Did the really get their idea of wing-warping from the birds? The Critical Twist

BY BRUCE D. CALLANDER

HAT did they know, and when Wdid they know it? Long before Watergate made this question trendy, it was being asked of the two Ohio brothers now ac- claimed as the fathers of aviation. The burden of answering it may have hastened the death of one. It dogged the other for life. The issue arose in 1909. The ven- ue was a patent suit. The defendant, plane-builder , had been hauled into court by Orville and Wilbur Wright, the Ohioans who six years earlier had invented the . Or had they? Curtiss provided cause for doubt. Wilbur -tests the 1902 Wright . Control of fixed-wing was reliable He charged that the "secret" of the only in calm air; neither auto-type steering nor body-weight shifting—the two approaches most favored by flight experimenters—could compensate for the effects Wrights' invention was, in fact, of wind shifts on such aircraft. Early Wright gliders continued to sideslip, despite wing- nothing more than a basic aero- warping, until the addition of a movable . nautic principle. Worse, he alleged that it had been discovered years invention—an idea that they called Not long afterward, the Wrights before the Wrights embarked on se- "wing-warping." received patents on wing-warping. rious aviation careers. Wing-warping was a novel flight- However, Curtiss soon began using It was a sensational charge, one control system. It entailed twisting the technique in his own , that did not die there. The claim the ends of wings in opposite direc- employing different mechanical haunted the brothers through a long tions at the same time. With it, the means. The Wrights sued, crying series of lawsuits waged at home Wrights' flyer managed to retain patent violation. Curtiss responded and abroad. Time and again, they balance in air, execute turns on that, while the brothers could patent were pressed to prove their pater- command, and thus stage, in 1903, their specific mechanical means of nity of the idea at the core of their the first powered flight. applying the wing-warping princi-

150 AIR FORCE Magazine / September 1989 This photo of the Wrights' second powered flyer, the II, taken at Simm Station on (now part of Wright- Patterson AFB) in Ohio, clearly shows the twist in its wings. The wing-warp and rudder controls were still connected, which caused serious control problems that would not be solved until 1905. pie, they could not patent the prin- Even earlier, in an 1899 letter that From their reading, the Wrights ciple itself, particularly since they Wilbur wrote to the Smithsonian In- said, they had learned that experi- hadn't discovered it. stitution seeking information about menters pursued one of two tracks. With the Wrights maintaining that flight, he had mentioned his habit of One group tried to build stable ma- they had made the discovery, and observing birds. chines that could be steered like Curtiss insisting they had not, reso- Did the Wright brothers really get autos. The other tried to compen- lution of the matter turned on the their idea of wing-warping from the sate for wind changes by shifting a question of when, where, and how birds? Perhaps. Years later, how- pilot's body weight in flight. The the Wrights first hit on the basic idea ever, Orville would discount the val- "drivers" found that their machines of wing-warping. ue of such observations. He stated could remain balanced only in calm that he could think of nothing origi- air. Their rivals found that "body From the Birds nal the brothers had learned in this English" alone was insufficient for The simplest answer provided by way. airborne control. the Wrights was that they had "Learning the secret of flight The Wrights decided to build a learned about it from the birds. from birds is a good deal like learn- hybrid—an unstable machine Wilbur Wright advanced this claim ing the secret of magic from a magi- equipped with mechanical means of as early as the spring of 1900, long cian," he explained. "After you control. The answer was a system to before the lawsuit, in his first letter know the trick and know what to duplicate the birds' twisting of their to Octave Chanute, a French-born look for, you see things that you did wingtips. glider enthusiast. not notice when you did not know Wilbur wrote: "My observation of exactly what to look for." An Accidental Solution the flight of buzzards leads me to For some, this raises the question After a false start, Wilbur hit on a believe that they regain their lateral of whether the Wrights learned "the solution by accident. A customer balance, when partly overturned by trick" from others. In his 1899 had come to the Wrights' a gust of wind, by a torsion of the Smithsonian letter, Wilbur men- shop to buy an inner tube. Wilbur tips of the wings. If the rear edge of tioned reading a work by Etienne pulled one from a pasteboard box. the right is twisted upward Jules Marey that described the ac- While the two chatted, Wilbur idly and the left downward the bird be- tion of birds' wings. Similar descrip- twisted the box in his hands. Sud- comes an animated windmill and in- tions of the flight of birds are found denly, he realized he was producing stantly begins to turn, a line from its in pamphlets provided by the the kind of torsion he wanted. head to its tail being the axis." Smithsonian and in books that it In 1898, the Wrights tried out the Wilbur added that he planned to suggested to the Wrights. concept in the double-decker kite build an apparatus that would add Understanding the birds' secret Wilbur described to Chanute the this torsion principle to a double- of control was one thing. Finding a following year. The kite proved the deck glider, one similar to the type practical means of applying that se- principle. Over the next three years, Chanute had used. Wilbur said that cret to a man-carrying flyer, how- they built a series of gliders using he already had tested the idea on a ever, was quite another. On this key the same wing-warping system. kite and was sufficiently encour- issue, the Wrights again claimed When the gliders tended to slew and aged to lay plans for a trial using a that they had worked out a solution sideslip, the Wrights added fixed full-size machine. independently. rear fins. When that failed to work, AIR FORCE Magazine / September 1989 151 they converted the fixed fins into a ignored the warning and, in 1909, Esnault-Pelterie's machine didn't movable rudder connected to the formed a company with Augustus work well, but others picked up on wing-warping control. Herring to produce machines for the idea of in their own air- In 1903, they built a flyable pow- sale. Their first was the Gold Bug, craft. Among these inventors was ered machine. Yet it and two subse- sold to the Aeronautic Society of Curtiss. quent machines continued to dis- New York. They built a second, the When the Wrights sued Curtiss, play control problems. It was not Golden Flyer, for Curtiss to fly in Chanute vowed to remain neutral, until 1905 that the Wrights separated the Gordon Bennett trophy race in but he fed the Wrights' opposition warping and rudder controls so each , France. On the eve of the its best arguments. In an August could move independently. Thus race, the Wrights filed formal patent 1909 letter to Aeronautics Maga- was born a machine with the basic suits against the Herring-Curtiss zine, Chanute claimed that the ingredients of a modern plane. Co., Glenn Curtiss, and the Aero- Wrights' suit would not only antag- Satisfied that they had perfected a nautic Society of New York. onize many, but might also "dis- practical craft, the Wrights stopped None of Curtiss's machines used close some prior patents which will flying for more than two and a half the Wrights' wing-warping system. invalidate their more important years. Instead, they had small, movable claims." Later, Chanute wrote the During part of the time, they wait- surfaces mounted between the ends editor again, giving specifics. He ed for approval of their patent. They of the upper and lower wings. As claimed that, after first making con- had applied in March 1903, nine one of these ailerons was raised, tact with the Wrights, he provided months before their historic first that on the opposite side automati- them with a copy of an 1897 patent flight. In May 1906, it was granted. cally lowered. The effect of ailerons granted Louis-Pierre Mouillard for Soon, the brothers were seeking was the same as that of wing-warp- a system that "clearly covers the customers; by the summer of 1908, ing. warping of wings." the Wrights were flying once more. Curtiss did not claim to have in- Chanute had carried on a lengthy By then, however, they did not vented ailerons. What's more, the correspondence with the French in- have the air to themselves. Their experimenter who did invent them ventor, giving him encouragement success had rekindled enthusiasm conceded that he had been inspired and financial support. When Mouil- among experimenters. The rival by the Wrights' success with wing- lard had little success with his con- machines varied in design, but the warping. Ironically, the man at the trol system and showed no interest successful ones shared a common heart of the business was in seeking a patent, Chanute himself feature: some means of changing none other than the Wright's old applied for a US patent on it in the trailing edges of the wings so friend and mentor, Octave Chanute. Mouillard's name and his own. It they would work in opposite direc- was granted in 1897, a few months tions. Chanute Talks before Mouillard died. Since Wilbur's first letter to Cha- Chanute said that he had told the Aileron Controversy nute, he and his brother had kept in Wrights they were free to use Mouil- The first such machine to arouse touch with the older man. Chanute lard's system because Mouillard the Wrights' concern was made by encouraged them to share their re- was dead and his heirs had made no Curtiss. A motorcyclist and engine sults with other experimenters. At claim to it. Years later, Orville said builder, Curtiss had joined the first, the Wrights did so. As they that he did not remember Chanute's Aerial Experiment Association. In neared success, however, they grew offer and that, in any event, the January 1908, the Wrights gave more guarded about the information Wrights had not been interested, AEA information about their con- they disclosed. having already developed their own trol system on the understanding It was one thing for the Wrights to wing-warping controls. that it would be used for experimen- keep their mouths shut, but re- By October 1909, Chanute was tal work, not for production of com- straining the voluble Chanute was talking not only to the press but to mercial machines. quite