece in the art of weasel wording."

Capt. Edward J. Ruppelt (center) would release Project Blue Book's final UFO report in 1956. (U.S. Air Force)

He took over Air Force UFO investigations in 1951, and one of his first tasks was revisiting the 1948 Mantell Incident. Project Sign had been renamed Project Grunge by this time, and Ruppelt reorganized and reinvigorated UFO investigations. Ruppelt's final report, The Report On Unidentified Flying Objects, details how he picked apart the initial investigation.

The Ohio State University astronomer who first created the Venus theory, Dr. J. Allen Hynek, immediately recanted the idea once Ruppelt began reinvestigating the crash. Since Hynek rejected the possibility that Venus was Mantell's target, Ruppelt went back to square one, looking at eyewitness descriptions of the object itself.

Based on these accounts, including that of an astronomer at Vanderbilt University who saw the UFO with a telescope, he concluded that it was most likely a Skyhook balloon, a secret U.S. Navy atmospheric testing program that used high-altitude balloons to collect data.

When Mantell was climbing to intercept the object, there was no way he would have known about Skyhook. Ruppelt believed that a balloon was launched from Clinton County Air Force Base, Ohio. The balloons were metallic and enormous, consistent with Mantell's description of the UFO. It was the most likely explanation, much more likely than chasing the planet Venus.

Skyhook and its balloons were part of the Office of Naval Research's Project Stratoscope. (U.S. Navy)

Ruppelt would stay on as director when the UFO investigation was renamed Project Blue Book in 1952. In 1960, he died of a sudden, unexpected heart attack at age 37.

-- Blake Stilwell can be reached at He can also be found on Twitter @blakestilwell or on Facebook.

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