National Geographic : 1938 Jul
MEN-BIRDS SOAR ON BOILING AIR BY FREDERICK G. VOSBURGH ONE chilly February afternoon, a pioneer American glider pilot, Jack O'Meara, cut loose from a towing airplane over New York City and headed his ghostly ship down the East Side. He was trying to show that a man could ride on the warm breath of a city. Every furnace, every person, every taxi cab exhaust, is giving off its share of heat, and the heated air is rising-so reasoned O'Meara and his glider-conscious friends at the Glenn Curtiss airport on Long Island. Manhattan, completely water girt, should be a chimney of ascending air on which the skillful pilot could soar at will. This was the theory. Now for the test. ALOFT-ON THE BREATH OF A CITY With no sound but the sighing of the wind in its wings, the motorless plane glided southward along the eastern margin of Manhattan's masonry canyons. Commerce Department officials at Washington had warned O'Meara against wandering too near the heart of the city. They didn't want him colliding with a skyscraper or cracking up on somebody's roof. By the time it neared the Chrysler Building, the glider had sunk considerably from its original 3,800-foot altitude-and O'Meara's heart had sunk with it. The flight seemed a failure. Banking sharply, he headed across the East River toward the airport some five miles away. How could he ever hope to make it? The ship was losing altitude alarmingly and it looked like a certain crack-up, either in the river or among the houses and fac tories on the Long Island side. But O'Meara's glide carried him across, and the warm air from a cluster of smoke stacks gave him a temporary boost. Then all at once the flyer felt himself rising. A strong upward current was carry ing him skyward-to two thousand, three thousand, four thousand feet. He had struck the warm breath of the mighty city, not over Manhattan itself but over Long Island, across the East River, where this enormous heat-created, or "thermal," cur rent had been blown by the west wind. High aloft, the light-hearted O'Meara exulted. The theory was vindicated, and it was an easy glide now to the home airport. Before coming in to a perfect landing, he dipped and bobbed in triumph. Riding thermals was a novelty then, more than seven years ago. HUNDREDS OF MILES WITHOUT MOTORS Today the flights of many such auda cious soarers have so increased knowledge of the air and its currents that sailplanes, as high-performance gliders are known, have been flown several hundred miles and others have reached altitudes of more than two miles above their take-off point. Much of the remarkable progress in soar ing has come about since 1929, when the NATIONAL GEOGRAPHIC MAGAZINE pub lished the first extensive article in America on flying without an engine.* At that time motorless flying was con fined chiefly to Germany, where an air minded nation had turned to gliders and sailplanes when denied power-driven planes under the Versailles Treaty. Pilots placed chief dependence on simple "slope winds," the inverted waterfall of air produced when a breeze hits a hill and shoots upward. Now the sport of soaring is world-wide, and the harnessing of various types of air currents, even those that accompany thunderstorms, has resulted in hitherto un heard-of achievements. Engineless planes have actually flown farther and higher than the best power driven planes had flown up to about 1911. NEW WORLD RECORDS A Russian, Victor Rastorgoueff, last year flew a world's record straight line distance of 405 miles. The average speed of his motorless ship was more than 48 miles per hour. Another Russian pilot, V. M. Iltchenko, covered 253 miles carrying a passenger. Kurt Schmidt, a German, soared over the sand dunes of East Prussia for a day and a half-36 hours and 35 minutes. Another German, Heinrich Dittmar, sailed into the clouds above Campo dos Affonsos, Brazil, and rode the turbulent gusts of an incipient thunderstorm to a height of 14,190 feet above the point where * See "On the Wings of the Wind," by Howard Siepen, in the NATIONAL GEOGRAPHIC MAGAZINE for June, 1929.