The Wrong Wright Story Series #4: The Invention of the Aerial Age

 

 The Wrong Wright Story Series #4:

The Wright Brothers and the Invention of the Aerial Age

By Joe Bullmer 

This, the fourth article in this series, addresses the book The Wright Brothers and the Invention of the Aerial Age, ISBN-0-7922-6985-3, a 2003 publication of the Smithsonian press. It was cowritten by the authors of the last two books addressed in this series, Tom Crouch, the Senior Curator for Aeronautics, and Peter Jakab, an Associate Director of the National Air and Space Museum. As one might expect, many of the mistakes by these authors noted in the previous reviews of their individual books are repeated in this book. Most are at least briefly mentioned here since an effort was made to make each of these articles complete.

The authors from left, Tom Crouch , Senior Curator, Ret., Smithsonian NASM, and Peter Jakab, Chief Curator, NASM.

Again, the period from 1899 through 1905 is specifically addressed since this is the period during which the Wrights developed a controllable powered airplane. However the period after that up to Orville’s death is also covered in the subject book, so a few comments on that are included. 

Page 48: Combining two of the sentences in the sixth paragraph, they collectively say “an airplane pilot…..must make constant control movements…..to stay in the air”. As stated in previous articles, anyone at all familiar with flight knows that, once a properly designed airplane is trimmed out, no control movements are necessary to maintain steady straight flight in reasonably smooth air.

Page 51: The authors discuss conflicting statements by the brothers regarding how they came up with wing warping, but don’t mention that twisting wings for control had been done by a number of the Wrights’ predecessors, a few even patenting it. This was also covered in Chanute’s book which the Wrights obtained in 1899.

Page 53: They claim warping was superior to previous methods of control. But separate winglets and ailerons, both causing less drag imbalance and thus superior to warping, had already been used by others. Eventually warping would be abandoned, even by the Wrights, in favor of ailerons.

Page 56: Here adulation for the Wrights’ supposed ability to correctly “visualize aerodynamics” gush forth once more. And again the statements made are not true. The comment in the second article of this series for page 66 of Jakab’s Visions lists seven examples of the Wrights’ failure to properly envision air flow and its effects. These reveal no basis for fantasizing about the Wrights' aerodynamic clairvoyance.

Page 57:  The often-repeated comment on the similarity of airplanes to bicycles is made, to wit, since they both bank to turn, they must both be constantly rebalanced. Although every aviator knows this is wrong, this assertion has become standard fare among aviation historians discussing the Wrights.

Page 58: Here they repeat a whole series of errors on the Wrights’ wing design that were first stated in Visions of a Flying Machine. First, that the Wrights initially used Lilienthal’s camber shape which they didn’t, an error that plagued them with inadequate lift for a couple years until their wind tunnel showed that they had to use Lilienthal’s basic wing shapes. 

Then the Wrights are credited with discovering the center-of-pressure (actually lift) reversal on wings by just thinking about it. In fact, they never knew of the reversal of center of “pressure” movement until Dr. George Spratt and Edward Huffaker, visitors to their camp in 1901, told them about it. Then their visitors proceeded to prove it with tests showing where one of the Wrights’ wings balanced at various angles of attack.

Dr. George Spratt and Edward Huffaker.
Visitors to the Wright camp in 1901, these aviation pioneers taught the Wright Brothers about the reversal of the center of pressure movement on the wing of a plane.

Finally, this rant is concluded by claiming an aircraft is in equilibrium when the center of pressure (lift) coincides with the center of gravity. This is not really true unless the vehicle’s configuration is such that it tends to remain that way. Equilibrium is not a fleeting instantaneous condition. That was the basic problem with all early Wright aircraft. They had no inherent stability allowing them to maintain a state of equilibrium. The Wrights both wrote of their surprise at learning this.

Page 61: Here the authors make an astounding blunder only equaled by the Wrights having made the same mistake. They talk about moving “the center of pressure on the bottom of the wing” back and forth to regain coincidence with the center of gravity to maintain balance. This sounds as though they didn’t know that what they called the center of pressure on the bottom is actually the center of lift which primarily results from a partial vacuum on the top of the wing. This distinction is crucial to understanding the science behind the movement of the center of lift.

In the next paragraph a truly staggering blunder is made by saying that a constantly moving elevator is used by every airplane today to maintain balance with the constantly moving center of “pressure”. Apparently they have no concept of how a trimmed horizontal stabilizer is set to stabilize an airplane so that no elevator movements are required to keep it there.

Page 62: Here the assertion is made that the greater efficiency of a cambered surface (as opposed to a flat one) had been established by 1900. Actually Sir George Cayley established that nearly a century earlier in 1804. That’s why cambered wings had been used by most aviators since then.

Sir George Cayley, aviation pioneer, who established by 1804 that a cambered wing is more
efficient than a flat one.

They go on to give the Wrights’ erroneous thinking that led them to put all of the camber within the front ten percent of the wings, without mentioning that this degraded both lift and longitudinal stability. Finally, they claim incorrectly that Lilienthal used a wing maximum camber that was eight percent of the wing chord whereas the Wrights used five percent. Actually, Lilienthal also used five percent on his gliders.

Chapter 3

Octave Chanute, mentor to the Wright Brothers.

Page 68: Here the absolute falsehood that “Octave Chanute provided the Wrights with little genuine technical assistance and few, if any, useful theoretical ideas” is repeated. This was also stated on page 84 of Jakab’s solo book Visions of a Flying Machine. This statement is so egregious that I will repeat here, in full, the comments I made in that Critique:

According to records of their correspondence, Chanute provided the Wrights with:

• His 1894 book that was the basis for their study of earlier aviation.
• Realizing the biggest problem remaining to be solved was control.
• The need to master control with gliders before adding power.
• Trussed biplane wing construction according to both brothers’ statements.
• The idea of first testing gliders unmanned with tethering lines.
• The best gliding areas being the coasts of Georgia and the Carolinas.
• His cohorts Huffaker and Dr. Spratt showing the Wrights the critical reversal of the center of lift’s movement, thus largely solving their control problem.
• Doing tests with a wind tunnel to determine better wing shapes.
• Photos of wind tunnels and the design of their lift/drag balance.
• The basic design of a falling weight catapult enabling them to achieve controllability and maneuverability through testing near Dayton, and enabling all of their 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, probably denying them the distinction of being considered the first to accomplish powered, controlled, manned flight.

Pages 72 & 76: The gliding tests at Kitty Hawk in 1900 are described as validating the pitch and roll controls. In fact, the machine had such poor lifting capability that it was mostly tested unmanned and tethered. Finally, with winds exceeding 20 knots, Wilbur managed just a few short hops, almost all with erratic pitch control and the warping inoperable.

Page 77: They claim the Wrights discovered the reversal of their wing warping roll control by attempting turns. This is absolutely not true. They discovered it by trying to maintain a constant heading while correcting inadvertent rolls caused by wind gusts and the anhedral, or droop, in their wings. They were not interested in developing a turning capability at Kitty Hawk, and the 1902 and 1903 vehicles could not execute intentional turns.

In their first patent they stated that “the machine is apt to become unbalanced laterally” and “The provision which we have just described [mechanically linked warp and rudder] enables the operator to meet this difficulty and preserve the lateral balance of the machine.” In other words, to keep the machine flying straight and level, not to turn. They did not attempt turns until 1904 near Dayton, and could not reliably accomplish them until October of 1905.

In his sworn deposition for the Montgomery case Orville testified, “Sometimes in warping the wings to restore lateral balance….” and “When the wings were warped in an attempt to recover balance….”.  Clearly, they were attempting to fly level, not turn, when they discovered warp reversal. In spite of these numerous absolutely clear statements directly contradicting these books, every “historian” since these books were published parrots this same error. Tour guides in the Air and Space Museum still repeat it.

Pages 84-89: On these pages the authors attempt to once more heap credit upon the Wrights for something they didn’t think of by simply saying that “the Wrights decided to build a wind tunnel”. Reiterating, the subject was brought up during talks with Chanute, Spratt, and Huffaker when they visited the Wrights at Kitty Hawk during the summer of 1901. There is no mention of such a device in any of the Wrights’ records before then. During that discussion Chanute showed them photos of wind tunnel components, and Dr. Spratt showed them the scheme for the lift vs drag balance that the authors credit the Wrights with as a “brilliant intuitive leap”. The Wrights admitted they got this information from their visitors in later correspondence and a legal document, including Wilbur's letters of 10/16/1901 and 10/16/1909 and Orville's sworn affadavit for the 1920 Montgomery case.

These authors go on to write “The brothers’ artful weaving of their clear, straight forward conceptualization of the problem and their clever, effective means of experimentally obtaining results illustrates the Wrights’ engineering talents at their finest.” All this for equipment and procedures that were shown to them by visitors at Kitty Hawk, visitors to whom these authors give no credit at all for providing any help.

The authors also claim that the tunnel tests showed Lilienthal’s lift data to be “off” and that the tunnel allowed them to determine a more correct value of Smeaton’s coefficient. These are both colossal untruths. In fact, Wilbur informed Chanute that they had arrived at the correct value of Smeaton’s coefficient (actually the same value as that determined by professor Langley at the Smithsonian) from gliding data months before they built the tunnel. On 11/24/1901, Wilbur wrote Chanute that “for a surface….like that described in his [Lilienthal’s] book [his] table is probably as near correct as it is possible”.

The authors also wrote that “The wind tunnel experiments showed the brothers that long, narrow wings [i.e., higher aspect ratio wings] are more efficient than short, wide ones….”. Since Cayley published this in 1804, they also could have discovered it years earlier by simply reading. They subsequently abandoned their aspect ratio of 3.1 and adopted Lilienthal’s favored value of 6.5 for their 1902 glider.

Finally, on November 24^th, 1901 Wilbur wrote Chanute that “It is very evident….that a table based on one aspect [ratio] and [wing section] profile is worthless for a surface with different aspect and curvature. This no doubt explains why we had so much trouble figuring our machines from Lilienthal’s table.” In other words, the Wrights admitted, in writing, that their tunnel showed them that different wing shapes produce different lift coefficients. So the Wrights admitted that their lift problems were their own fault, and nothing was wrong with Lilienthal’s data.

These astounding and egregious errors by these authors have led to everyone who has ever written or spoken about the Wrights since, repeating their same false statements. They can be seen in museums, on placards, in numerous books, and heard in nearly all documentaries. Thus, important technical history has been falsified by careless, incompetent research at the highest levels of a Smithsonian museum.

Pages 89 & 90: Here they extol the virtues of tethered testing, what the Wrights called “flying it as a kite”, as though it was yet another wonderful idea the Wrights originated, although their copy of Chanute’s book has a whole section on kite-style tethered testing.

Wilbur left, Orville right, “flying it as a kite.”

They also fail to mention that when kiting, the brothers, being nearly 20 feet apart (one at each wing tip), couldn’t tell that when warping was applied, one end of the wings were pulling on the lines harder than those on the other end. So the tendency of warping to cause the vehicle to yaw, then bank even steeper, and finally spin into the ground, was completely masked to them. This actually set them back a couple years until they had enough lift to do extensive free glides and address the problem in 1902. Another aid in solving the spin problem may well have been their wind tunnel which clearly demonstrated the effect on a wing’s drag by a small change in its angle of attack.

Page 91: This page is ripe with exaggerations concerning the Wrights’ wind tunnel. These authors write that the device “carried the progress toward mechanical flight to another new plateau”. But of course, once more, they don’t mention that this was thanks to Chanute and his cohorts at Kitty Hawk.

Next a comment, similar to one in Visions, is made claiming that after the tunnel tests, the 1902 vehicle “flew just as a 747 or modern jet fighter flies”. Well yes, it used cambered wings and could go in the air in a straight line fairly level, but it couldn’t turn or maneuver, rather desirable qualities in a 747 or fighter plane. In fact, it would take three more years for the Wrights to develop limited versions of these capabilities in their aircraft. By the end of 1905 the aircraft the authors refer to as “only refined” had lengthened structure, relocated center of gravity, changed location, size, and loading of the canard, a fundamentally altered version of their patented control scheme, modified propellers, and oil, fuel, and water pumps added to the 1903 engine. Some “refinements”.

Chapter 4

Page 119 & 120: Picturing a propeller as a rotating wing is characterized as a “breakthrough” and an “intellectual leap”. If it appeared so, it was only because of a lack of research by the authors. As explained in the last article, Sydney Hollands presented the concept of a propeller as a vertically rotating cambered twisted wing at a meeting of England’s Aeronautical Society in 1885. In fact, he also pointed out that it should be tapered toward the tips of the blades, something the Wrights totally missed. Hollands even gave values for the twist angles. All this was covered in Chanute’s book which the Wrights obtained four years earlier. Nonetheless, this "intellectual leap" is another falsehood that has become a staple in subsequent accounts of the Wrights’ work.

Wright propeller reproductions (from Ash, Robert & Miley, Stanley & Landman, Drew. (2001).
Evolution of Wright Flyer Propellers between 1903 and 1912 By. 10.2514/6.2001-309.)

The propellers of the Sopwith Camel, a World War I British fighter, clearly show
a taper toward the tips of the blades.

In fact, three other designers of ships’ propellers, Lanchester in England, Drzweiecki in France, and Prandtl in Germany, had also addressed the design of air propellers as cambered twisted rotating wings. Chanute provided material on Drzweiecki’s work to the Wrights in 1903.

Also mentioned on page 120 is that, for the 1903 powered airplane, the Wrights chose a maximum wing camber depth of five percent. As previously mentioned, and contrary to assertions in this book, that is precisely the camber depth used and recommended by Otto Lilienthal on his gliders.

Otto Lillienthal poised for a glide.

Page 121: At the top of this page they claim that one of the “instruments” the Wrights had onboard in 1903 was a tachometer for both the engine and propellers. In fact they had no tachometer. All they had was a total revolution counter for the engine. This, in combination with the stopwatch, would yield the average engine rpm for a flight attempt. This is a minor unimportant point, but these kinds of totally unnecessary errors lead one to wonder what kind of research was done, and by whom, for this book.

Page 130: The first three flight attempts on December 17^th, 1903 are discussed without mentioning that none of them were actually measured for time or distance. These were simply estimated by the Wrights. Also, they don’t tell us that, according to the Wrights’ descriptions, the aircraft was out of control throughout all three attempts. Finally they don’t mention the 27 mph headwind plus gusts that supplied 90% of the airspeed and 80% of the lift required for the airplane to leave the ground. Without those head winds there would have been absolutely no flying at all by the Wrights in 1903. This is proven by their 1904 aircraft not being able to leave the ground with light winds at Dayton, although it had more power and launch rails up to four times longer.

Page 131: Here the authors discuss the fourth attempt, Wilbur’s last, without telling us the aircraft was out of control at its beginning and end, the Wrights claiming it only flew fairly level for a short period during the middle of the trial. They quote the Wrights’ claim for that attempt as lasting 59 seconds and covering 852 feet, a distance the Wrights said they measured.

Four decades later Orville identified a photograph as having been taken after the end of that attempt. But four independent measurement calculations on the photo, by four different people, using four different methodologies, reveal the aircraft to be between 250 and 280 feet from the end of the launch rail. Also, the propellers are stopped and three dark objects at least three feet tall are on the center of the lower wing. This is all clearly shown on a large cropped version of the photo on pages 126 and 127 of this very book.

At the bottom of this page one of Jakab’s contradictions reappears with the statement that, in spite of the success of the 1903 airplane, “marketing and exploiting the [Wright’s] technology would require an aircraft capable of making turns….”. While correct, this is in direct contradiction to the statement back on page 90 claiming that even the 1902 glider could make coordinated turns.

Page 133: The claim from the Visions book that the Wrights invented a “fundamentally new technology” is repeated here. It’s not clear what fundamentals they are talking about since the only feature of Wright aircraft (besides engines and drive chains) that hadn’t been used by predecessors, namely mechanically coordinated roll and yaw controls, had to be abandoned in 1905 in order to make turns.

Chapter 5

Diagram from the famous Wright patent, granted in 1906.

This chapter, discussing the Wrights’ patents and early efforts to sell their airplanes, is most noteworthy for its numerous omissions. It discusses their first patent without mentioning that it

• Gave a totally incorrect explanation of how their aircraft were actually able to fly.
• Locked them into a configuration that was dangerous and rejected by other designers.
• Had the primary purpose of protecting a control system they already had to abandon.
• Was intended to freeze out competition worldwide, but primarily stifled aviation research and production only in the U.S.

The chapter also discusses the Ft. Myer crash that killed Lt. Tom Selfridge, the world’s first airplane fatality. Although the authors relate that the crash was due to a propeller failure, they don’t mention that one of the propellers had previously split and had been hastily repaired with glue and nails. What’s more, the split was at a tip, their propeller tips being excessively loaded due to the improper reverse taper of the blades.

The Flyer - and propellers - that crashed in 1908, killing Lt. Thomas Selfridge.

Chapter 6

Page 196: This chapter covers the period up to World War One. At the bottom of this page they mention that “The world was not beating a path to their [the Wrights’] door in a mad rush to buy flying machines.” No mention is made of the fact that numerous competitors were doing quite well. That was because Wright airplanes were considered obsolete, poor performing, hard and dangerous to fly, with no useful capabilities beyond lifting someone into the air. Many other countries were buying hundreds of safer, more capable aircraft from their indigenous manufacturers.

Page 199: The book mentions that flying exhibitions were quite profitable at that time. But it does not reveal that Glenn Curtiss paid his pilots and crews far more generously than did the Wrights. That, along with safer and better performing airplanes, enabled him to put on far more thrilling shows. Most of the Wrights' exhibition pilots were killed in their first fifteen months of flying.

Chapter 7

This chapter discusses the era between Wilbur’s death in 1912 and Orville’s in 1948, in particular the wrangling between the Smithsonian and the Wright family regarding the Smithsonian’s claims that Langley’s “Aerodrome“ aircraft was “the first airplane capable of manned flight”. It also contains one last enrichment of the Wright image by avoiding mentioning Orville’s disownment of his sister Katherine when she got married.

She abandoned her young teaching career to care for Orville after his back injury at Ft. Myer in 1908 and never went back to teaching. After devoting her life to her brothers and their aircraft business, finally in 1926 she decided to marry an old college sweetheart. Upon hearing of her marriage plans, Orville disowned her for “abandoning” him. Unfortunately, she was to have only two years of marriage before dying of pneumonia. But Orville had refused to have any contact with her until she was on her deathbed. This episode may well provide some insight into the attitudes he had regarding employees, their competition, the Smithsonian, and his legacy.

Pages 216 – 232: The book concludes with seven photos and over ten pages of text discussing the protracted, nearly four decades, of feuding between Orville Wright and the Smithsonian over who actually came up with the first airplane capable of manned powered flight. Was it the Wrights or Professor Langley, the director of the museum at that time, and creator of the ill-fated “Aerodrome”. In a pique, Orville sent the 1903 Wright “Flyer” to England for exhibition rather than give it to the Smithsonian. Finally, after WWII, a contract was signed, with the Wrights agreeing to bring the Flyer back for exhibit in the Smithsonian in 1948.

The relevant passage of the Wright-Smithsonian contract.

One wonders if this has something to do with museum personnel going out of their way to aggrandize the capabilities and accomplishments of Wilbur and Orville at every opportunity. This also explains why they avoid the issue of Wright aircraft not being able to take off unassisted until 1910. If the Smithsonian admitted this, it would be difficult to deny that numerous other aircraft were fully capable long before the Wrights were.

