Edward J. Ruppelt

Edward J. Ruppelt headed Project Blue Book from 1951 to 1953, making him the most senior Air Force officer to run the programme during its period of most active investigation. A World War II combat veteran and radar specialist, Ruppelt took command after Project Grudge had been criticised internally for dismissing reports without adequate analysis.

Under Ruppelt, Blue Book adopted more systematic procedures: standardised reporting forms, statistical methods, and consultation with external scientists including J. Allen Hynek. He coined the term "unidentified flying object" as a replacement for "flying saucer," arguing the older phrase prejudiced investigation. During the 1952 Washington D.C. radar-visual incidents, Ruppelt was unable to get authorisation to travel from Dayton to Washington to investigate in person, a bureaucratic failure he later documented in detail.

After leaving active service in 1953, Ruppelt published The Report on Unidentified Flying Objects (1956), widely regarded as the most candid insider account of the Air Force's UFO investigation programme. The book described cases Ruppelt considered genuinely unexplained and criticised both uncritical believers and reflexive debunkers.

A revised 1960 edition added three chapters adopting a more dismissive tone toward the phenomenon. Researchers have debated whether this shift reflected Ruppelt's changed views, pressure from the Air Force, or the influence of his return to defence industry work at Northrop Aircraft. He died of a heart attack in 1960 at age 37.