by James Tobin
When they made the top, they were rewarded with vistas of stark beauty. To the west lay the broad reach of Albemarle Sound, and a quarter-mile to the east, the white-capped Atlantic, where crowds of gulls and pelicans wheeled and dove. On the high dune itself there was nothing to see but the sand—no trees, no vegetation of any kind, only black swallows rising and falling. From a distance of twenty yards, the surface of the hill seemed to glow, for the wind blew the sand into a filmy sheen. If the men sat to rest, grains of sand collected in their hair and behind their ears. By evening they felt as if their skin had been brushed with chalky powder.
At the top of the hill, before each test, they would pause to catch their breath and calculate. One man would raise a hand-held Richard anemometer above his head to check the speed and direction of the wind. Another readied a stopwatch to time the glide. A tape measure was kept handy for measuring the distance. They used the clinometer from Chanute to measure the slope of the dune, and they took care to find a slope that would match the usual slope of the glider’s own path. By doing this, they could fly along the contour of the dune, practicing their skills just a few feet off the sand. That way, mistakes were likely to cause only bumps and scrapes, not broken bones or worse. There was a good deal of waiting for the wind to blow hard enough and in the right direction. When they had recovered their breath and the wind was right, they were ready for another test.
Will got in the slot in the middle of the glider. Orville and one of the assistants—Spratt or Huffaker or Bill Tate or Bill’s half-brother, Dan—would grab a strut at either end. Then, at Will’s say-so, all three would run. As the men at the ends grunted and strained, struggling for traction in the confoundingly soft sand, Will would lean forward on the frame, gripping the bars that controlled the rudder and hooking his ankles on the frame behind him. The assistants ran and hauled, straining for a little speed. Then the burden suddenly lightened as the wind and the glider met.
To Will, lying prone in the operator’s cradle, it was a moment of confusion, a mixture of bracing physical buoyancy with furious mental figuring about the effects his movements might have on the glider’s behavior. “To the person who had never attempted to control an uncontrollable flying machine in the air, this may seem somewhat strange,” he said later, “but the operator on the machine is so busy manipulating his rudder and looking for a soft place to alight that his ideas of what actually happens are very hazy.”
His first flights were puzzling.
Orville and George Spratt stood at the leading corners, grasping the uprights. At Will’s signal, the three set off in the usual lumbering sprint. Then came the release . . . and a shuddering thunk into the sand. They tried again with only a little better result; the machine, which they thought would rise far more readily than the glider of the year before, nosed downward and hit the sand perhaps fifty feet down the hill from the starting point. Hoist, run, release . . . thunk—twenty feet. Will, trying to counteract the glider’s obvious desire to nose down, wriggled backward a couple of inches to bring the center of gravity farther toward the rear. With his hands, he pushed the horizontal rudder to a sharp upward angle. With each try he moved farther back until he was sprawled across the wing, his hands barely able to control the angle of the rudder. In this awkward and impractical position, on the seventh try, he found the glider at last consenting to stay in the air.
Huffaker and Spratt looked on in delight as the machine rose and dipped for several hundred feet down the slope. Spratt had not seen anything like it. “Long flight, very good,” Huffaker jotted in his diary. They tumbled down the hill in pursuit, then hauled the machine back up. The next try produced a similar glide, with much rising and falling.
The ninth try brought a very bad moment. With Will still stretching to keep his weight near the back while gripping the control bar at the front, the machine refused to hug the sand at a safe altitude. The nose rose and rose. The glider, now twenty feet off the ground and pointed upward, was coming to a dead stop. A flash went through Will’s and Orville’s minds simultaneously—the glider was behaving exactly as Lilienthal’s had just before its fatal crash. Later, the glider’s behavior would be called a stall.
Orville cried out. Will shoved the rudder but with no effect. Will inched forward, trying to bring the nose down, and suddenly the glider was coming down—yet not with its nose first, but flat, like a parachute. It landed softly enough that Will was not even shaken. A few moments later the same thing happened, and on the final try of the day, the glider actually reversed direction, sliding backward to crunch into the sand on its tail.
The next day was Sunday, so there were no experiments. Huffaker was bubbling about the results thus far, but to the Wrights, Will’s flights would have been profoundly unsettling. A glider that was supposed to rise much more easily than their 1900 machine, and stay just as well balanced, was careering up and down, essentially out of the operator’s control. Huffaker could admire all he liked; he hadn’t been in the air, and his enthusiasm merely displayed his ignorance. “We find from Mr. Huffaker that he and Chanute have greater hopes of our machine than we have ventured to hold ourselves,” Will told Milton. “In fact they seem to have little doubt that we will solve the problem if we have not already done so, so far as the machine itself is concerned . . . Mr. Huffaker remarked that he would not be surprised to see history made in the next six weeks. Our own opinion is not so flattering. He is astonished at our mechanical facility, and as he has attributed his own failures to the lack of this, he thinks the problem solved when these difficulties are overcome, while we expect to find further difficulties of a theoretical nature which must be met by new mechanical designs.”
