The Wrong Wright Story 2
Peter Jakab's Visions of a Flying Machine
Part II of a critique by Joe Bullmer
Introduction to Part II
The previous article in truthinaviationhistory discussed the first four chapters of the book Visions of a Flying Machine by Peter Jakab. In this article, the subsequent six chapters of that book are critiqued. The article begins with a listing of the largely overlooked, but well documented and vital contributions to the Wrights' efforts made by Octave Chanute. The damage done to the historical record by Visions is summarized at the end of this article.
|Left: Peter Jakab’s Visions of a Flying Machine. Right: The Wrights’ mentor, Octave Chanute.|
Page 84: The Wrights’ relationship with Octave Chanute is discussed by saying that “Chanute provided the Wrights with little genuine technical assistance and few if any useful theoretical ideas.” This egregious falsehood is exactly opposite of the truth. According to records of their correspondence, Chanute provided the Wrights with, or alerted them to:
- His 1894 book that was the basis for their study of earlier works.
- Realizing the biggest problem remaining to be solved was control.
- The need to master control with gliders before adding power.
- Trussed biplane wing construction.
- First testing gliders unmanned with tethering lines.
- The best gliding areas are the coasts of Georgia and the Carolinas.
- His cohorts (Huffaker and Spratt) who showed the Wrights the reversal of the center of lift’s movement.
- Doing tests with a wind tunnel to determine better wing shapes.
- Photos of wind tunnels and the design of their lift balance.
- The basic design of a falling weight catapult enabling testing near Dayton and flying for the next six years.
In fact, it is evident that without these inputs the Wrights may well not have succeeded. If they did it would have taken them far longer, which may well have denied them the reputation of being the first to accomplish powered, manned flight.
Page 110: The claim is made that the wing tests at Kitty Hawk “confirmed their earlier assumption regarding the reversal of the center of pressure [lift].” As previously discussed in relation to page 65, the Wrights did not have an “earlier assumption regarding the reversal of the center of pressure”. They admitted that the Kitty Hawk tests suggested to them by Huffaker and Spratt in 1901 showing the reversal of center of pressure movement came as a complete surprise to them.
|Left: Dr. George Spratt (photo from the Harold E. Morehouse Flying Pioneers Biographies collection in the NASA archives); Right: Edward Huffaker|
Page 112: Here, the author’s shoddy research has led countless subsequent authors and historians into an unintended error. A discussion on the Wrights’ problem with wing warping drag is opened by saying “Wilbur took the next step and attempted to make an intentional turn with wing warping.” In fact, the Wrights, particularly Orville in his 1920 deposition, made it perfectly clear that they were not attempting turns at Kitty Hawk, but rather were simply trying to maintain heading and avoid spins while correcting inadvertent banking when they ran into the problem.
They had put anhedral or droop into their wings to facilitate traversing a hill without getting rolled and blown sideways into it. Unfortunately anhedral made their gliders unstable in roll since the higher wing would develop more lift than the low one. But when they used warping to bring the glider back level, the downward warp on the low wing gave that wing substantially more drag causing it to drag back and slow down so much that it actually lost lift. This made the vehicle spin and roll further into the bank rather than level out.
Describing this problem in his 1920 deposition, Orville testified that “Sometimes in warping the wings to restore lateral balance…” In another reference to roll control he stated “When the wings were warped in an attempt to recover lateral balance…” On page three of their 1906 patent, it says “…owing to various conditions of wind pressure and other causes, the body of the machine is apt to become unbalanced laterally…. The provision we have just described [wing warping with coordinated rudder] enables the operator to meet this difficulty and to preserve the lateral balance of the machine.” Nowhere does their 1906 patent address turning.
The Wrights also describe their glider spinning into the lower lagging wing and auguring it into the sand. The Wrights referred to this as “well digging”. Had they been trying to turn, the vehicle would have slipped straight toward the other side, which it didn’t.
Actually, with the rudder mechanically connected to the wing warping, and only deflecting enough to keep the 1902 vehicle going straight, both it and the 1903 Flyer couldn’t turn. In fact, the Wrights were only able to make turns after they disconnected the rudder from warping in 1905. However this error in the book, along with laziness and/or lack of understanding by subsequent authors and historians, has perpetrated to this day the myth of the Wrights practicing intentional turns at Kitty Hawk.