another matter. In April 1903, the rival legal camp, suggesting The association built three months before the Wrights' first other impediments to the Wrights' planes. The last, known as the June flight, Chanute gave a brief descrip- claims. In a formal legal statement Bug, was designed by Curtiss. The tion of their wing-warping idea in a on the origins of wing-warping, he Wrights were miffed when Curtiss speech before France's Aero Club. wrote: "The bare idea of warping used it to win a trophy from Scien- The talk was covered by aviation and twisting the wings is old, but tific American Magazine for the journals, and the next year, French there are several ways of accom- first officially recorded American experimenter Robert Esnault-Pelterie plishing it." He named others be- flight of more than a kilometer. The attempted to copy the . sides Mouillard who had described Wrights themselves had covered Deciding that twisting the wings the principle or actually developed greater distances, at least since would weaken its structure, he de- systems for using it. 1905, but no official observers had signed a system in which the wings been present. would remain rigid and smaller, sep- The Last Straw Soon, Orville was warning Cur- arate surfaces would move. He The New York World quoted Cha- tiss that the June Bug's use of mov- called them "horizontal ," nute in a series of articles question- able wing surfaces was covered by but they soon became known as ai- ing the Wrights' claim. The paper the Wrights' patents. He invited lerons (from the French word for suggested that they had gotten most Curtiss to seek a license. Curtiss wing, aile). of their ideas from Chanute himself. 152 AIR FORCE Magazine / September 1989 For the Wrights, that was the last suggestions can hope to link their A Partial Victory straw. Wilbur fired off a scorching names with the honor of its discov- By then, a New York circuit court letter to Chanute, reminding him ery." had ruled that the Mouillard sys- that Chanute had assured them as Chanute aired a long-festering tem, which turned down one wing- early as 1901 that their system was grievance. He said that he resented tip at a time, was meant only to turn an original. the impression the Wrights had the airplane. If Mouillard had tried In his reply, Chanute conceded given that he had thrust himself on to use it to maintain balance, the that the Wrights' system was origi- them and had been of no real help in court said, it would have disturbed nal, but added that "it does not fol- their work. the equilibrium rather than restored low that it covers the general princi- Wilbur's answer was equally bit- it. In any case, the court said, it did ple of warping or twisting wings; the ter. If Chanute resented being given not bear on the Wrights' claim. proposals for doing this being an- too little credit for his contribution, The victory was partial. It did not cient." he said, then the brothers resented involve the case against Curtiss, but Chanute said that he thought he his giving the impression that they rather an injunction against Louis had called the Wrights' attention to were no more than his pupils. Paulhan, a French flyer whom the Mouillard's system. "If the courts "As to inordinate desire for Wrights had accused of infringing will decide that the purpose and re- wealth," Wilbur concluded, "you their patents by bringing European sults were entirely different and that are the only person acquainted with machines into the US for exhibi- you were the first to conceive the us who has ever made such an accu- tions. Within a year, however, the twisting of the wings," he said, "so sation. We believed that the phys- Wrights had won favorable rulings much the better for you, but my ical and financial risks which we in French courts and were begin- judgment is that you will be re- took, and the value of the service to ning to work out royalty arrange- stricted to the particular method by the world, justified sufficient com- ments with European plane makers. which you do it." pensation to enable us to live mod- "The French decision," Orville Chanute added, "I am afraid, my estly with enough surplus income to wrote to a friend, "virtually clinches friend, that your usually sound judg- permit the devotion of our future our case in the American courts." ment has been warped by the desire time to scientific experimenting in- His prediction was premature. for great wealth." stead of business." The Curtiss case dragged on. In

Lt. Harold Geiger in a Curtiss Pusher S. C. #8 airplane at San Diego, Calif., in 1913. Curtiss planes made use of wing-warping but employed independent ailerons for control. The Wrights' patent suits against Glenn Curtiss dragged on for eight years, outlasting their ownership of the Wright Co. and its patents and outlasting Wilbur himself. This last barb doubtless was cal- The rift lasted for months. Final- 1910, the Wrights offered to end it if culated to draw blood. The Wrights' ly, Wilbur wrote a conciliatory note Curtiss would take out a license un- greatest booster was accusing them suggesting they mend their friend- der their patents and settle for past of greed. In his first letter to Cha- ship and work out a statement de- infringements. Curtiss demurred, nute, Wilbur had said, "I make no scribing Chanute's contribution. and the Wrights dropped the offer. secret of my plans for the