National Geographic : 1943 Oct
How Precise is Precision? Maybe your yardstick is a fine watch. Ours is a Ranger 12-cylinder in-line, air-cooled engine. See the comparisons between the two listed below. A whole battery of fine laboratory instruments, plus the genius of craftsmanship, are responsible for the Ranger's outstanding precision performance. There's the spectroscope, for example-so sensi- tive it can spot a particle of metal as minute as seven parts in a hundred thousand. Fairchild uses it to explore and to control the metals in Ranger engines. A quarter millionvolt X-Ray is another Fairchild key to secrets that are hidden beneath 4 inches of solid steel. It tells our engineers which metals can "take it." A QUALITY WATCH PARTS-about 350. PRECISION meas urements-wheel pivot held to a toler ance of1/2of1per cent of its diameter. SPEED of moving parts -balance wheel oscillates 5 times per second. Under a metallurgical microscope our technicians can read the history of any metal . . . tell how it was processed during manufacture. With electrical instruments they can detect a flaw one ten-thousandth of an inch in depth that could become a bottomless pit of danger. A beam of black A RANGER ENGINE PARTS - exactly 4,127. PRECISION meas urements-impeller shaft held to a toler ance of 1/10 of 1 per cent of its di ameter. SPEED of moving parts-fastest part revolves 520 times per second. light is played over machined surfaces to expose the structural "criminals" that may lurk within. These and hundreds of other present-day miracles are rou tine matters for Ranger engi neers and scientists. Result -the Ranger Engine... combi nation of precision and power .. another Fairchild "touch of tomorrow in the planes of today." BUY U. S. WAR BONDS AND STAMPS F AIRCHILD ENGINE AND AIRPLANE CORPORATION 30 ROCKEFELLER PLAZA, NEW YORK Ranger Aircraft Engines Division, Farmingdale, L. I. * Fairchild Aircraft Division, Hagerstown,Md., Burlington, N. C. * Duramold Division, New York, N.Y.