Documents / Official release
This 1947-dated Project Blue Book case file from the Air Materiel Command's Technical Intelligence Division contains an illustrated piece titled "Saucers Over Washington, D.C." It covers the radar sightings at the Washington National Airport control center on the night of July 19, 1952. Senior controller Harry G. Barnes reported at least 10 unidentified objects, and Capitol Airlines pilot C.S. Pierman saw lights that matched the radar returns. The piece disputes the Air Force's temperature inversion explanation, noting the inversion was only one degree.
Read from the scan by GLM-OCR; expect the odd misread word.
BARNES THEN STATES: "BEFORE NOTIFYING THE AIR FORCE... OUR TECHNICIANS HAD CAREFULLY CHECKED THE EQUIPMENT TO MAKE CERTAIN THAT IT WAS OPERATING PERFECTLY... " THERE IS NO OTHER CONCLUSION I CAN REACH BUT THAT FOR SIX HOURS ON THE MORNING OF THE 20TH OF JULY THERE WERE AT LEAST 10 UNIDENTIFIABLE OBJECTS MOVING OVER WASHINGTON. THEY WERE NOT ORDINARY AIRCRAFT. I COULD TELL THAT BY THEIR MOVEMENT ON THE SCOPE..." "I CAN SAFELY DEDUCE THAT THEY PERFORMED GYRATIONS WHICH MOKNOWN AIRCRAFT COULD PERFORM. BY THIS I MEAN THAT OUR SCOPE SHOWED THAT THEY COULD MAKE RIGHT ANGLE TURNS." "...AND COMPLETE REVERSALS OF FLIGHT..." NOR IN MY OPINION COULD ANY NATURAL PHENOMENA SUCH AS SHOOTING STARS, ELECTRICAL DISTURBANCES, OR CLOUDS ACCOUNT FOR THESE SPOTS ON OUR RADAR NOT TO MENTION PIERMAN'S ACTUAL VISIBLE SIGHTINGS OF THE OBJECTS. EDS. THE AIR FORCE DUG DEEP IN AN EFFORT TO SQUIRM OUT OF THIS SIGHTING. AT 4'OCLOCK ON JULY 29,1952. A PRESS CONFERENCE WAS HELD... GENTLEMEN! THE RADAR-SIGHTINGS OVER WASHINGTON WERE CAUSED BY TEMPERATURE INVERSION. THE OBJECTS WERE REFLECTIONS OF GROUND OBJECTS...CARS...TRAINS...ETC.. THIS WAS THE AIR FORCE'S GLIB ANSWER. THEY DREW UPON DR. DONALD H. MENZEL'S TEMPERATURE-INVERSION THEORY: WHEN A LAYER OF COOL AIR LIES BENEATH A LAYER OF WARM AIR, LIGHT RAYS ARE REFRACTED AS THEY PASS THROUGH. IF A TEMPERATURE-INVERSION IS STRONG ENOUGH...IO TO IS DEGREES DIFFERENCE...LIGHT RAYS MAY EVEN BE REFLECTED. THIS IS WHAT CAUSES MIRAGES ON DESERTS OR HEATED ROADS, LIKE LIGHT, RADAR WAVES ARE ALSO REFRACTED OR REFLECTED." TEMPERATURE-INVERSION," THE AIR FORCE SAID, "WAS THE ANSWER." JUST TWO POINTS BOYS: (1) THE ACTUAL TEMPERATURE INVERSION OVER WASHINGTON ON THE NIGHT OF JULY 19,'52,WAS JUST ONE DEGREE FAHRENHEIT! AND (2) YOU FORGOT THE VISUAL SIGHTINGS!
Official release, from the nara collection. The PDF is mirrored here; the original link is above. The text was read from the page images by GLM-OCR; expect the odd misread word. 2 pages are in the text index: search them above, or from the library's search.