Mantell 1948: a fatal climb, three versions of the last radio call, and a balloon no one could trace

On 7 January 1948 Capt. Thomas F. Mantell, Jr., leading a flight of National Guard P-51s, climbed after a bright object hanging south of Godman Field, Kentucky, and died in a crash at Franklin. The case files record his last radio call in different ways, and the Air Force's explanation moved from Venus to a balloon that no one could trace.

37.9069° N · 85.9719° W · Godman Field · Fort Knox, KY · 7 Jan 1948

Source: NARA Archive

Calls from the state police

The Project Blue Book summary of the Godman Field tower log starts at about 13:20 on 7 January 1948. A sergeant from the commanding officer's office told T/Sgt Quinton A. Blackwell in the control tower that, according to the Fort Knox Military Police and the Kentucky State Police, a large circular object about 250 to 300 feet in diameter was over "Mansville, Ky." Army Flight Service reported nothing, but further reports soon placed the object over Irvington and then Owensboro. Blackwell first saw something himself at about 13:45 to 13:50, south of the field, and the base commander, Col. Guy F. Hix, saw it at about 14:20 ^[4].

Capt. James F. Duesler, Jr., who went up to the tower with Lt. Col. E. G. Wood at about 14:20, said in a statement dated two days later that he first saw a bright silver object there ^[6]. The Air Materiel Command's first Project Sign report, dated 23 April 1948, lists eight separate reports from that day as incidents 33 to 33g. Their times run from 13:20 CST at Godman to 18:54–19:06 at Madisonville, Kentucky, and only one, 33f at 14:45, was observed from the air ^[1]. Ruppelt later noted that the tower witnesses could not agree on what they saw, describing everything from "a parachute" to "an ice cream cone tipped with red" ^[10].

an object hanging high in the sky south of Godman

— Capt. James F. Duesler, Jr., statement of 9 January 1948 [6]

The chase

At about 14:30 to 14:40, the tower summary says, four P-51s approached Godman from the south on their way from Marietta, Georgia, to Standiford Field, Kentucky. Blackwell asked the flight leader, NG 869, to try to identify the object. He went south with two of the other planes, and the fourth continued to Standiford alone ^[4]. Duesler named the flight leader as Capt. Thomas F. Mantell and recorded that the pilot who left had said it was time for him to land ^[6].

According to Duesler, Mantell reported 7,500 feet and climbing, then called out an object at twelve o'clock high that was bright and climbing away from him, moving at about half his speed, roughly 180 miles per hour. Later he said he was at 15,000 feet and still climbing after it, and judged its speed to be the same as his own. When another pilot asked him to level off, the tower heard no reply ^[6].

The tower summary puts Mantell's last call, that he was trying to close in for a better look, at about 15:15. Five minutes later the other two planes turned back. One of their pilots, NG 800, said the object looked like the reflection of sunlight on an airplane canopy; he later searched again, up to 33,000 feet and 100 miles south, and saw nothing ^[4]. A 1964 Blue Book letter to the coroner of Simpson County records that an aircraft accident occurred at Franklin, Kentucky, in January 1948, and that the county coroner examined the body of the pilot, Captain Thomas F. Mantell, Jr. ^[7].

What did he say?

The phrase most associated with the case, that the object was metallic and of tremendous size, appears in only one of four accounts of the radio traffic that the investigators collected. Col. Hix remembered only the object travelling at 180 miles per hour, half the pilot's speed. 1st Lt. Orner heard "high and traveling about 1/2 my speed at 12 o'clock position" and then "Closing in to take a good look". Capt. Cary W. Carter recalled the object going up and forward as fast as the pilot and the words "going to 20,000 ft and if no closer will abandon chase". Only Blackwell's version includes the metallic description ^[5]. Duesler's statement does not mention it either ^[6].

Intelligence studies repeated Blackwell's wording anyway. An Air Intelligence Division study dated 10 December 1948 described a National Guard pilot killed while chasing an unidentified object "up to 30,000 feet" and quoted his last message to the tower as "it appears to be metallic object.... of tremendous size" ^[2]. That altitude is not given anywhere in the radio accounts, which stop at 15,000 feet and a stated plan to go to 20,000 ^[5]. Ruppelt later wrote that everyone in the tower agreed on "I'm going to 20,000 feet" but not on the part about the object being metallic and tremendous ^[10].

It appears metallic of tremendous size.

— NG 869 (Capt. Mantell), as recalled by T/Sgt Quinton A. Blackwell [5]

Venus, then a balloon

The first explanation was the planet Venus. In August 1948 a bright object seen from Godman, which an F-51 flying over the base at 30,000 to 35,000 feet could not locate, was identified as Venus by an astronomer at the University of Louisville, and the Air Force study that reported this added that the earlier Godman incidents may also have been Venus ^[3].

Astronomer J. Allen Hynek's analysis for the Air Force, printed in the 1949 Project Grudge report, was more cautious. He wrote that the evening sightings on 7 January were undoubtedly Venus, but that no single explanation of the daytime sightings worked without relying heavily on coincidence. He suggested more than one object had been involved, possibly Venus in the fatal chase and balloons elsewhere ^[9]. He also noted an unofficial report that the object was a Navy cosmic ray balloon ^[8].

If this can be established, it is to be preferred as an explanation.

— J. Allen Hynek, Project Grudge report, Appendix B, 1949 [8]

Ruppelt's answer

Edward J. Ruppelt, who ran Project Blue Book, reopened the case in early 1952 after a query from the Pentagon. He found that the 1949 microfilm of the file was partly ruined. Hynek told him he did not think the object was Venus, because the planet would have been only about six times as bright as the surrounding sky. Ruppelt then considered the 100-foot-diameter Skyhook balloons, a project he described as highly classified at the time. Wind data he obtained showed that a balloon launched from Clinton County AFB in southern Ohio could have passed the Kentucky towns in the order the reports came in and then drifted south of Godman ^[10].

He never found a launch record for a balloon on 7 January 1948, and people who had worked on the early Skyhook flights would say only that one was possible. Retellings that present Ruppelt as a dissenter who privately considered the case unexplained have it backwards: in his own 1956 book he argued that assuming a balloon makes the whole picture fall into place, and the answer he phoned back to the Pentagon favoured the balloon ^[10]. The file is also thinner than legend suggests. Blue Book's 1964 letter to the coroner states that the Wright-Patterson case file held information on the wreckage but nothing on the pilot's condition ^[7].

It could have been a balloon.

— Edward J. Ruppelt, The Report on Unidentified Flying Objects, 1956 [10]

Last fact-checked: 2026-10-03. Every claim cites its source.