Chapter 6: "Seeking Answers: The Wrights Build a Wind Tunnel"
|A 1949 reproduction of the Wright Wind Tunnel by the National Cash Register company|
Page 119: This chapter launches into a two-chapter discussion of what was supposedly wrong with Lilienthal’s lift data to cause the Wrights to have lifting problems in 1900 and 1901. Right away it erroneously states that they used Lilienthal’s incorrect value of Smeaton’s coefficient for both of these vehicles. This is obviously wrong since wing area is proportional to Smeaton’s, and the ’01 vehicle had twice the wing area of the ’00.
This two-chapter discussion of what was “wrong” with Lilienthal’s data and how the Wrights “corrected” it with their wind tunnel, includes a whole series of falsehoods that have been repeated ad infinitum by authors and “experts” for over 30 years. The first blunder is saying that Lilienthal used Smeaton’s coefficient to calculate his lift coefficients from the equation
This is absolutely wrong since, as evident in Lilienthal’s book, Birdflight as the Basis of Aviation, he simply compared the lift on his wing sections at various angles of attack to their drag at 90 degrees. Since, at that time, the drag coefficient of any plate at 90 degrees was taken to be 1.0, the ratio of the pressures was the lift coefficient directly.
|Lilienthal's glider. Photo from britannica.com|
The next blunder was spending pages on what was wrong with the whirling arm device used back then by many experimenters to calculate lifting data. As its name implies, a long arm went round and round with a test section on its tip. Obviously the test section was (without a breeze) continually passing through its own wake of turbulent air which could cause errors. Lilienthal did use a 25-foot diameter whirling arm to calculate some of his data. However he also did tests in steady natural wind with no turbulence. Both of these data were plotted as “Plates” at the back of Lilienthal’s book.
|Lilienthal's whirling arm device.|
Later Lilienthal took the tabular data of lift coefficients for one of these plots and published it in James Means’ Aeronautical Annual. Anyone willing to go through the trouble to compare all of the table entries to the corresponding points on the plots in the back of Lilienthal’s book can see that the tabular data, which is all the Wrights had, exactly corresponds only to the points on the plot for a natural steady straight smooth wind. So, contrary to assertions in the subject book, the data the Wrights used had nothing to do with a whirling arm, or Smeaton’s coefficient.
|James Means' Aeronautical Annual|
Along with a lengthy discussion of the Wrights’ wind tunnel (we’ll get to that in a moment) the author spends a substantial part of the next 30 pages trying to say what could cause errors in Lilienthal’s data without actually determining anything. He uses the terms “could have”, “might”, “if”, “could be misleading”, “problems”, and “may have’s” without ever reaching a conclusion. The author’s task is made worthless by the fact that the Wrights admitted in a November 24, 1901 addition to a letter to Chanute (originally dated November 22, 1901) that the errors causing poor lift were theirs, not Lilienthal’s, and that there was nothing really wrong with Lilienthal’s data.
Page 124: Near the bottom of this page we are told that “the Wrights’ wind tunnel work best demonstrates their brilliance as engineers”. No mention is made of the fact that the idea and design of the tunnel was discussed with the Wrights by Chanute and his cohorts, Huffaker and Spratt, at Kitty Hawk. In fact, the subject was probably brought up by the Wrights’ guests since there is no mention anywhere of a tunnel by either of the brothers before then. As previously mentioned, during the summer of 1901, Chanute showed the Wrights photos of existing wind tunnels, and Spratt gave them the design of their “ingenious” and “inventive” lift balance with which to take test measurements.
|Visitors to Kitty Hawk: l-r Octave Chanute, Orville Wright, Edward C. Huffaker, and Wilbur Wright.|
In a letter to Chanute from October 16th, 1901, Wilbur refers to the photos, and in a letter to Dr. Spratt from October 16th, 1909, he discussed Spratt’s lift balance and claims he will be sure to give Spratt his due credit for the idea in the future. Orville also mentioned that the lift balance was Spratt’s idea in his sworn deposition for the 1920 Montgomery court case.
Throughout just this one chapter he lavishes gushing adjectives and phrases on the Wrights, including “imaginative, clever, conceptualizing, genius, marvels, ingenious, incredibly impressive, amazing, sophistication, inventive, visualizing, think through a problem clearly, and technical skill.” He even, on page 135, gives the Wrights credit for devising the scheme of calculating lift coefficients from force ratios and thus avoiding the use of the controversial Smeaton’s coefficient, not realizing, as was just discussed, that is exactly how Lilienthal did it ten years earlier.
