Show aviation future linked with tiny invisible air film now new york the rhe future ot of aviation is linked with tin on invisible film of air only a few hundredths of nn an inch thick so jo nea nearly aly perfect Is tho the streamlining of modern airplanes that even the protruding heads of tiny rivets can cut miles an hour from the speed of a plane and greatly lower its flight performance the crucial air film is known as the laminar boundary layer between tho the wing ot of a plane piano and tho the air through which it flies files it if the air passes smoothly over tho the wing an all la Is well if the air b becomes becomes turbulent air resistance is increased and speed and climbing ability aro are do decreased great advances in knowledge of tho the behavior of this invisible air boundary have been made possible by studies in wind tunnels but now it Is becoming apparent that the day may bo be approaching when wind tunnel tests alone will not be the last word in aeronautical research V free ree flight study needed speaking at tho the first wright brothers lecture of tho the institute of sciences hero here tho the british air expert prof B melville jones of cambridge university pointed out that tree free flight study of real airplanes may soon oon supply the final chock on research flight in smooth air freo free from small scale turbulence is needed he indicated to disclose some come of the parasitic air friction losses now being studied A slight unsteadiness ma may persist in wind tunnels which produces effects differing from those of actual flight key point of investigations is a study of the so called transition point where the smooth laminar low flow of air turns into the turbulent pattern that robs planes of their performance the transition point should occur as far back on the wing away from the leading edge us as is possible in free flight tests professor jones disclosed a thin layer of tinfoil only one five hun of an inch thick was sufficient to shift the transition point forward and produce drag |