The Airplane - Jay Spenser [75]
Competing to be first across the English Channel in 1909, Hubert Latham flew an Antoinette equipped with ailerons, whereas Louis Blériot used wing warping on his Model XI. Alberto Santos-Dumont’s graceful Demoiselle employed wing warping, whereas Farman used ailerons (the latter technology would soon win out because the former works only on thin, flexible wings and requires drag-inducing wires).
The only European who did not learn from the Wrights was Gabriel Voisin. He willfully resisted out of Gallic pique. Consequently, of the many machines flying at the Reims air meet in August 1909, his alone lacked any provision for roll control.
If the Wrights had lessons to teach others about roll control, it was the other way around when it came to pitch. Orville belatedly acknowledged as much in a letter he wrote to Wilbur in September 1909. “The difficulty in handling our machine is due to the [horizontal] rudder [i.e., elevator] being in front, which makes it hard to keep on a level course,” he wrote. “I do not think it is necessary to lengthen the machine, but to simply put the [horizontal] rudder behind instead of before.”16
The result was the Wright Model B of 1910, a revised Model A with its elevator at the rear. America’s first production airplane, the Model B was also the first flyer with wheels. These were merely affixed to the skids, however, and not a new landing gear. The Model B retained the Wrights’ front blinkers, but they were now mounted on the front skid struts since there was no forward elevator. By then, however, the rest of the world had pretty much agreed that the vertical stabilizer should be at the rear with the rudder.
In short, the world had passed the Wrights by. For whatever reason—be it an excessive investment in the past or too much energy expended on their patent disputes with Glenn Curtiss and the Europeans—they were now far behind on the configuration front.
Europe also had lessons to teach the Wrights about stability. The winning formula for aviation actually turned out to be a combination of the Wrights’ three-axis control concept and Europe’s pursuit of inherent stability. This synthesis made possible airplanes that were reasonably safe, stable, and forgiving, as well as fully controllable.
Only in the 1970s would aviation return to the Wrights’ notion of inherent instability as the route to greater maneuverability. Starting with jet fighters such as the General Dynamics (today Lockheed Martin) F-16 Fighting Falcon, modern fighters offer the best of both worlds. Designed statically unstable for extreme maneuverability, they nevertheless present their pilots with stable, forgiving handling characteristics thanks to computerized fly-by-wire flight control systems that do the hard work. So inherently unstable are these astonishing machines that they could not be flown without the aid of computers.
Jetliners too have a noteworthy controllability feature not seen in the early days of aviation. These are the spoilers atop the wings. Hinged at front, they can rise fractionally into the slipstream in flight. Depending on how they are employed, spoilers can do several things. When used differentially so that only the spoilers on one side rise into the slipstream, they tilt the airplane into a bank. Like ailerons, therefore, they provide roll control (spoiler use is in fact preferable in some instances because it avoids the adverse yaw associated with ailerons).
When used symmetrically, spoilers either slow down the jetliner without changing its altitude and attitude, or allow it to descend at a high rate without excessive speed buildup. It all depends on how the flight crew uses the spoiler application. They can also be actuated by the airplane’s autoflight system when on autopilot.
Because of their placement on the wings, a jetliner’s spoilers are readily visible to the passengers and can be fun to watch. They scarcely rise when used for roll control but are more evident when employed for killing lift. The laminar flow over the wing becomes locally turbulent when lift