Page 144: Here the erroneous claim that Lilienthal’s lift coefficients were wrong is repeated. A blunder trifecta is completed by repeating his claims that Lilienthal used a whirling arm and an incorrect Smeaton’s coefficient to generate the lift coefficients the Wrights used
Page 146: A plot of the Lilienthal lift coefficients versus angle of attack is presented along with the Wright data for a similar wing. This clearly shows that the data are basically coincident at the angles used in flight, and that Lilienthal’s data are more consistent than are the Wrights’ data. Not questioning the validity of his previous claims, the author merely attributes this data agreement to coincidence.
Pages 147 & 148: Here the author goes completely off the rails again saying that “Lilienthal’s….table had an even greater drawback” in that it could only be used for one wing shape! This statement is nothing short of bizarre. That is the purpose of lift coefficients, to express the different performances of differently shaped wings of the same size at the same flight conditions. This statement is exactly equivalent to saying that Volkswagen wheels are no good since they won’t work on a dump truck, or the recipe book has a drawback in that it calls for different temperatures or baking times for different dishes.
Page 149: While he’s out of his element, the author calls the fact that Lilienthal’s lift coefficient data can only be used for one given airfoil or wing shape a “stumbling block” and a “pitfall”. But farther down the page he magnanimously forgives Lilienthal’s “mistakes” because of all his “contributions to the advancement of aeronautics.”
Page 150: Here, after having sung their praises in previous chapters, the author finally acknowledges that the 1900 and 1901 Wright gliders had inadequate lift.
Page 152: The subject of induced drag is raised and the author ascribes the improved efficiency of the 1902 wings to an improved camber or curvature shape. Although the Wrights’ camber change probably changed lift coefficient somewhat, the vast majority of the reduction in induced drag was due to their more than doubling the aspect ratio from 1901 to 1902.
Page 153: The Wrights’ discovery of the significance of aspect ratio is mentioned here with no recognition that this was known by George Cayley a century earlier, and by many aviators in between. The Wrights could have learned this, years earlier, simply by reading. He also fails to mention that, along with changing their wing camber shape to much like that used by their more successful predecessors, they also changed their wing’s aspect ratio from 3.1 to 6.5, exactly the value used by Lilienthal on his test wings.
|Sir George Cayley|
Page 156: Reprinted here is Orville’s boast about how their predecessors were so ignorant of camber that they all used highly inefficient shapes and none had developed good data. Orville wrote “we possessed in 1902 more data on cambered surfaces, a hundred times over, than all of our predecessors put together.” Unfortunately this author, and apparently all others, are unaware that although the Wrights may have had more data that any others, they totally failed to understand the basic aerodynamic principal that caused their data
But their predecessors, Augustus Herring, Horatio Phillips, and Otto Lilienthal, did understand lift. They all knew that the primary cause of lift on a cambered wing was lowered pressures on its upper surface. The Wrights thought it was all due to pressure on the bottom of a wing that met the flow at a positive angle. In fact, that’s why they always used the term “center of pressure” (on the bottom of the wing) instead of center of lift (on the top surface).
In their 1906 patent they stated that their aircraft were “…supported in the air by reason of the contact between the air and the under surface of one or more aeroplanes [wings], the contact surface being presented at a small angle of incidence to the air.” They thought the only purpose of camber was to allow the wind to impact the forward upper surface of the wing to keep it from flipping over backwards. They held this erroneous belief for years after creating their powered airplanes.
Chapter 8: "'We Now Hold All Records!'"
Page 175: The author claims that the moveable rudder “provide[s] another instance of the presence of visual thinking in the Wrights’ inventive method.” Unfortunately their “visual thinking” did not recognize the problem of warp induced yaw beforehand, and that the fixed rudder, which they tried first, would make the problem worse.
Chapter 9: "The Dream Fulfilled"
Page 184: Yet another example of careless research is the claim that, in the Wrights’ first patent granted in 1906 “No mention of power is made in the claims.” In fact on page 1, lines 12-15, the patent states “….[the] aeroplanes [wings] are moved through the air edgewise at a small angle of incidence either by theapplication of mechanical power or by the utilization of the force of gravity.”
