Documents / FOIA release
This is a 1992 CIA History Staff monograph by Gregory W. Pedlow and Donald E. Welzenbach, originally classified Secret NOFORN and approved for release in 2013. It covers the CIA's manned overhead reconnaissance program from 1954 to 1974 and the two aircraft it developed, the U-2 and the A-12 OXCART. The history covers the U-2 overflights of the Soviet Union, the 1960 downing of Francis Gary Powers and later operations in Asia and Latin America. It also includes a section on U-2s, UFOs and Operation BLUE BOOK.
“US Navy”15 pages
Secret NOFORN
Chapter 3
130
the aircraft, was a small-gauge wire with precisely spaced ferrite beads. The wire and beads were supposed to capture incoming 70-MHz radar pulses and either trap them in the loop or weaken them so much that they would not register as a valid radar return. This configuration was called the trapeze and was not very successful.
A second approach, tested in early 1958, involved the use of plastic material containing a printed circuit designed to absorb radar pulses in the 65- to 85-MHz range. Nicknamed "wallpaper," this material was glued to parts of the U-2's fuselage, nose, and tail. Although the "trapeze" and "wallpaper" systems provided protection against some Soviet radars, the systems proved ineffective against radars operating below 65-MHz or above 85-MHz. Furthermore, both of these additions degraded the U-2's performance. The weight and drag of "trapeze" reduced the aircraft's operating ceiling by 1,500 feet, and "wallpaper" sometimes caused engines to overheat. $ ^{74} $
SEI's research results were tested by another firm known as Edgerton, Germeshausen & Grier (EG&G), which was also composed of MIT faculty members. Under an Air Force contract to evaluate radars, EG&G operated a small testing facility at Indian Springs, Nevada, not far from Area 51. Although Kelly Johnson had been closely involved with the radar deception project since its early days, he cooperated reluctantly because he disliked adding attachments that made his aircraft less airworthy. (Johnson's dislike of the antiradar attachments was reflected in the unofficial nickname for aircraft that had been so modified—"dirty birds.") After Lockheed mechanics had mounted the various RAINBOW devices on the prototype U-2, a Lockheed test pilot would fly the plane over EG&G's Indian Springs installation. This was little more than a series of radar sets and a trailer containing instrumentation. EG&G technicians could thus record and evaluate the U-2's radar returns as it traversed a specified course over their facility. $ ^{75} $
This method of testing radar-deceptive modifications proved both time consuming and dangerous. During a test flight on 2 April 1957, the "wallpaper" modification acted as insulation around the Not linked to a story yet.
FOIA release, from the cia-readingroom collection. The PDF is mirrored here; the original link is under it. The text was read from the page images by an OCR model; expect the odd misread word. 406 pages are in the text index: search them above, or from the library's search.