The only performance they were happy about was Will’s flat descent out of “the very fix Lilienthal got into when he was killed,” Orv said. (If this was meant to reassure his sister, who was not yet acquainted with the fine points of gliding, Orville could hardly have chosen his words less carefully. “His machine dropped head first to the ground and his neck was broken.”
On Monday morning the glider performed a strange new trick, nosing downward unaccountably. The Wrights went to work on the horizontal rudder, reducing its size, but it made no difference. Orville took a turn in the operator’s position, perhaps for the first time. His flight was steadier than Will’s attempts of that day but still disappointing. Testing the machine as a kite only compounded the mystery. “It seems as if the tendency is to turn down as the speed increases,” Huffaker recorded—a phenomenon that utterly confounded the Wrights’ carefully calculated expectations.
They were back at the gate of the maze, bewildered by the problem of balance. In their new technical vocabulary, the problem had to do with two abstract concepts that helped experimenters discuss how to keep their artificial birds from plunging to the ground. One was the center of gravity, the point at which a wing or a glider would balance, both side to side and fore to aft. The other was the center of pressure, the point at which all the forces pushing the wing upward were concentrated. When a glider bucked and pitched in the wind, its center of pressure was racing back and forth between the front and the rear of the glider. “The balancing of a gliding or flying machine is very simple in theory,” Will wrote a few weeks later. “It merely consists in causing the center of pressure to coincide with the center of gravity. But in actual practice there seems to be an almost boundless incompatibility of temper which prevents their remaining peaceable together for a single instant, so that the operator, who in this case acts as peacemaker, often suffers injury to himself while attempting to bring them together.” The brothers were now suspecting that the relationship between the centers of gravity and pressure differed markedly from one wing to the next, depending on their sizes and shapes.
It was that mischievous center of pressure that troubled Will and Orv most as they talked all that Sunday and tried to glide again on Monday and Tuesday. To stay safe and progress beyond Lilienthal’s work, they had to establish fore-and-aft balance
without shifting their center of gravity. That meant controlling the center of pressure. In this, their plan had been simple and effective. They were building their gliders with a control surface in addition to the wings—the horizontal rudder in front. With the rudder in a neutral position, parallel to the horizon, the glider was balanced so the center of gravity was slightly forward of the center of pressure. This gave the glider a slight tendency to nose down, which kept its speed up and prevented it from stalling. When the desired flying speed was reached, the pilot would adjust the rudder so that it met the wind at a slightly positive angle. This would bring the center of pressure forward under the center of gravity. In this happy state of equilibrium, a glider could proceed through the air smoothly and safely. And by shifting the angle of the forward rudder—moving the center of pressure in relation to the center of gravity—the operator could induce the glider to pitch up or down, to rise higher into the sky or return to the ground.
In the glider of 1900, the center of pressure had remained pleasingly tame, its fore-and-aft balance reasonably stable. But in this new machine, the center of pressure was running wild. Why?
The problem, they reasoned, must lie in the curvature of the wings. Aside from the increase in size, that was the critical difference between their wings of 1901 and their wings of 1900. They had changed the curvature to be closer to Lilienthal’s design. But the new glider had less lift and was harder to control. Could Lilienthal, the greatest of all the flight experimenters, be wrong?
After more attempts on Tuesday, July 30, Will sat down to think things through, recording pros and cons with a pencil in his little palm-sized diary. On the positive side of the ledger, the glider was proving itself to be strong and resilient despite being “very severely used in some forty landings.” And, so far, it was proving to be safe, despite the great increase in wing surface over the 1900 glider. Also, the first attempts at wing-warping had rendered “all that could be desired” in maintaining the glider’s lateral balance.
By pulling cables that warped, or twisted, the wings of their 1901 glider (a) the Wrights began to control their lateral balance, later called roll control (b). The horizontal rudder (elevator) in front controlled fore-and-aft balance, later called pitch control (c). When they added a tail in 1902, they perfected their ability to turn right or left, later called yaw control, thus achieving control in three axes—roll, pitch, and yaw.
The list of negatives was longer: the shortage of lift, “not much over 1/3 that indicated by the Lilienthal tables”; the poor fore-and-aft stability as compared to the 1900 glider; the high degree of drift, which reduced the glider’s speed. It was sluggish and uncontrollable—on the whole, a disappointing machine that was leading them to doubt the very ground on which their experiments stood. “The Wrights have no high regard for the accuracy of the Lilienthal tables,” Huffaker noted.
The brothers hauled the glider into the shade of the shed and went to work. Their campmates looked on with increasing admiration. Abandoning Lilienthal’s tables, they used their instincts and reduced the curve of the wing. To Huffaker the Wrights’ swift and sure remodeling job may have been a goad, for he roused himself to get Chanute’s glider ready for testing—only to have the cardboard tubing of its framework crumple under a drenching rain. The Wrights snapped a picture of the soggy mess and later included a print among several they sent to Spratt as souvenirs of the outing. At the time, Will confided, “I took it as a joke on Huffaker, but afterward it struck me that the joke was rather on Mr. Chanute, as the whole loss was his. If you ever feel that you have not got much to show for your work and money expended, get out this picture and you will feel encouraged.”
