Omega G. East

“ When a model flies, it does not necessarily follow that a full-size machine of the same design will also fly. As boys Wilbur and Orville had built model Pénaud helicopters that flew, but even the Wrights could not later have built a successful man-carrying machine by merely following Pénaud’s same general design. The difficulty is—as early experimenters with model machines unhappily discovered—that when the linear measurement of a model is doubled it needs about eight times the power to make it fly. ”

“ Wilbur and Orville had misread the weather charts they had studied when choosing Kitty Hawk as the location for their experiments. The charts had listed monthly averages, while the day-by-day weather proved to be less than ideal. On some days tests could not be made because of a dead calm; other days the wind blew too strong—up to 45 miles an hour. Orville wrote about the strong winds that blew:
A little excitement once in a while is not undesirable, but every night, especially when you are so sleepy, it becomes a little monotonous.... ”

“ They knew that they must learn how properly to build and control a glider before attempting to add a motor. “When once a machine is under proper control under all conditions,” Wilbur wrote his father from camp, “the motor problem will be quickly solved. A failure of motor will then mean simply a slow descent & safe landing instead of a disastrous fall.” They looked forward to the next slack season in the bicycle business so that they might resume experiments with a new glider. ”

“ The first successful flight ended with a sudden dart to the ground after having flown 120 feet from the take-off point in 12 seconds time at a groundspeed of 6.8 miles an hour and an airspeed of 30 miles an hour. In the words of Orville Wright:
This flight lasted only 12 seconds, but it was nevertheless the first in the history of the world in which a machine carrying a man had raised itself by its own power into the air in full flight, had sailed forward without reduction of speed, and had finally landed at a point as high as that from which it started. ”

“ Why Kitty Hawk?
Wilbur and Orville now proposed to build a full-size, man-carrying glider on which to test their method of control. Highly enthusiastic with the idea of gliding as a sport, they started thinking of a place for testing it. To get practice in operating the glider, they would first fly it as a kite before making gliding flights. For kite flying, steady winds and flat, open country were needed; for the gliding, a sandy area for soft landings and sandhill slopes free of 14 trees and shrubs for low-level flights. ”

“ Occasionally in free flight, the warping of the wings to increase the angle of attack to recover lateral balance did not produce the desired result. The wing having the greater angle sometimes lost speed as it lifted, compared with the opposite wing having a lesser angle. The brothers then realized that the greater angle of the wing on one side gave more resistance to forward motion and reduced the relative speed of that wing. This decrease in speed more than counterbalanced the effect of the larger angle of the wing in producing lift. ”

“ A longtime encouraging friend and adviser to the Wrights, Chanute made an exhaustive study of the history of aeronautics.
Problems of Flight
A pioneer experimenter once said that “it is easy to invent a flying machine; it is more difficult to build one—but to make one fly is everything.” As Lilienthal had seen, the Wrights also saw that, if ever they were to make progress in solving the problems of flight, they had not only to study them theoretically, but also to get up into the air in gliders and test their theories by actual practice. ”

“ Commercial companies were formed in France and Germany to manufacture Wright planes before the Wright Company was organized in the United States with Wilbur as president and Orville vice president. In financial affairs the Wrights were remarkably shrewd—a match for American and European businessmen. They grew wealthy as well as famous, but they were not happy as businessmen and looked forward to the time when they could retire to devote themselves again to scientific research. ”

“ Even though the Wrights had only brief spells of favorable weather for practice, they learned much from their experiments. They were pleased with the efficiency of wing-warping to obtain lateral balance, and the horizontal rudder for fore-and-aft control worked better than they had expected. Though Wilbur and Orville believed that fore-and-aft balance and lateral balance were equally important, they were gratified that fore-and-aft balance was so easily attained. They made careful measurements of lift, drag, and angle of attack. The main defect of the glider was its inadequate lifting power. ”

“ Home again in Dayton, the Wrights were ready to carry out plans begun in camp at Kill Devil Hills for a powered machine. They invited bids for a gasoline engine which would develop 8 to 9 horsepower, weigh no more than 180 pounds or an average of 20 pounds per horsepower, and be free of vibrations. None of the manufacturers to whom they wrote was able to supply them with a motor light enough to meet these specifications. The Wrights therefore designed and built their own motor, with their mechanic, Charles E. Taylor, giving them enthusiastic help in the construction. ”

“ Many among those who realized the obstacles to heavier-than-air flight in a powered machine believed it was as impossible as perpetual motion.
Wilbur and Orville acknowledged Otto Lilienthal, a famous German pioneer in aviation, as their greatest inspiration. Recognized as the father of gliding, Lilienthal made hundreds of glides with various apparatuses employing birdlike wings. First to explain scientifically why curved surfaces in a flying machine are superior to flat surfaces, Lilienthal’s work on wing surfaces and air pressure proved valuable to the Wrights. ”

“ We usually owned all our toys in common, talked over our thoughts and aspirations so that nearly everything that was done in our lives has been the result of conversations, suggestions and discussions between us. ”

“ The Wrights first flew the glider in the open as a kite. They held it with two ropes and operated the balancing system by cords 17 from the ground. The first day’s experiments were attempted with a man on board, using a derrick erected on a hill just south of their camp. The glider was not flown from the derrick again at Kitty Hawk after the first day’s tests. On days when the wind was too light to support a man on the glider, they used chain for ballast or flew the machine as a kite in the open without ballast. ”

“ Although important strides had been made toward solving the problem of control, Wilbur and Orville lacked opportunity for sufficient practice since they did not get much time in the air. There still remained much for them to learn before solving the major problems of how to (1) design wings properly, (2) control the aircraft in flight, and (3) provide power, in order to build and fly a powered machine. ”

