File:Invisible-Jet-Fighter-Grumman.jpg

An advertisement, scanned from the June 28, 1954 issue of Newsweek, touting the technological advancement of the Grumman Aircraft Engineering Corporation of Bethpage, Long Island, New York, "designers and builders of the Cougar jet fighter, the S2F-1 sub-killer, the Albatross amphibian, metal boats, and Aerobilt truck bodies." The advertisement reads:

This Grumman jet fighter is invisible. She is electrons. Yes day after day, she makes supersonic flights through an electronic sky.

Actually she is an electronic brain by the name of READ (Reeves Electronic Analog Computer) directed by a group of brilliant human brains. The latter convert the mathematics of the air-graft into a language they and she understand. The "tell" her everything they know about the new fighter design through wired panels and curves wired on revolving drums.

The cockpit with its human pilot is plugged in. At a signal he takes off and climbs to fifty thousand feet. The electronic air is smooth up to the transonic range where sound waves pile up until the air misbehaves. Once through, the air is smooth again, and they are ready to test a combat maneuver at supersonic speed.

"Now Decelerate."

The pilot extends speed brakes. All eyes watch the instruments, and the reactions recorded on moving graph paper.

These performance data, gained months before actual flight tests, help check designs created with results from other Grumman research. One reason Grumman planes are ready in quantity when needed.

This is part of a REAC formula worked out in the Grumman "Brain Room". Unlike digital computers which work directly with numbers, this analog computer works with forces of motion by reproducing them in volts.

The computer is "told" the facts of the problem through miniature switchboards. A different problem can be made known to the computer quickly, simply by changing boards.

Some data, like wind tunnel results, are fed into the computer from revolving drums. The computer gets its information electrically from copper wires glued over penciled curves.

These (lowest right) are typical REAC answers. Engineers translate these squiggles into design information. Sometimes thousands of such answers may be required to solve any one of the many design problems.