Authors: Seth Shulman
From the start, Selfridge wrote, the object of the AEA was “to walk in the footprints of those who had gone before and then advance beyond.” Selfridge solicited advice from a wide range of colleagues, including everyone from William Avery, Chanute’s assistant, to the Wrights themselves. In a letter to the brothers in January 1908, Selfridge asked if they might share some particular information about their understanding of where the center of pressure fell on a wing. Wilbur’s reply, offering some advice and referring Selfridge to several other sources, would later be used by the Wrights as evidence that the AEA stole their invention, but the charge is all but baseless. While helpful, Wilbur’s letter did little but confirm what the group was quickly learning on its own.
In the effort to glean as much extant knowledge as possible, the AEA was aided by its decision to move from Nova Scotia to Curtiss’s Hammondsport shop. Not only could the group take advantage of the milder climate; they were stimulated by the large number of aviation researchers who had gravitated to the town. With the lure of Curtiss’s motors, Bell exclaimed, no other place on earth could boast “such an assemblage of genius along the line of aerial work as Hammondsport.”
Captain Baldwin, at work building his latest dirigible for the U.S. Army, had moved his entire operation to Hammondsport. Another aeronaut, Charles Oliver Jones, a former engraver, was building a dirigible powered by an eight-cylinder Curtiss engine. Lieutenant Alexander L. Pfitzner, a former Hungarian officer from Budapest, was on the scene attempting to build a lightweight monoplane, again around a Curtiss engine. And J. Newton Williams, a former typewriter manufacturer from Derby, Connecticut, had relocated to Hammondsport to build an experimental helicopter that would, eventually, lift itself several feet off the ground.
In addition, Augustus Post, secretary of the Aero Club and lifelong ally of Curtiss and the AEA, came to town upon hearing of their work and, for several months, became almost an adjunct member of the team. An independently wealthy balloonist, Post was an enthusiastic observer and a cheerful extra hand. He was also a prolific writer who would ultimately pen some of the most colorful and detailed remembrances of Curtiss’s exploits.
For all the ferment and camaraderie, though, the AEA operated in virtually uncharted territory. Everything the five men undertook had to be carefully thought out and crafted from scratch. The group needed to develop a thorough working knowledge of aerodynamics. But even more, with the help of Curtiss—and often with additional help from workers in his shop—the AEA needed to master the finer points of airplane construction, from welding metal and laminating wood to sewing fabric and crafting fasteners that could withstand vibrations without coming loose. They experimented with a wide range of materials and suppliers, sending away as far as to Japan for bamboo. At the time, there were no ready supply houses for many of the materials they required.
By early March 1908, Selfridge’s biplane, with a rudder on the
tail and a single-plane elevator on the front, was ready to be tested. The group called it
Red Wing
because they had used the same red silk that had covered the
Cygnet.
Given the time of year, they decided to mount the plane on sled runners and try to take off from ice-covered Lake Keuka.
As the craft neared completion, the U.S. Army called upon Selfridge—still a commissioned officer—to report to Washington, D.C., but despite his absence, the group moved ahead, fearing that the onset of milder weather could weaken the ice on the lake. They chose Casey Baldwin as pilot simply because, aside from the older Bell, he was the only one without skates and would thus be of little assistance on the ground crew. On March 12, 1908, before a handful of friends and acquaintances,
Red Wing,
the AEA’s first motor-powered biplane, rose to a height of about ten feet off the ground and flew for about thirty yards before its tail buckled, forcing Baldwin to land. The aircraft had accomplished no more than a large hop, but the group was elated: their flying machine had risen into the air on its own power and under the pilot’s control.
The AEA knew it was now on a promising path indeed. The team immediately wired the news to Selfridge, but detained in Washington, he would never see
Red Wing
fly. Five days later, upended from the side by a gust of wind, it crashed onto the ice. Pilot Baldwin escaped injury, but the accident destroyed the craft and its motor. It was a setback, but the AEA, hot on an inventive streak, hardly broke stride. The team was too excited by the chance to refine their design.
