Viewing page 14 of 84

This transcription has been completed. Contact us with corrections.

[[image - a Wright glider in flight]]
NEW TABLES OF LIFT were incorporated into the glider-kite in 1902, solving the problem of equilibrium and making them ready to install an engine for the final step from glider to powered flight. 

man's sons. They had to make a living, and worked as printers and bicycle repairmen before opening their own bicycle repair shop in downtown Dayton. 

In their spare time, too, they were still studying all they could find on the subject of flight. 

For by now they were possessed by the same dream that had fascinated so many men before them. But always practical, inquiring, creative, they were not mere dreamers. They had read the works of Mouillard, who in recording his thirty years of bird study had expounded theories as to how birds fly; and the great German glider pilot Lilienthal-the birdman who donned wings, raced down sandhills and coasted into the air until he was killed in a crash in 1896. The same year the brothers read accounts of the gliding tests made by Octave Chanute and A.M. Herring on the shores of Lake Michigan. And the two bicycle mechanics who had not finished high school were developing their own ideas. Industrious and conservative, they, too, wanted to be glider men, to build their own machine, to fly. 

Lilienthal had balanced his machine merely by shifting his body. The Wrights, as Orville would write years later, believed this method "incapable of expansion to meet the requirements of flight." They set out to develop a more effective system.

GLIDER FLIGHTS

To the wind-swept sands of Kitty Hawk, North Carolina, they came with their glider, beginning in 1900 and continuing every summer for three years, determined to solve the problem of equilibrium, a way of making air lift the falling wing of a machine when it tilted to one side. In Dayton they built a small wind tunnel six feet long and sixteen inches square. In it they tested literally hundreds of wings.

In their approach to the problem, the Wrights sharply differed from some of their eminent predecessors. Maxim and Langley tried for automatic equilibrium with the pilot acting as little more than a driver. The key that Wilbur and Orville discovered after exhaustive study both in wind tunnel experiments and glider flights at Kitty Hawk and Kill Devil Hill, North Carolina, was to warp the wings at the trailing edge and then, when a wing dropped below horizontal, having the pilot move a control which caused the trailing edge to bend downward slightly, offering increased lift to that side. At the same time, the wing on the rising side was warped upward to reduce lift, this causing the rising side to drop. The combined forces tended to balance the plane. 

Having solved this problem during their 1902 trip to Kitty Hawk, they were now ready to install an engine-to take the final step from glider to powered flight. 

POWERED FLIGHTS

The problem was to reduce the ratio of weight to horsepower. They had calculated the necessary specifications, concluding that they needed an eight-horsepower engine weighing no more than 200 pounds. But there was no such gasoline engine on the market. So, during the next year, they set out to build one. What they produced was a four cylinder, twelve horsepower, water cooled engine weighing slightly over the two hundred pound maximum weight they had calculated. 

In their wind tunnel experiments, the brothers had studied propellers as well as wing models. Prior to their work little research had been done in this field. And the Wrights found it their most difficult job. 

"What seemed at first a simple problem," Orville would later write, "became more complex the longer we studied it." 

A hint that they were approaching success was given by Wilbur during the summer of 1903 in an address to the Western Society of Engineers meeting in Chicago.

"By long practice the management of a flying machine should become as instinctive as the balancing movement a man unconsciously employs with every step in walking, but in the early days it is easy to make blunders ... Progress is very slow in the preliminary stages, but when once it becomes possible to undertake continuous soaring, advancement should be rapid. Under special conditions it is possible that this point is not so far away as might be supposed."

PAGE 12    THE AIR LINE PILOT