Timeline of 1952 UFO Flap>In Air Force terminology a “flap” is a condition, or situation, or state of being of a group of people characterized by an advanced degree of confusion that has not quite yet reached panic proportions. – The Report on Unidentified Flying Objects by Edward Rupelt (1956)>“flaps” as flurries of ufo activity (sometimes quite intense) confined to comparatively localized areas. .. the whole of the. rest of Britain and Europe was similarly effected by ufo visitations simultaneously, then a true ufo “wave” could be said to be taking place. Ufo “waves” also tend to occur on a cyclic basis – UFO Register - Vol 07 parts 1-2 1976–pp24-321952/01 Civil Aeronautics Administration Radar
. >“By 1952, the CAA had begun its first routine use of radar for approach and departure control.” – https://en.wikipedia.org/wiki/History_of_radar#Civil_aviation_radars1947-1952/07 ASR-1 Departure Radar
It can't see past the airport and so it is used to control planes departing the airport.>On January 7, 1952, after five years of testing and modifications to a radar system used by the Army and Navy in World War II, the Civil Aeronautics Administration inaugurated radar departure control procedures at its Washington National Airport. Six months later it began radar approach control procedures at the airport. – https://www.faa.gov/about/history/milestones/media/radar_departure_control.pdf and http://aireform.com/resources/faa-history-pages/faa-history-1950s/>Their efforts succeeded and in January 1952, the CAA officially commissioned radar departure control at Washington National Airport using an ASR-1 Airport surveillance radar developed for especially for the CAA. – https://www.faa.gov/about/history/milestones/media/radar_departure_control.pdf
ASR-2 does not seem to have been installed.1952/07 ASR-3 Approach Radar with Improved Antenna>During the fiscal year 1952 [1952/07-1953/06] … Development of a substantially more accurate omnirange antenna, in corporating an electrical polarization screen, was completed. – The Annual Report of the Secretary of Commerce, Volumes 40-47: OFFICE OF THE UNDER SECRETARY FOR TRANSPORTATION https://babel.hathitrust.org/cgi/pt?id=uc1.a0002110831&view=1up&seq=63>The Antenna of the Airfield Surveillance Radar ASR 3 was presented on an exposition in Berlin in 1953. First international installation was on Airport Bombay (India) in 1961. – https://www.radartutorial.eu/19.kartei/11.ancient/karte015.en.html1952/07/19-20 Washington, D.C. UFO incident
The install timing of "approach radar" is constrained by the Washington National Airport traffic control detecting the https://en.wikipedia.org/wiki/1952_Washington,_D.C._UFO_incident
. So the install date is between July 1-19.
The major peak of the UFO flap is between about 1952/07/12 to 1952/08/08. Which means radar could have been responsible for the uptick in reports. I tested this by doing a chart for only basic witness-only sightings, but the uptick still existed. 1952/07/29 CIA>We now know, of course, that in 1952 the CIA had recommended that a certain amount of mischief be introduced into private UFO societies following the wave of UFOs over Washington, D.C., which had compromised national security (or so it was said at the time). The story might have died with a very frightened and silenced Bender were it not for Gray’s explosive and entertaining book about the Bender case, They Knew Too Much About the Flying Saucers. – The Silver Bridge by Gray Barker (1970).>Until the summer of 1952, the CIA had little interest in flying saucers. With the 1952 flap and the Invasion of Washington, however. this changed. On July 29 (the day of General Samiord’s press conference), Ralph L. Clark, Acting Assistant Director for Scientific Intelligence, wrote a memo to the Deputy Director for Intelligence. It said:>>In the past several Weeks a number of radar and visual sightings of unidentified aerial objects have been reported. Although this office has maintained a continuing review of such reputed sightings during the past three years, a special study group has been formed to review this subject to date, O/CI [office of Current intelligence] will participate in this study with O/SI [Office of Scientific Intelligence] and a report should be ready about 15 August.
– Watch the Skies! by Curtis Peebles (1994)