“Heat Barrier” Next Phase In Air Research

Press, Volume XCII, Issue 27750, 30 August 1955, Page 13

“Heat Barrier” Next Phase In Air Research

SANTA MONICA, (California.) Aircraft speeds which will melt aluminium, steel and even diamonds are envisaged by American scientists studying the problem of the “heat barrier.*’ Whereas the once-feared sound barrier, caused by friction at high speeds, becomes progressively worse as speed increases. Specialists at the Douglas Aircraft Company’s plant at Santa Monica. California, who are seeking revolutionary new materials, say that searing heat caused by extreme speeds will melt all known metals and even turn diamonds to vapour. America has already tested an aircraft at “Mach 2”—twice the speed of sound or about 1500 m.p.h.—but far higher speeds are envisaged. The metals mainly used in present aircraft are steel, aluminium and titanium. These would all creep, expand and contract as speed increased, causing I fatal buckling and pulling away of the

aircraft’s skin. Ultimately they would melt at less than Mach 8 or about 6000 m.p.h. The hardest of metals and even diamonds would disintegrate at Mach 10 (7500 m.p.h.) The Douglas researchers say that the heat barrier can be overcome only by developing completely new materials or by operating extreme-speed aircraft outside the earth’s atmosphere, where there would be no heat-producing friction. The endless demand lor higher speeds is caused by the competition among world Powers for complete air superiority. Although the problems of the heat barrier seem remote to the man in the street, vast amounts of time, money and manpower will soon be devoted to them. According to the Douglas Company, “these solutions must be found if the United States is to produce the supersonic aircraft which will be necessary to our air supremacy in the next few years.”