“ The wind-tunnel experiments concluded in December 1901 made it possible for the Wrights to abandon the trial-and-error method of construction that had gone into their 1900 and 1901 gliders and to solve the basic problem of the correct design for lifting wings. Now they were able to devote their time to the two other major problems that had to be solved before human flight could be accomplished: a system for obtaining full control in the air, and the addition of an engine and propellers to the aircraft. ”

“ Only a few of the general public could distinguish between a heavier-than-air powered flying machine and a lighter-than-air gas bag equipped with propellers. Few knew that the problem of powered flight was not to fill a balloon with gas or hot air and float in it, or to glide in a complicated kite against air currents. ”

“ The visitor center represents the focal point in the interpretation of the area. In addition to an extensive series of modern museum exhibits telling the story of the memorial, the center also houses an information desk, where literature is available, and the administrative offices of the memorial. From the exhibition rooms, there is a sweeping panoramic view of the reconstructed 61 Wright brothers’ 1903 camp, the first flight grounds where markers designate the take-off and landing points of the first flights, and the Wright memorial shaft atop Kill Devil Hill. ”

“ When assembled, the new glider had a wingspan of 22 feet. It weighed 98 pounds, nearly double the weight of the earlier glider. To give it greater lifting power, the glider had a total lifting area of 290 square feet, considerably larger than the 165-foot wing area of the previous glider. The 1901 glider was a much larger machine than anyone had ever dared try to fly. It had the same system of control and general design as the first one. The Wrights increased the camber in this glider, from 1 in 22 to 1 in 12 to conform to the shape prescribed by Lilienthal’s tables of air pressure. ”

“ The highest engine speed measured developed 15.76 horsepower at 1,200 revolutions per minute in the first 15 seconds after starting the cold motor. After several minutes’ run 35 the number of revolutions dropped rapidly to 1,090 per minute, developing 11.81 brake horsepower. Even so, the Wrights were pleasantly surprised since they had not counted on more than 8 horsepower capable of driving a machine weighing only about 625 pounds. Having a motor with a power output of about 12 horsepower instead of 8, the Wrights could build the machine to have a larger total weight than 625 pounds. ”

“ Drag—A resistant force exerted in a direction opposite to the direction of motion and parallel to the relative gas or air Stream.
Dynamic lift—The lift given an airplane by the aerodynamic force produced from an adequately designed airfoil.
Glider—A fixed-wing aircraft having no power plant and constructed so as to glide and soar.
Gliding—The art, science, and activity of moving through the air in a glider.
Heavier-than-air aircraft—Any aircraft weighing more than the air it displaces. ”

“ Since the dawn of history the idea of human flight has intrigued mankind. As the influence of the Wrights’ achievements will last far into the future, so will the contributions of aeronautical pioneers 6 who probed the mysteries of flight before Wilbur and Orville solved the problem. ”

“ Disappointed by the relatively poor results achieved at Kitty Hawk with their 1901 glider, in the construction of which they had relied on Lilienthal’s and other published tables of air pressures, the Wrights decided to start again from scratch by conducting laboratory tests of their own and by evolving their own air pressure tables from measurements made with model airfoils (miniature wing surfaces) using a simple but effective homemade wind tunnel. ”

“ The truck, with the machine thereon, facing downhill, was fastened with a wire to the end of the starting track, so that it could not start until released by the pilot. The engine was started to make sure it was in proper condition. Two small boys, with a dog, who had come with the lifesavers, “made a hurried departure over the hill for home on hearing the engine start.” Each brother was eager for the chance to make the first trial, so a coin was tossed to determine which of them it should be; Wilbur won. ”

“ At 10:35 a.m., Orville lay prone on the lower wing with hips in the cradle that operated the control mechanisms. He released the restraining wire and the machine started down the 60-foot track, traveling slowly into the headwind at about 7 or 8 miles an hour—so slow that Wilbur was able to run alongside holding the right wing to balance the machine on the track. After a run of 40 feet on the track, the machine took off. When the airplane had risen about 2 feet above ground, Daniels snapped the famous photograph of the conquest of the air. ”

“ Errors can be guarded against only by repeating a message back to the sending station for comparison, and the Company will not hold itself liable for errors or delays in transmission or delivery of Unrepeated Messages, beyond the amount of tolls paid thereon, nor in any case where the claim is not presented in writing within sixty days after the message is filed with the Company for transmission. ”

“ The four successful flights made on December 17 were short because the Wrights, not desiring to fly a new machine at much height in strong winds, sometimes found it impossible to correct the up-and-down motion of the airplane before it struck the ground. Wilbur remarked:
Those who understand the real significance of the conditions under which we worked will be surprised rather at the length than the shortness of the flights made with an unfamiliar machine after less than one 51 minute’s practice. ”

“ Wind tunnel—A chamber through which air is forced at controlled velocities, up to several thousand miles an hour, and in which airfoils, airplanes, missiles, scale models of airplanes, or other objects are mounted in order to observe and study the airflow about such objects, as well as the aerodynamic effects upon them. ”

“ None of the early experimenters attained sufficient knowledge of the aerodynamic principles involved to be able to design a successful powered machine capable of free, controlled, and sustained flight. ”

“ The Wrights’ hometown of Dayton and its environs were not suitable for extensive glider trials. But because of their business demands, they wanted a site fairly close at hand.
On May 13, 1900, Wilbur wrote his first letter to Chanute asking advice on a suitable location to test a glider. In this letter to the man who became their friend, mentor, and most important correspondent, Wilbur stated:
For some years I have been afflicted with the belief that flight is possible to man. ”