After the Langley machine had been restored as nearly as possible to its original state, it was placed on exhibition by the Smithsonian. Soon afterward it bore a label that falsely proclaimed it to be “the first man-carrying aeroplane in the history of the world capable of sustained free flight.”
But neither in connection with the exhibit of the Langley plane nor in any report of the Smithsonian Institution was there any hint of the fundamental changes made at Hammondsport, without which the plane could not possibly have carried its weight. One of these changes had to do with the supporting posts on the wings. Professor Langley had not known—indeed, no one knew until the Wrights’ wind-tunnel experiments established the facts—where the center of the air pressure would be on a curved surface, and consequently he had failed to place his wing-trussing posts where they were most needed. In the attempts to fly the machine over the Potomac, in 1903, the wing that bore the greater part of the weight had each time collapsed at the moment the apparatus left the starting platform. (Lacking the knowledge about curved surfaces that later was available, those in charge of the 1903 trials had blamed the trouble on the launching apparatus.) At the Hammondsport tests, the trussing posts were moved thirty inches rearward. This brought the guy posts almost exactly in the same plane with the center of pressure on the wings and thus eliminated the backward pull that had wrecked the machine in the 1903 tests.
Three fundamental changes were made in the design of the wings themselves: (1) The camber was greatly changed; (2) the shape of the leading edge was entirely different; (3) the aspect ratio—the ratio of span to chord—was increased. These three features are the most important characteristics in determining the efficiency of a wing. The change of the camber of itself may increase the efficiency of a wing by thirty per cent. And not only were the wings changed as to design, but they were strengthened by various means of reinforcing and trussing not used by Langley. Even the cloth on the wings was improved by varnishing, to make the wings more efficient. Langley had not used varnish on the cloth.
Numerous changes were made in other parts of the machine. The large fixed vertical keel surface, situated below the main frame in 1903, was entirely omitted in 1914. This omission improved the machine’s stability. A different kind of rudder was used. The position of the “Pénaud tail” used by Langley was raised about ten inches to increase the stability of the machine, and was connected to a modern steering post, to give better control. The forward corners of the original Langley propellers were cut off in the manner of the early Wright propellers to increase their efficiency. As the system of control Langley had used was not adequate, the aileron system, covered by Wright patents, a system unknown to Langley, was added.
How did all these changes become known? Orville Wright called attention to them in an affidavit in 1915 in the Wright-Curtiss lawsuit. One way to learn most of the facts is astonishingly simple. All that is necessary to any observer who knows what to look for is to make careful comparisons of the Smithsonian photographs of the original Langley machine with Smithsonian photographs of the machine tested at Hammondsport.
It was learned, too, that even the engine used by Langley was changed in several respects. A modern type carburetor, a new intake manifold, a magneto ignition, and a modern radiator were installed.
Though all these changes and many others were made in the machine at Hammondsport, the Smithsonian published only a few of them—the less important. It did not tell of the fundamental changes. And the Institution made statements that, by implication, practically amounted to a denial that any changes of importance had been made.
By omitting from its published reports at the time and for many years afterward, the facts about the changes in the Langley machine, the Smithsonian Institution succeeded in deluding the public. If the stories about these fake tests had been issued by Curtiss, who conducted them, or by an organization less well known than the Smithsonian, they might not have been taken seriously. But when false and misleading announcements were backed by the prestige of a famous scientific institution, it was possible to have the fraudulent character of the experiments pass generally unsuspected. When the reports of Secretary Walcott of the Smithsonian Institution said the “original” Langley machine had made “flights,” and when the report of the National Museum said the Langley machine had been flown “without modification,” such statements, untrue though they were, naturally carried weight. Indeed, the misstatements were so widely accepted as fact that they began to find their way into school text-books and into encyclopedias.
Griffith Brewer, the English aeronaut, delivered a lecture before the Royal Aeronautical Society in London, in October, 1921, and exposed the fraudulent nature of the Hammondsport tests. In this lecture he mentioned many of the vital changes made in the Langley plane before any attempt was made to fly it. Dr. Walcott made a statement in reply to Brewer. Up to this time Orville Wright had thought that Walcott could have been ignorant of those changes; but after reading the Walcott statement he was convinced that there was nothing accidental or unintentional about the misstatements published by the Smithsonian regarding the tests at Hammondsport.
While the Kitty Hawk plane rested in its storage place, subject to possible fire hazards, officials of the Science Museum at South Kensington, London, England, had made requests to have the machine for exhibition there. After Orville Wright became convinced that none of the Members or Regents of the Smithsonian Institution or any other influential persons were enough interested in establishing the facts in controversy to go to the trouble of making an investigation, he reluctantly decided, in 1923, to accede to the requests from London. In reply to letters deploring this decision, he has expressed his reasons as follows: