Washington National Airport Radar Files is the source set for the July 1952 Washington, D.C. radar-visual incidents, centered on Project Blue Book Case 1661 and related Civil Aeronautics Administration, Air Force, and CIA records.123
Record Provenance
The National Archives identifies Project Blue Book as the declassified U.S. Air Force UFO investigation record set, including 37 cubic feet of chronological case files and access through 94 rolls of 35mm microfilm.1
The T1206 microfilm guide places case numbers 1495 through 1673, covering July 19 through July 28, 1952 from Rock Island, Illinois to Washington, D.C., on roll 12, which is the archival neighborhood for the Washington National radar sequence.2
The circulated Case 1661 scan identifies itself as Project Blue Book Case 1661, box 35, Record Group 341, Records of the U.S. Air Force, and describes the file as "Washington National Sightings" for July 1952.3
CUFON's Washington National Sightings File states that its page contains the text of Project Blue Book Case 1661 obtained from NARA, the CAA radar technical report, and a reference list, making it a near-primary finding aid rather than a single-origin government release.4
Incident Origin
The core Air Force narrative begins with unidentified targets on the night of July 26-27, 1952, observed on Air Route Traffic Control Center and tower radar at Washington National Airport and on Andrews AFB approach-control radar, with visual reports also reaching Andrews, Bolling, and the ARTC center from commercial and CAA aircraft.3
The report explicitly warns that it could not collect all facts into one report: two F-94 interceptor flights had been dispatched from New Castle, Delaware, but their official reports had not reached the office, and the commercial and CAA pilots who reported visual observations had not yet been contacted.3
The file also preserves retrospective comparison with the earlier July 19-20 weekend, noting that controllers considered the later returns more haphazard but also said unidentified returns had never before appeared in such quantities, over such duration, and with such definition as on the nights of July 19-20 and July 26-27.3
Project 1947's chronology is useful as an independent source index because it separates AFOSI, Air Force Intelligence, CAA, and NICAP-derived entries, placing the July 19-20 and July 26-27 Washington-area radar-visual reports inside a broader July 1952 wave.5
Radar and Witness Contents
Case 1661 describes varying numbers of targets, up to 12 simultaneously, on ARTC radar, with CAA personnel calling many returns generally solid and similar to aircraft returns except slower; the equipment is listed as VG-2 radar at ARTC and ASR-1 radar in the tower.3
Named CAA radar crew and controller personnel in the file include Austin M. Stapf, Lloyd Sykes, James M. Ritchey, Harry Barnes, James M. Copeland, Stewart Dawson, Phil Ceconi, Mike Senkow, and Jerome Biron, with the report characterizing the group as serious, conscientious, sincere, and fairly reliable.3
The 2130 EDT tower transcript records Washington Tower telling Andrews Tower that a large target was crossing near Andrews, with Andrews reporting additional targets northeast and south of the field while the center worked a National Airlines aircraft around targets.3
The strongest internal tension in the file is meteorological: Lt. Holcomb checked the airport weather station and found a slight surface-to-1000-foot temperature inversion, but he judged that the targets then visible on the scope were not caused by that inversion and requested a second intercept flight.3
Later statements from Andrews AFB record that most witnesses saw targets on radar rather than visually, with one Andrews radar operator describing numerous targets coordinated with Washington ARTC, erratic courses, stops, reversals, brief accelerations, and sudden disappearances and reappearances several miles along the same course.3
Explanation Track
The CAA's May 1953 Technical Development Report No. 180, by Richard C. Borden and Tirey K. Vickers, investigated unidentified moving targets observed on CAA air traffic control radars through interviews, official records, and first-hand observations on Washington MEW and Indianapolis ASR-2 radar.6
That report concluded that many such radar targets correlated with surface temperature inversions and were probably secondary radar-beam reflections produced by localized refracting areas moving with wind near inversion levels.6
The CAA report is important but not equivalent to the whole case file: CUFON notes that it concentrates on the previous Washington weekend and August 1952 observations rather than the more famous July 26 sequence preserved in Case 1661.46
The official Air Force after-position, as summarized by NARA's Project Blue Book fact sheet, was broader than this incident: Blue Book closed with no finding that unidentified reports showed a national-security threat, advanced technology beyond present science, or extraterrestrial vehicles.1
Official and Intelligence Afterlife
The July 29, 1952 Pentagon press conference by Maj. Gen. John A. Samford became part of the later Blue Book administrative file set; the T1206 guide lists a "Press Conference - Gen. Sanford 1952" folder in the administrative files, and a public-domain transcript copy is separately preserved on Wikimedia Commons.27
CIA historian Gerald K. Haines later summarized the Washington episode as a July 1952 alarm point for the Truman administration: radar scopes at Washington National and Andrews tracked blips on July 19-20, the blips reappeared on July 27, interceptors found nothing, and the Air Force offered temperature inversions as a possible explanation.8
The CIA-sponsored Robertson Panel placed the Washington, D.C. area case of July 19, 1952 among significant sightings discussed in detail, then concluded that no direct national-security threat was evident while warning that UFO reporting could overload defense and communication channels.9
For this archive, the source value is not that the file proves a single physical object or a single weather effect. Its value is that it preserves a traceable chain: contemporaneous radar-controller reports, tower-to-tower dialogue, named CAA personnel, Andrews statements, intercept handling notes, weather checks, and later official explanation channels in one auditable source family.1234689