Summary

Unlike the previous discussions, for this book specific sources for specific comments were not always referenced in this article. This publication is more in the nature of a “coffee table” picture book than were those. Still, its common use as source material warranted it’s review here.

This book’s value is actually in the photographs presented. Its large size and print quality, along with the quantity and enhanced quality of the photos are outstanding. However the value of its text is another matter entirely. Perhaps the motivation of the authors may have again been to instill admiration and pride in Americans (and in their museum) by explaining all the Wrights’ accomplishments as due entirely to their “brilliance” and “genius”.

But as an American, I am offended at such inadequate research and frequent fabrication as this coming from the top levels of a Smithsonian Museum. This is an Institution supported by American citizens, and expected to be the world leader in such research. The Smithsonian evidently does world class research on non-technical historical subjects, and in some technical areas. Evidently its history majors and PhDs are capable in such areas. However with the Wright brothers they stepped off into a highly technical area for which they were obviously unprepared. Worse yet, there existed a plethora of records of the Wrights’ work which largely refutes nearly all of their guesses and fabrications. And perhaps worst of all, those eager to take credit for such publications as these by claiming authorship evidently were completely unqualified to verify contributions to their publications.

It’s easy to find out such information as the ten vital contributions to the Wrights’ work provided by Octave Chanute, or a half dozen examples of the Wrights’ wrong guesses at aerodynamics, or indeed all the other falsehoods cited in these critiques. All one need do is simply read and comprehend all of the first volume of Marvin McFarland’s compilation of original Wright-related correspondence and records, along with Orville’s 1920 affidavit. These resources were in existence at least a half century before the books addressed in this series were written and published by the Smithsonian.

In recent years it has become evident that many people are quite comfortable with fantasies in place of truth. However, having devoted much of my professional life to the science of aeronautical theory, design, and performance, I cannot ignore the origin of the entire technology being falsified. So, along with a growing contingent of others, I will continue to contribute to the establishment of truthinaviationhistory. 

——————————————————————————————————————————

Author Joe Bullmer has a Masters Degree in Aeronautical Engineering from the University of Michigan with additional graduate studies in the subject (the exact same academic background as Kelley Johnson, designer of the U-2 and SR-71). He subsequently worked in aircraft design and performance and related subjects for the United States Air Force for thirty years. A substantial portion of this time was spent as an aircraft performance engineer at Wright-Patterson Air Force Base. During that time he had the rare opportunity to work with some of the top designers at Boeing, North American, General Dynamics, Lockheed (including Kelly), and McDonnell corporations.  He also collaborated with some of the best designers in the U.S. Air Force.

 

His areas of greatest interest have always been aerodynamics and stability and control. These are the keys to understanding the thoughts and testing of the Wright brothers.

 

Much of his work was in the field of technical intelligence. In this capacity he often was examining someone else’s airplane designs and determining what they did, why, and what the resulting performance would be. This turned out to be excellent preparation for his book since it is precisely what he had to do with the Wright brothers, designs. Intelligence work also developed his investigative and deductive skills which are prerequisites for any historical investigation.

 

Joe has presented aircraft design and performance briefings to U.S. Congressional and Senate committees, Presidential Cabinet members, and at the White House. Now 77, he has been retired for 25 years and has written The WRight Story, and a number of articles on early aviation. He maintains contact with a number of designers, flight test engineers, pilots, and historians.

The Wrong Wright Story Series #2: Visions of a Flying Machine (Part II)

The Wrong Wright Story Series #2

Peter Jakab's Visions of a Flying Machine (Part II)

By Joe Bullmer

Introduction to Part II

The previous article in Truth in Aviation History 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.

 

 Chapter 5: "Riding the Winds"

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 16^th, 1901, Wilbur refers to the photos, and in a letter to Dr. Spratt from October 16^th, 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 26^th, 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 [1903] 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 17^th, 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.”

 

Summary

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.

--Joe Bullmer

The Wrong Wright Story Series #2 - Visions of a Flying Machine (Part I)

The Wrong Wright Story Series #2

Peter Jakab's Visions of a Flying Machine (Part I)

By Joe Bullmer

Left: Peter L. Jakab of the Smithsonian Institution; Right: Jakab's book Visions of a Flying Machine

Introduction to the Wrong Wright Story series:

This is the second in a series of critical reviews of four books and a television documentary about the Wright brothers’ creation of an airplane. The books include a biography authorized by Orville Wright, and three more by senior officials of the Smithsonian’s National Air and Space Museum. This article refers to the paperback reissue of Visions ofa Flying Machine by Associate Director Peter Jakab, published in 1990 by the Smithsonian Press, ISBN 1-56098-748-0.

These books were chosen because they have been used as source material for dozens of other publications containing discussions of the Wright brothers’ work and accomplishments. The NOVA documentary Wright Brothers' Flying Machineis perhaps the most prominent of approximately a dozen produced since 2003 portraying the invention of the airplane.