This time, it was Casey Baldwin’s chance to oversee the work as the AEA hit a new level of intensity as a design team. In Hammondsport, the group held discussions in Curtiss’s shop almost every evening. In the shop’s annex, which they dubbed the “thinkorium,”
they talked about everything: airfoils, atmospheric pressure, engine refinements, landing gear. McCurdy and Selfridge regularly faced off in a running debate over how best to improve a propeller’s torque—the force with which it could move the aircraft. Whenever this subject came up, Curtiss recalled later, the team knew the argument was likely “to keep up until one or the other would fall asleep.”
Bell’s influence was clearly visible in the disciplined and formal procedures the AEA adopted. Each night the minutes of the previous meeting would be read and discussed, with notes assiduously kept by Selfridge. Because members, especially Bell, often had to leave Hammondsport to attend to other business, the AEA created a weekly, typed publication to chronicle their day-to-day progress. This internal newsletter, the
AEA Bulletin,
stands as one of the most remarkable firsthand records of technological development ever produced.
A major design problem confronted the group, especially after the
Red Wing
accident: how to control their aircraft’s side-to-side motion. Indeed, lateral control was on the minds of aviation researchers around the world. As on other aeronautical matters, the AEA members showed not only prodigious inventive powers but also the strength they drew from the diversity of the team Bell had drawn together. They came up with the solution that would stand the test of time:
ailerons,
from the French for “little wings.”
Aviation historians have long debated the provenance of the idea for these stabilizing flaps. The question is of particular interest because the matter would soon stand at the heart of the bitter lawsuit brought against Curtiss by the Wright brothers. In fact, neither Curtiss nor the Wrights can claim all the credit for the invention of
ailerons. It is now clear that they had been imagined in full some forty years earlier and patented by a British inventor, M. P. W. Boulton. In 1868, Boulton spelled out the invention in detail, including the need for the flaps to tilt in opposite directions on each of an airplane’s wings to keep the aircraft laterally stable.
While Boulton’s prescient invention was fully functional, the same cannot be said for the airplane he designed, which never flew. As a result, his idea lay dormant until 1904, when a French aviation pioneer, Robert Esnault-Pelterie, experimented with two tilting, horizontal rudders in one of his glider designs. Brazilian aviator Alberto Santos-Dumont adapted much the same idea in 1906, adding two tilting, octagonal flaps into an early airplane he built
Number 14-bis
(so named because it was raised into the air for launching by his balloon
Number 14
). All these efforts predate the AEA’s use of flaps, and yet none produced successful results in the air for their creators.
Nor did the AEA know of these efforts in 1907.
*
Regardless of the rich, overlapping milieu in which many researchers sought to solve the problem of lateral control, all evidence, including Bell’s testimony, points to his having arrived independently at the idea for movable surfaces at the tips of the wing. As a seasoned inventor of great integrity, Bell was meticulous about assigning credit for his ideas. His habit was to write all his ideas in a notebook and have them promptly witnessed and notarized. He surely would have attributed the idea of ailerons if he believed he owed anyone such a
debt. As he would testify later, though, the idea for movable surfaces at the tips of the wing occurred to him from studying birds.
Certainly, the AEA knew a great deal about the problem of lateral stability by 1907. And they were familiar with the Wrights’ wing-warping technique, as well as the other details of the Wright brothers’ patent for their flying machine, which had been issued in May 1906. For example, Bell marveled in a letter to Mabel as early as June 1906 that the Wright patent—which was, technically at least, a public document that spelled out their invention—was receiving so little notice in the United States.
But, just as the early uses of ailerons indicate, the issue of lateral control had long been a secondary concern among those who strove to create an airplane. It remains a controversial point, but there is evidence that even the Wrights’ vaunted concept of wing warping had been in the aviation literature for many years. The early aviation pioneer Otto Lilienthal experimented with wing warping in a glider design as early as 1895. And, as Octave Chanute would later claim in court, the naturalist and aviation expert Louis-Pierre Mouillard had even patented a wing-warping method in 1898.
