Two physical impossibilities reported by Wilbur Wright to Octave Chanute:
1) "While the new machine lifts at a speed of about 23 miles, it is only after the speed reaches 27 or 28 miles that the resistance falls below the thrust. ", Wilbur Wright, August 8, 1904
The plane lifted at 23 mph having the Thrust smaller than the Drag all the time (no catapult was used)!
2) "We find that the greatest speed over the ground is attained in the flights against the stronger breezes.", Wilbur Wright, August 28, 1904
The reality is that a headwind slows down a plane and this is exactly the opposite of what W. Wright claimed he had measured.
Only one conclusion can be drawn, the two letters describe imaginary flights and Wilbur Wright was simply bluffing (unfortunately for him using misconceptions, wrong beliefs, not good physics and math) with the intention to convince Octave Chanute and others that he had really flown.
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Letter 1: Fragment from a letter addressed by Wilbur Wright to Octave Chanute, on August 8, 1904: "
One of the Saturday flights reached 600 ft. ... We have found great difficulty in getting sufficient initial velocity to get real starts. While the new machine lifts at a speed of about 23 miles, it is only after the speed reaches 27 or 28 miles that the resistance falls below the thrust. We have found it practically impossible to reach a higher speed than about 24 miles on a track of available length, and as the winds are mostly very light, and full of lulls in which the speed falls to almost nothing, we often find the relative velocity below the limit and are unable to proceed. ... It is evident that we will have to build a starting device that will render us independent of wind." Source: Page 52 of Octave Chanute Papers: Special Correspondence--Wright Brothers, 1904 | Library of Congress
Letter 2: Fragment from the letter written by Wilbur Wright to Octave Chanute on August 28, 1904: "
Dayton, Ohio, August 28, 1904. Dear Mr Chanute ... ... Since the first of August we have made twenty five starts with the #2 Flyer. The longest flights were 1432 ft., 1304 ft, 1296, ft. and 1260 ft. These are about as long as we can readily make on over present grounds without circling. We find that the greatest speed over the ground is attained in the flights against the stronger breezes. We find that our speed at startup is about 29 or 30 ft per second, the last 60 ft of track being covered in from 2 to 2 1/4 seconds. The acceleration toward the end being very little. When the wind averages much below 10 ft per second it is very difficult to maintain flight, because the variations of the wind are such as to reduce the relative speed so low at times that the resistance becomes greater than the thrust of the screws. Under such circumstances the best of management will not insure a long flight, and at the best the speed accelerates very slowly. In one flight of 39 1/4 seconds the average speed over the ground was only 33 ft per second, a velocity only about 3 ft per second greater than that at startup. The wind averaged 12 ft per second. In a flight against a wind averaging 17 ft per second, the average speed over the ground was 42 ft per second, an average relative velocity of 59 ft per second and an indicated maximum velocity of 70 ft per second. We think the machine when in full flight will maintain an average relative speed of at least 45 miles an hour. This is rather more than we care for at present. Our starting apparatus is approaching completion and then we will be ready to start in calms and practice circling. Yours truly Wilbur Wright." Source: Page 55 of Octave Chanute Papers: Special Correspondence--Wright Brothers, 1904 | Library of Congress
Attention: The flights Wilbur Wright talked about in his August 8 and 28 letters to Octave Chanute (see were done close to Dayton Ohio, at a few meters above a flat pasture. No catapult was used.
Wilbur Wright did not know that the airspeed of a plane is independent of the wind-speed
The elder of the two brothers had a logbook for keeping track of the lies transmitted with the help of his letters to Octave Chanute and others. In this notebook, at page 8, with flight data about alleged flights performed on August 13, 1904, Wilbur wrote the same figures as in the August 28, 1904, text addressed to O. Chanute but in a more organised manner.
This is what he recorded and calculated (see the attached picture):
Flight 28 (second flight of August 13, 1904)
Av wind = 12.2 fps
Speed = 33.2 fps
Rel. Speed = 45.4 fps
Flight 29 (third flight of August 13, 1904)
Av wind = 17 fps
Speed = 42 fps
Rel. Speed = 59 fps
Flight 30 (fourth flight of August 13, 1904)
Av wind = 14 fps
Speed = 35 fps
Rel. Speed = 49 fps
Remark: The wind-speed was measured with a ground anemometer and the ground-speed of the plane was calculated from the flight time and the distance traveled across the pasture.
As you can see, for each of the three flights, W. Wright correctly applied the formula:
Ground Speed = Relative Speed - Wind Speed
However, he missed the fact that the relative speed (the airspeed) must be the same for all flights because a plane moving in a block of air traveling in a certain direction has no means to know that the air is moving. The plane always sees itself as traveling in calm air (no wind).
Relative Speed= ct (This is what W. Wright did not know when he did the math for his imaginary flights of August 13, 1908)
If you look at the three trials mentioned above you will see that instead of going down, with an increase of the headwind-speed, the ground-speed was also growing!!
Source:
Page 6 of Diaries and Notebooks: 1904-1905, Wilbur Wright
(The 1904-1905 Notebook of Wilbur Wright)
Definitely what Wilbur wrote in his logbook and in the August 28, 1904, letter to O. Chanute is a proven fraud. He simply could not have obtained three different air-speeds for three distinct headwind-speeds had he and his brother really flown a powered plane.