These five accounts all contain numerous fabrications and false statements that contradict the Wright brothers’ original records, the records of other aviation researchers who preceded the Wrights, and even aviation science. Unfortunately, other authors have relied on these books as bases from which to launch into discussions of the Wrights’ work. As a result, nearly every source of information on the Wright brothers’ work is contaminated with some of these same falsehoods and errors.

This series of articles represents an attempt by this author to establish “truthinaviationhistory” concerning the work of the Wright brothers. With this goal in mind, any technically qualified rebuttal to these critiques, or criticism of The WRight Story, would be welcomed.

Visions of a Flying Machine: Overview

It may seem unlikely that a book with such an extensive list of contributors in its Acknowledgements section as Visions would contain so many errors. However, only three contributors are credited with technical qualifications. One of these made similar errors in his books, which subsequent articles in this series will reveal. The others have published only limited writings on the Wright brothers, indicating only limited research.

A couple years of researching thousands of pages of original records of the Wrights and their predecessors resulted in my publishing a book in 2009 titled The WRight Story. Reliable primary and secondary sources were consulted for historical events preceding the Wrights and those after 1905. However, only original Wright material was consulted for all descriptions of their work resulting in a successful airplane by October of 1905. Surviving authors and producers of the works discussed in these reviews were contacted in an effort to discuss and resolve differences, but none have expressed interest in pursuing a dialogue.

A first reading of the book being discussed in this article revealed over 160 exaggerations or errors. Just addressing the 43 listed here precluded citing complete sources for each comment. However, eliminating more would be an injustice to portraying the nature of the book.

Chapter 1: "Why Wilbur and Orville?"

Page 15: The author claims “The majority of the critical elements in the airplane were original to the Wrights.” Actually, Wilbur admitted that the truss biplane structure was copied from the Chanute/Herring glider, their successful post-1902 wing camber and aspect ratios were essentially those used by numerous predecessors, and wing warping had already been used and patented by at least three experimenters. Cambered twisted propellers had also been recommended by a few predecessors, and even the forward elevator was a feature of Maxim’s 1894 machine. The only feature “original to the Wrights”, opposable wing warping with a mechanically coordinated rudder, had to be abandoned by them in 1905 in order to make turns.

The Chanute/Herring glider

Page 16: Here he repeats, writing that “Much of what the Wrights accomplished was highly original.” These comments are the first examples of the author's frequent contradictions, since page 217 says that “with the exception of the propellers, there was nothing fundamentally original about the way in which (sic) 1903 machine was designed”. In a sort of double reverse, the next paragraph on 217 says “they invented a fundamentally new technology.”

Chapter 2: "Aeronautics before the Airplane"

Page 33: The author claims that “Using [Otto Lilienthal’s] data and tables, an experimenter could easily calculate the size wing required to support a given weight at a particular velocity.” Then on pages 143 to 149 he talks about how bad he thinks Lilienthal’s data was. This is another unresolved contradiction in the book.

Chapter 3: "'You Must Mount a Machine'"

Page 46: The author writes, “[Lilienthal] failed to see that [weight shifting] was a dead end as far as a large, powered aircraft was concerned.” Actually Lilienthal did not “fail to see that.” On page 284 of the current edition of his book Birdflight as the Basis of Aviation, Lilienthal pointed out that although wings twice as big would be more optimum for gliding, he felt he couldn’t safely handle gliders larger than about 160 square feet with just weight shifting. In the 1896 edition of James Means’ TheAeronautical Annual, Lilienthal reported that he was well aware aerodynamic methods would be necessary to control larger aircraft. In fact, he was collaborating with other German experimenters on the design of such controls and had begun experimenting with them. Some claim it was actually a failure of one of these devices, rather than a piloting mistake, that resulted in his fatal crash.

Left: Lilienthal's Birdflight as the Basis of Aviation; Right: Chanute's Progress in Flying Machines.

Page 48: Here the Wrights are given credit for being the first to realize that control was the most important problem to solve. But in his 1894 book Progress in Flying Machines, the Wrights’ principal research source, Chanute stated that experimenters should direct their attention to gliding or “soaring” flight, and that the “maintenance of equilibrium….was by far the most important aspect of flight yet to be solved”. Nonetheless, in the book under discussion, this author goes on to say that “The Wrights’ recognition of the centrality of control…was…the premier conceptual leap that set them apart from their predecessors and their contemporaries.” He apparently has no idea that they read it in Octave Chanute’s book.

In the next paragraph, Alphonse Penaud is given credit for developing dihedral for roll stability during the 1870s. Yet again a lack of research is evident. Sir George Cayley invented dihedral and reported on it in the November, 1809 issue of Nicholson’s Journal of Natural Philosophy, Chemistry, and the Arts.

Page 49: The careless claim is made that “proponents of inherent stability gave no thought whatsoever to controlling or steering their machines.” adding “Many reasoned that if simple straight-line flight was achieved, control could be easily dealt with later.” This completely misses the fact that that is precisely the approach the Wright brothers took, concentrating solely on achieving straight line flight until 1904, then beginning attempts at maneuvering and turning, finally accomplishing these by October, 1905. They stated this many times, even in their patent, wherein on page three, lines 78 to 87, they explained that their moveable coordinated rudder was invented to maintain straight and level flight.