Page 186: Another try at belittling Octave Chanute is made by claiming that his statement that three-axis control was “ancient and well known” showed “almost unfathomable ignorance on the part of Chanute.” This claim actually shows “unfathomable ignorance” of the history of flight by a Director of the Smithsonian’s National Air and Space Museum. The concept of three-axis control was evident in a few glider concepts and vehicles, including Professor John Montgomery’s in the 1880s and going as far back as Le Bris’ 1857 glider which had wing warping and moveable horizontal and vertical tail surfaces. Moreover, the argument can be made that the Wrights didn’t actually have three-axis control until 1905 since their earlier vehicles all had vertical rudders only as an adjunct to wing warping to make the roll control work as intended. Those vehicles could only erratically control pitch and recover from inadvertent rolls, but could not intentionally execute turns.
|The 1857 flight patent by Jean-Marie Le Bris|
Page 189: We are told how Wilbur and Orville “cleverly used their tables…and lift and drag equations to determine the ….power requirements for the aircraft.” Unfortunately they were only “clever” enough to do it for level ground skimming flight. They did not heed warnings going all the way back to Cayley a century earlier, that an airplane would need additional power for taking off and climbing away from the ground. As a result, their aircraft could not “raise itself by its own power into the air” as they so proudly claimed in their post-1903 statements. In fact, their airplanes could not climb out of ground effect until 1905, and could not achieve flight without the help of strong headwinds or a catapult until late 1910, long after numerous other aircraft were routinely doing so.
Pages 194-198: On these pages the Wrights are lauded for making the “intellectual leap” that a propeller was just a wing moving in a spiral pattern and thus needed to be made up of cambered sections twisted as they went out from the hub to account for their increasing speeds through the air. Actually, this exact concept was presented to the Aeronautical Society of Great Britain in 1885 by Sidney Hollands and published in the U.S. by Chanute in February, 1893. (See the previous article Propelled to Absurd Heights by Paul Jackson in the January 26th, 2020 posting of this blog.)
|Sidney Hollands, pioneer of the modern propeller|
In fact, Hollands went the Wrights one better by also pointing out that the blades should be tapered as they progressed out from the hub to minimize bending loads and aerodynamic tip losses. It was primarily the increasing blade widths of the Wrights’ propellers that limited their efficiencies to around 65 percent. It may well also be this excessive tip loading that contributed to one splitting and causing Orville to crash during a 1908 demonstration at Ft Myer, killing Lt. Tom Selfridge and braking Orville’s back.
Page 206: The assertion is made that the Wrights use of a 60-foot launching rail would “make it clear that the  takeoff[s] had been unassisted, allaying any possible doubts that the Flyer had made a true flight.” However the author says nothing about the fact that at Kitty Hawk, on the morning of December 17th, 1903, the 27 mph headwind with gusts even higher, supplied at least 90 percent of the airspeed, and over 80 percent of the lift required to get the Flyer into the air. It was almost flying sitting still without the engine and propellers turning. In fact, later that day the unattended vehicle did just that, the wind raising it up and rolling it over, destroying it. It would seem this wind constituted an essential assist and could raise, in Jakab’s words, “doubts that the Flyer had made a true flight.”
Chapter 10: "The Meaning of Invention"
Page 213: Although previous chapters lauded the Wrights’ “three-axis control” as enabling their 1902 glider to make turns, here that is directly contradicted by stating that “Before marketing their invention was possible, they would have to be able to make turns”. The author correctly points out that this was the purpose of their testing in 1904 and 1905 at Huffman Prairie, seemingly oblivious to the fact that he has made yet another contradiction within his own book.
|l to r: 1902 Wright glider, 1903 Wright flyer, 1905 Wright flyer|
Page 217: After spending the whole book describing the Wrights’ fabulously inventive genius, the book winds up by saying on the last page that “with the exception of the propellers, there was nothing fundamentally original about the way in which the 1903 machine was designed”. But as a last treat, two paragraphs down the author yet again demonstrates a somewhat schizophrenic style by following that statement with “they invented a fundamentally new technology.”
At this point I am somewhat at a loss for words to conclude this review. Not only is this the most inaccurate and confused book on the Wrights I have ever read, it is also possibly the most inaccurate record of technological history. And it was written by an Associate Director of the World’s premier aviation museum along with the help of some supposedly qualified technical contributors. Possibly some pressing deadline was imposed on the book preventing any real research. Or perhaps the intent was to do America a service by deifying two of its favorite sons. But still, these would not explain the numerous contradictions.
The real shame is that so many of the errors in this book have become part of the accepted historical record, and been repeated many times over, for decades, in subsequent books and media. This book seems to be yet another example of authority trumping truth.