The Paper-Plane Caper

Until 1968 Richard Kline's only experience with aeronautical engineering was folding paper airplanes for his young son Gary. Then one day, Kline, an advertising agency art director in New York, stumbled on a radically new design; it flew more stably than any previous model, and a lot farther as well. He showed the airfoil to a pilot friend, Floyd Fogleman, who concluded that Kline had inadvertently discovered "a whole new concept in aerodynamics."

That claim may not be as high-flown as it sounds. Dr. John Nicolaides, professor of aerospace engineering at the University of Notre Dame and a former NASA official, also became a believer after Kline sailed a model of his new glider practically the length of Notre Dame's practice football field. In subsequent wind-tunnel tests, the scientist confirmed what Kline already believed: that his wing was a true breakthrough in aerodynamic design, one that greatly resists stalling. Exactly why that is so remains a mystery.

Kline, 42, credits his very ignorance for the discovery. ''Anybody who knew anything about aerodynamics would have said, 'Forget it, it won't work,' " he grins. "Me, I never even heard of Bernoulli's principle." That dictum, upon which all conventional airfoils are based, says that the faster a gas or fluid flows, the less pressure it exerts. As an aircraft wing is thrust forward, the flow of air over the curved upper surface is faster than the flow past the flat underside. Thus there is more push from beneath the wing than on the upper surface, where pressure is reduced; that "lift" keeps planes aloft.

Instead of being curved like most airfoils, Kline's wing is completely flat, at least on top. From the leading edge to almost halfway back, the cross section of the wing gradually thickens into a wedge. Then, the underside sweeps abruptly upward. It is this step that apparently gives the design its advantage over conventional airfoils. Tests show that it can provide lift even when it is tilted at an angle far greater than 19DEG to the onrushing air; it is around that angle that conventional wings begin to lose their lift, causing stalls.

Paper-plane builder Kline is sure that he has somehow violated Bernoulli's principle. "Sorry, Bernoulli," he says, "but our airfoil just doesn't work that way." But Aerodynamicist Nicolaides gently points out that there is still a pressure differential between the top and bottom of the wing caused by differences in air flow, although he is not yet sure how this is achieved.

In any case, Kline and Fogleman have not let theoretical questions stand in their way. Sensing the commercial possibilities of the wing, the two have spent some $14,000 on research and development. They also came very close to alienating their wives. "When he'd fly that thing he drove me nuts," recalls Jane Kline. "I was forever ducking around the house. Those models were always coming at me." As expected, Gary, now eleven, was solidly behind the project from the beginning. He frequently accompanied his father on test flights to baseball fields and parks, even to his father's 24th-floor office. There, the senior Kline sailed his planes out the window to a park below.

Enthusiastic as ever about the design, Kline and Fogleman would like to license manufacturing rights, possibly to an aircraft company. They are also considering mass-producing the paper wing as a toy. Whatever use they finally make of it, Kline's creation has already achieved a distinction: it was recently granted U.S. patent No. 3,706,430, perhaps the only one ever derived from a paper airplane.

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