Page 50: In the second paragraph a severe lack of knowledge of aircraft design is exhibited by the author. He states “The Wrights were the first to see that control was [for airplanes] the very essence of maintaining equilibrium.” Actually, until recently all airplanes have been designed such that, once trimmed, they maintain equilibrium completely by their aerodynamic design without any control movements whatsoever. This was true of airplanes immediately following the Wright Flyers, and is largely what caused the Wrights to eventually totally change their designs not long before going out of business.

Later in the paragraph the author's lack of knowledge is confirmed by saying “…just as a cyclist must make constant control movements to stay on two wheels, the airplane pilot must exercise similar authority over his craft to stay in the air.” Anyone who has ever flown in an airplane, or even seen a film of a pilot flying one, should know this is not true. Even more astounding is the number of “aviation historians” that have confidently parroted these absurd statements in their books and TV appearances.

Page 51: The Wrights’ experience of riding bicycles is given credit for the idea of banking an airplane in order to turn. This is another fallacy that has been picked up by countless authors and “aviation historians.” It’s quite likely that some cavemen, over 100,000 years ago, noticed that birds always bank when they turn.

Page 58: Here and on the next page indecision is expressed as to whether or not the Wrights copied the trussed biplane design of the Chanute/Herring glider of 1896. Again, lack of research glares out. The Wrights both said they did! In a December 21^st, 1909 letter Wilbur wrote, “We have repeatedly acknowledged our indebtedness to the Chanute double-decker for our ideas regarding the best way of obtaining the strongest and lightest sustaining surfaces [wings].” Explaining their design in his sworn deposition for the 1920 Montgomery case, Orville testified that “it was apparent that the wings of a Chanute double-deck type [of glider] could be warped.”

Octave Chanute and his 1896 "double-decker" (as the Wrights called it)

Chapter 4: "Learning the Art of Airplane Design"

In this chapter, the book’s author, a history and arts major, attempts to explain key aerodynamic and stability and control aspects of aircraft design. Only major errors are discussed here. There are many others.

Page 65: At the bottom of the page he writes, “Although the record shows little specific discussion of these issues by the Wrights before 1901, it is clear….that they had at least a basic understanding of the reversal of the center of pressure before building their first full-size machine.” (Although he cites two references in the Notes section of his book for this statement, examination of the references reveals no justification for such a statement.)

On the next page he reverts to his favorite theme of Wright perfection, saying “Just as their initial instincts…regarding control moved them well ahead of their contemporaries, so too did their beginning assumptions concerning aerodynamics.”

Actually, both brothers recorded statements directly admitting that their canards (forward elevators) were the result of their erroneous concept of the movement of the center of pressure on a wing. During his speech in Chicago in 1901 Wilbur stated, “Our peculiar plan of control by forward surfaces instead of tails was based on the assumption that the center of pressure would continue to move farther and farther forward as the angle [of attack] became less”, an assumption that proved to be false. In his legal deposition of 1920, Orville recalled their perplexity thus: “Our elevator was placed in front of the surfaces [wings] with the idea of producing inherent stability fore and aft, which it should have done had the travel of the center of pressure been forward [with decreasing angle of attack] as we had been led to believe.”

The author admits that he couldn’t find much about the Wrights’ knowledge of center of pressure movements before 1901. The reason is that they didn’t know how it moved until the summer of 1901 when Chanute’s cohorts Edward Huffaker and Dr. George Spratt demonstrated it to them through wing balance tests at Kitty Hawk. Wright statements reveal that the reversal of movement of the center of pressure came as quite a surprise to them. Evidently they had only seen data on flat surfaces and neglected to check cambered ones.

                         Visitors to Kitty Hawk. l to r: Huffaker, Chanute, Wilbur Wright, and Spratt.

This is a good spot to address the constantly repeated claims throughout the book that the Wright’s “intuition” or “instinct” about aerodynamics enabled them to “visualize” air flow correctly in their minds without actually seeing it. This ability is credited for their development of their 1900 and 1901 wing shapes which he repeatedly claims were very good. He later contradicts these statements by blaming Otto Lilienthal’s data for these two vehicles having totally inadequate lift.

In fact, these vehicles could barely fly, and the Wrights’ wind tunnel showed them they had to change wing camber and aspect ratio to something very similar to Lilienthal’s (and numerous other predecessors) which solved their lifting problems. In a November 24^th, 1901 (i can't find this letter) letter to Octave Chanute, Wilbur admitted that “It is very evident that a table based on one aspect [ratio] and [wing section] profile is worthless for a surface of different aspect and curvature. This no doubt explains why we have had so much trouble figuring all our machines from Lilienthal’s table.”

