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1908-06-13, Orville and Wilbur Wright, “Our Aeroplane Tests at Kitty Hawk”, Scientific American, New York, Munn & Co., June 13, 1908, Vol. XCVIII, No. 24, p. 423.

 

OUR AEROPLANE TESTS AT KITTY HAWK.

BY ORVILLE AND WILBUR WRIGHT.

The spring of 1908 found us with contracts on hand, the conditions of which required performance not entirely met by our flights in 1905. The best flight of that year, on October 5, covered a distance of a little over 24 miles, at a speed of 38 miles an hour, with only one person on board. The contracts call for a machine with a speed of 40 miles an hour, and capable of carrying two men and fuel supplies sufficient for a flight of 125 miles. Our recent experiments were undertaken with a view of testing our flyer in these particulars, and to enable us to become familiar with the use of the controlling levers as arranged in our latest machines.

After tedious delays in repairing our old camp at Kill Devil Hills, near Kitty Hawk, N. C., we were ready for experiments early in May. We used the same machine with which we made flights near Dayton, Ohio, in 1905; but several modifications were instituted to allow the operator to assume a sitting position, and to provide a seat for a passenger. These changes necessitated an entirely new arrangement of the controlling levers. Two of them were given motions so different from those used in 1905 that their operation had to be completely relearned.

We preferred to make the first flights, with the new arrangement of controlling levers, in calm air; but our few weeks’ stay had convinced us that in the spring time we could not expect any practice at that place in winds of less than 8 to 10 miles an hour, and that the greater part of our experiments must be made in winds of 15 to 20 miles.

The engine used in 1905 was replaced by a motor of a later model, one of which was exhibited at the New York Aero Club show in 1906. The cylinders are four in number, water cooled, of 4Ľ-inch bore and 4-inch stroke. An erroneous statement, that the motor was of French manufacture, has appeared in some papers. This is, no doubt, due to the fact that we are having duplicates of this motor built by a well-known Paris firm, for use in European countries.

The longer flights this year were measured by a Richard anemometer attached to the machine in the same manner as in 1905. Except in the first few flights, made over regular courses, it was found impracticable to secure accurate measurements in any other way. These records show the distances traveled through the air. The measurements of the velocity of the wind were made at a height of six feet from the ground at the starting point, and were usually taken during the time the machine was in flight.

The first flight was made on the 6th of May, in a wind varying from 8 to 12 miles an hour. After covering a distance of 1,008 feet measured over the ground, the operator brought the machine down to avoid passing over a patch of ground covered with ragged stumps of trees.

In the morning of May 8 several short flights were made in winds of 9 to 18 miles an hour. In the afternoon the machine flew 956 feet in 31 seconds, against a wind of a little over 20 miles an hour; and later, a distance of 2,186 feet in 59˝ seconds, against a wind of 16 miles. These distances were measured over the ground.

On May 11 the Richard anemometer was attached to the machine. From this time on the flights were not over definite courses, and the distances traveled were measured by this instrument. Three flights were made on this day in winds varying from 6 to 9 miles. The distances were: 0.78 mile, 1.80 miles, and 1.55 miles.

On May 13 four flights were made. The anemometer on the machine registered a distance of 0.60 mile in the first; 1.85 miles in the second; no distance measurement in the third — time, 2 minutes and 40 seconds; and 2.40 miles in the fourth. The velocity of the wind was 16 to 18 miles an hour.

On May 14 Mr. C. W. Furnas, of Dayton, Ohio, who was assisting in the experiments, was taken as a passenger. In the first trial, a turn was not commenced soon enough, and to avoid a sand hill, toward which the start was made, the power was shut off. The second flight, with passenger on board, was in a wind of 18 to 19 miles an hour. The anemometer recorded a distance traveled through the air of a little over 4 kilometers (2.50 miles) in 3 minutes and 40 seconds. The last flight was made with operator only on board. After a flight of 7 minutes and 29 seconds, while busied in making a turn, the operator inadvertently moved the fore-and-aft controlling lever. The machine plunged into the ground, while traveling with the wind, at a speed of approximately 55 miles an hour. The anemometer showed a distance of a little over 8 kilometers (5 miles).

The frame supporting the front rudder was broken; the central section of the upper main bearing surface was broken and torn; but beyond this, the main surfaces and rudders received but slight damage. The motor, radiators, and machinery came through uninjured. Repairs could have been made in a week’s time, but the time allowed for these experiments having elapsed, we were compelled to close experiments for the present.

These flights were witnessed by the men of the Kill Devil life-saving station, to whom we were indebted for much assistance, by a number of newspaper men, and by some other persons who were hunting and fishing in the vicinity.

The machine showed a speed of nearly 41 miles an hour with two men on board, and a little over 44 miles with one man. The control was very satisfactory in winds of 15 to 20 miles an hour, and there was no distinguishable difference in control when traveling with, against, or across the wind.

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