One way the Wrights’ patent was influential, though, is that the AEA took pains to steer clear of the Wrights’ idea of bending the wings of their airplane. Aware of the Wrights’ proprietary claim, the AEA looked for a separate method to keep their aircraft under lateral control. Bell in particular tackled the problem with his usual acumen. On March 20, 1908, he wrote to Baldwin from Washington, D.C., mentioning the aileron idea after mulling over the reports the team had sent him about
Red Wing
’s demise. In this letter, Bell suggests the tilting flaps, as well as several other related approaches the group might pursue. “It may be that a lengthening of one wing and a shortening of the other is what is wanted,” Bell surmises, out
lining a possible design in which an extension piece on the tip of a wing might open and shut like a fan. “This kind of action is employed by birds,” Bell writes. “I have often seen birds suddenly reef their wings, so to speak, during a sudden squall, thus diminishing the supporting area of their wings.” AEA’s goal, as Bell puts it, should be to find a way to “reef one wing and expand the other.”
The AEA quickly incorporated Bell’s novel suggestion for ailerons into the airplane whose design Baldwin oversaw. With their supply of red silk depleted, they called the craft
White Wing,
covering its wings with cotton sailcloth. The aircraft would mark a pivotal step for the AEA, including many innovations—not just the ailerons but a stronger, laminated wood propeller and the inclusion of a wheeled, tricycle undercarriage.
On May 18, 1908,
White Wing
flew for the first time, covering a distance of 85 meters with Casey in the pilot’s seat. On May 19, Lieutenant Selfridge became the first member of the U.S. Army to pilot an aircraft. Two days later, on his thirtieth birthday, Curtiss flew an airplane for the first time, setting a distance record for the group of 310 meters. Curtiss said afterward that the biggest surprise was how sensitive the plane was in the air. When he pulled back on the steering wheel, he was surprised at the way
White Wing
rose swiftly into the air. He immediately countered the effect so hard that the plane bounced to the ground. “As is usual in any balancing act,” Curtiss said later, “the novice overdoes matters…. I realized that vertical control was a very delicate thing, and although I did my best to keep on a constant level, there was more or less hitching up and down through the entire distance.”
White Wing
was the cause of much elation and pride on the part of its designers. But like its fragile predecessors, the aircraft would not last long. It made just seven flights before crashing beyond
repair with McCurdy at the controls, although he was not badly injured.
With the destruction of
White Wing,
the next AEA design fell to Curtiss and afforded the group the chance to consolidate all it had learned so far. During the first three attempts, Curtiss had mostly confined his input to the aircraft’s power plant and propellers. While the long hours and constant aeronautical discussion had drawn the team close, Curtiss was always cognizant that he was the only member without an advanced degree and so he deferred, mostly watching, studying, and learning. But he was a quick study and a remarkable hands-on engineer, improving upon past failings, learning from prior mistakes. Now he had his chance to prove it.
As Curtiss and the group worked on the plane they would eventually call the
June Bug,
the nightly conferences continued. One evening, a particularly productive discussion about the way air passes over a wing—or airfoil—led Curtiss to surprise the group by designing and building an innovative wind tunnel. A coffin-like box, it had an electric exhaust fan on one end and a radiator pulled from an automobile on the other. As Curtiss demonstrated to the group, a model wing or aircraft could be hung inside the box and observed through the glass window in the top as a swift current of air swept through the apparatus. According to one account, Curtiss, in a fit of inspiration, had Harry Genung come and puff his pipe in front of the radiator to help the group actually see the air turbulence. As the smoke was sucked into the machine, the five AEA members watched fascinated as it flowed over the little wings, making swirls and eddies around the edges. Bell called it an enormous contribution to aeronautics, and all agreed that it helped to streamline their design. They were so taken with the contraption that they failed to realize that Genung was puffing so hard on their
behalf he was making himself sick and had to be escorted outside for fresh air.
Genung’s voluminous smoke would be replaced by threads of scarlet silk that would serve the same function of highlighting air turbulence for the increasingly scientific AEA designers. And, with the help of the wind tunnel and the group’s lengthy, increasingly knowledgeable discussions, Curtiss introduced several vital modifications to the earlier AEA efforts. He lengthened the airplane’s body to improve its horizontal, front-to-rear stability. For easier storage and transportation, he devised a means to make the wings removable and to allow the tail section to be folded up. And he refined the ailerons.