reason Chanute said that he too was eager By late 1911, they had won injunc- that I believe no financial profit will to resume good relations. They nev- tions against Curtiss, but no final accrue to the inventor of the first er worked out the statement, how- judgment. flying machine, and that only those ever, and Chanute died that Novem- Meanwhile, the Wrights suffered willing to give as well as to receive ber at seventy-eight. a setback in the German courts. AIR FORCE Magazine / September 1989 155 Curtiss took the machine to his fac- tory at Hammondsport, N. Y., and not only restored it but rebuilt it. He strengthened the wings, changed their curvature, added a new control system, and substituted a Curtiss engine for Langley's original. The aerodrome collapsed again on its first trial, but Curtiss continued to change it until he was able to coax it into the air for a few short . Without disclosing the craft's modifications, the Smithsonian an- nounced that Langley's machine had flown. The aerodrome was re- turned to its original condition and displayed at the museum with a sign describing it as "the first man-carry- ing aeroplane in the history of the world capable of sustained free flight." That made Orville so angry that he sent the original Wright flyer to a British museum, where it re- In an attempt to discredit the Wrights' claim by proving that 's aircraft mained for years. He agreed to could actually have flown in 1903, Curtiss rebuilt Langley's "aerodrome"—with Improvements. Here, Langley's original is fished from the Potomac River after an bring it back only after the Smith- unsuccessful attempt. In both of its 1903 flight tests, its wings collapsed. sonian removed the sign and admit- ted how much the aerodrome had German law held that disclosure of modifying his control system so that been altered to make it fly. an invention before application for a each aileron could be worked inde- Whether the aerodrome hoax patent invalidates the patent. Again, pendently. Orville brought another would have worked for or against it was Chanute who had created the suit, and the whole process began Curtiss in court remains moot. Or- problem. When the court learned of anew. ville's new suit against Curtiss never his description of the Wrights' wing- came to ajudgment. In 1915, he sold warping to the French Aero Club, it Restoring Langley's Machine the Wright Co. and patents to New ruled that it was enough to compro- Curtiss now looked for a new way York capitalists. The new company mise their claim. German patents to discredit the Wrights' claim. A continued the suit, but Curtiss man- had not been sought until March possibility, he decided, would be to aged to delay until 1917, when a 1904. prove that Samuel Langley's "aero- cross-licensing agreement eased all Back in the US, Curtiss appealed drome," which did not use wing- patent restrictions to speed wartime the injunction and, by posting a warping, could fly. That machine production. bond, was able to continue to build was designed by Langley while he The Wrights had not made a for- planes. By May 1912, Wilbur was was Secretary to the Smithsonian tune, but Orville did have enough to seriously ill with typhoid fever. The Institution. It had been tested live modestly and devote his time to long legal ordeal weighed heavily on twice, a few weeks before the experimenting. He became em- him. In a letter to a friend, he com- Wrights' successful flight of 1903. broiled in other suits, most claiming plained that competitors already Both times, its wings collapsed be- that someone else had flown first or were selling machines at prices be- fore it was airborne. Langley, ridi- had developed a control system that low those the Wrights were asking. culed for his failure, died a few predated the Wrights'. None suc- If the case dragged on much longer, years later. He had been able to fly ceeded. he said, others would find new ways successful steam-driven models as Even today, however, writers of evading their claims, even in the early as 1896, however, and support- plow the old ground, seeking proof event of a favorable judgment. ers still believed that his full-sized that the Wrights really weren't first. Wilbur died a few weeks later. Or- aerodrome would have worked. The Wrights may have borrowed ville was convinced that the ordeal Curtiss approached the Smith- more than they liked to admit and of the long court battles had helped sonian with the idea of restoring the may have given Chanute and others to kill him. Langley machine and attempting a less credit than they deserved. The Orville continued the patent fight flight. The Institution, eager to re- fact remains that they were the first alone and, for a time, seemed to be deem Langley's reputation, agreed. to put it all together and fly. • winning. In January 1914, a federal appeals court in New York rendered A World War II B-24 bombardier, Bruce D. Callander was recalled to active judgment in the Curtiss case, up- duty during the Korean War. Between tours of active duty, he earned a B.A. in holding the Wright patents. But, journalism at the University of Michigan. In 1952, he joined Air Force Times, with his business threatened, Cur- becoming Editor in 1972. His most recent article for AIR FORCE Magazine was tiss tried to skirt the court order by "Enlisted Pilots" in the June '89 issue.

156 AIR FORCE Magazine / September 1989