Other examples of the Wrights’ “instinct” for aerodynamics failing them, but not noted in this book, were not seeing

• How cambered wings generate lift.
• That an airplane needs tails to be easily controllable.
• How wing warping would work in free flight.
• That a fixed vertical tail wouldn't stop their warp-induced spins.
• That stability and insensitivity to crosswinds were opposing goals.

Page 66: We are informed that when the center of pressure and center of gravity coincide, an airplane is at equilibrium. Instantaneously, yes. But practically, equilibrium implies stability at that point, i.e., the airplane should want to stay there. That requirement is something that eluded the Wrights, and evidently also the author of the book being discussed.

Page 67: Here he states that Horatio F. Phillips’ 1884 airfoil shapes set the precedent for the Wrights’ early airfoils. One can only conclude that he has never seen Phillips’ airfoils because some of them look quite modern, and all had maximum cambers at least a third of the way back, as opposed to those of the Wrights in which maximum camber was located immediately behind the leading edges.

Horatio F. Phillips' patented airfoil shapes

The author goes on to incorrectly discuss camber as if it was only “the [maximum] depth of the curvature” as opposed to the entire curvature of the wing from leading to trailing edges, including the critical location of maximum camber.

Page 68: Again, reality is contradicted here by saying that the Wrights’ early wings, with maximum camber right behind the leading edges were a “marked improvement in aerodynamic efficiency over the….wing used by Lilienthal and others” and “it also provided much more lift than the wings used by contemporary glider experimenters.” (Here again a source in his Notes section of the book is referenced that has nothing to do with his claim.) Contradicting this on pages 154 and 155 the author admits that their 1900 and 1901 wings were terrible and the wind tunnel showed that they had to move maximum camber much farther back and increase aspect ratio (more than doubling it to Lilienthal’s value) to obtain reasonable lift for their 1902 glider.

Page 69: He attempts to explain the “Penaud” method of achieving longitudinal stability but gets it exactly backwards by saying Penaud set his horizontal tails at a positive angle of attack. His explanation of how this would work is incoherent since it can’t work. In fact, Penaud set them at negative angles of attack to balance out the centers of gravity which were placed ahead of the centers of lift to achieve dynamic stability. With this, if the aircraft pitched nose up, Penaud’s negative tails would have a less negative angle to the wind and push down less, allowing the forward center of gravity to pull the nose back down. If the aircraft was pitched nose down, the tails would have a more negative angle, push down harder, and bring the nose of the vehicle back up.

                     Penaud's "aeronautical machines:" helicopter, planophore, and ornithopter.

And by the way, this author, like most all others, erroneously credits Penaud with originating this method of achieving stability. Sir George Cayley reported on using it for his unmanned gliders in Nicholson’s Journal in 1809.

Later on this page the author reveals the falseness of his assertion on page 65 that the Wrights knew about the reversal of movement of the center of lift (pressure) when they started. He says here that they “designed their forward rudder [canard] as if they were dealing with a wing having the properties of a flat plate,” i.e., no reversal of travel of the center of lift with angle of attack.

Page 70: Here he says “the Wrights’ scheme of a moveable elevator to keep pace with a constantly roving center of pressure was fundamentally sound, and it has been the method for pitch control on virtually every airplane since.” Yet again ignorance of aircraft design, and even flying, is revealed by not knowing that airplanes, once the horizontal stabilizer is trimmed out, do not need any help from an elevator to maintain longitudinal balance. A proper understanding of the “Penaud” technique would have revealed why.

Page 71: The author states that a canard stalls before the main wings because of its smaller size and thus avoids stalling of the wings which he implies is a stabilizing effect. Thus, two mistakes for the price of one. First, nothing stalls because of its size. It would stall first because of lack of camber or higher angle of attack, but not because it was smaller. Also, their canard is what made the airplane unstable and caused it to depart from level flight in the first place. It was therefore destabilizing.

Page 75: It’s asserted here that the Wrights didn’t put a vertical tail on their gliders for the first couple years because “it would complicate matters unnecessarily.” No, they didn’t think one was necessary because they were only trying to fly straight, and their aerodynamic “instinct” didn’t tell them about wing warping creating asymmetric drag which yawed their airplane. That’s why a rudder was required; to maintain the original heading.

In fact, in his speech in Chicago in 1901 Wilbur erroneously stated that “tails, both vertical and horizontal,..…may with safety be eliminated.” He then proceeded to design their next machines with vertical tails.

Page 78: Here the author explains the lift and drag equations as though lift and drag coefficients are the same for all wing shapes. Actually, until November of 1901 the Wrights thought so too.

Page 81: The bizarre tutorial on aerodynamics and airplane design is wound up by again admiring the Wrights’ supposed ability to mentally visualize aerodynamics, which, as previously noted, was often wrong. 

Summary - Part I:

At this point the first four chapters of the book Visions of a Flying Machine have been discussed. Due to the length of this critique the remainder will be discussed in the second part appearing shortly in truthinaviationhistory. That part of the article will begin the discussion of Chapter 5 with a list of ten seldom noted, but well documented, significant contributions to the Wright effort by Octave Chanute, without which the brothers' achievement of success would have been problematic.