Spratt volunteered to catch the boat to Elizabeth City for provisions. He returned with a cornucopia—ham, bacon, butter, coffee, fruit, maple syrup, even some ice. The delivery was well-timed, for Octave Chanute walked into camp the next day. If he was very disappointed with the disintegration of his own machine he didn’t say so. He had made the long trip chiefly to see the Wrights in action.
The old engineer watched as the brothers made final adjustments to the remodeled glider. The curve of the new wing was now shallower, the leading edge smoother. Kiting tests showed they now had a glider that was much closer to their original intentions for the season. Its lift was still less than hoped for, but adequate. If all went well, the brothers at last could test the wing-warping mechanism to see if their most cherished innovation would work with a man aboard.
After a week of reconstruction and kiting, they were ready for a manned trial. On August 8 the wind was raking the hills at speeds approaching twenty-five miles per hour. But they were eager for trials, and they pulled the glider out of its shed. In glide after glide, Will swooped above the slope for two hundred, three hundred feet and more, easily controlling the fore-and-aft balance of the machine, thanks to the remodeled wing. He got so he could skim along just a foot or so above the sand, making tiny adjustments in the horizontal rudder to follow the graceful curves of the slope. As his skills and confidence increased, he ventured higher. “The control of the machine seemed so good,” Will said later, “that we then felt no apprehension in sailing boldly forth. And thereafter we made glide after glide, sometimes following the ground closely, and sometimes sailing high in the air.”
Now it was not only Chanute and Huffaker but the brothers, too, who believed a breakthrough might be at hand. At last they could test the wing-warping mechanism in a machine with a lot of lift and good fore-and-aft control. If it worked, they would have the first glider that could be controlled in the air without the dangerous reliance on weight-shifting that had led to the deaths of Otto Lilienthal and Percy Pilcher.
Until now, the wing-warping cables had been tied down tight. Now they made the cables ready for use, to be controlled by the operator’s feet.
The experiments that followed were utterly confounding. On some glides, Will would rock the wing-warping control right or left and nothing would happen at all. On others, the same motion would produce a sharp turn. Two ground-skimming glides ended in near-disaster. On the first, the left wing suddenly dipped; Will shifted his weight to the right to bring the glider level. But he neglected the horizontal rudder, and the glider plunged into the sand with a shuddering jolt. Will’s body hurtled forward face-first into the rudder, splintering pieces of wood and banging his nose and one eye. A similar landing sent him tumbling head over heels.
Will and Orv had come to take it for granted that wing-warping was the key to side-to-side control. It had been central to their hopes since the day in the bicycle shop when Will had twisted the cardboard box. It simply stood to reason—if one increased the angle of the wing on the right and decreased the angle on the left, the machine should rise on the right and turn to the left in a banking motion, like a bicycle.
But this machine was doing nothing of the sort, at least not dependably. On some glides it behaved in precisely the contrary way. In his diary Will jotted: “Upturned wing seems to fall behind, but at first rises.” In those ten words lay deep disappointment and puzzlement. It was “a very unlooked for result,” Will conceded to Chanute, “and one which completely upsets our theories as to the causes which produce the turning to right or left.”
“We found that if we jerked the warping [control] back and forth rapidly the machine would make its way down the hill,” Will said later, “but if we persisted in the movement long enough to determine its real effect the machine quickly acquired such a peculiar feeling of instability that we were compelled to instantly seek the ground.” Their understanding of the whole enterprise was suddenly turned upside down, for the side of the glider with greater lift was hitting the ground first. Chanute urged them not to despair. They had achieved more than anyone else, he said—more than Chanute himself, more than Percy Pilcher and even than Lilienthal. “Yet we saw that the calculations upon which all flying machines had been based were unreliable,” Will said later, “and that all were simply groping in the dark. Havi
ng set out with absolute faith in the existing scientific data, we were driven to doubt one thing after another. . . . Truth and error were everywhere so intimately mixed as to be undistinguishable.” Apparently Lilienthal had been wrong about the proper curvature of wings. He had been wrong about lift as well; there was something wrong with his lift and drift tables. Wings simply did not behave as the German had said.
They tried a few more glides, but with no better results. Will caught a cold. Spratt left. With rain approaching from the south, they watched a buzzard sail across the flats for more than a mile without once flapping its wings—a perfect display of soaring that could only have stoked their frustration.
Now Huffaker left, too. “He looked rather sheepish on departure,” Will told Spratt later, “which I attributed at the time to the fact that he was still wearing the same shirt he put on the week after his arrival in camp.”
The brothers, too, had had enough. They broke down the camp and departed.
On the long train ride home, Will said later, “We doubted that we would ever resume our experiments. . . . When we looked at the time and money we had expended, and considered the progress made and the distance yet to go, we considered our experiments a failure.” Someday people would fly, he remarked to his brother, but the two of them would not live to see it.