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 #1: The Wright Brothers

The Wrong Wright Story Series #1:

Fred Kelly's The Wright Brothers

A Critique by Joe Bullmer

 

This article, the first in a five-part series, addresses some of the discrepancies in Kelly’s 1943 book The Wright Brothers, (paperback reprint ISBN 0-486-26056-9) as compared to the Wrights’ original records and other well-established aviation history and scientific facts. Only his chapters IV through VIII are addressed since this material covers the period from 1899 through 1905 wherein the Wrights developed a powered controlled airplane (as discussed in chapters III and IV of my book, The WRight Story.)

On page 47 of the paperback edition of Kelly’s book, Orville gave him the impression that previous aviation experimenters such as Clément Ader, Hiram Maxim, Otto Lilienthal, Octave Chanute’s team and the Scottish experimenter Percy Pilcher had all accomplished very little. Actually, according to the French Aeronautical Society, Ader flew his first powered airplane smoothly for 165 feet (the length of his testing field) in 1890. Maxim’s powered vehicle, a result of his technical research, lifted off of its support rails for about 10 seconds and 400 feet in 1894. Lilienthal did over 2,000 controlled glides, some 1,000 feet long, during the mid-1890s, and Pilcher accomplished nearly 1,000 glides during the late 1890s.

From left to right: Clément Ader, Hiram Maxim, Octave Chanute, Otto Lilienthal, and Percy Pilcher.

In an 1895 letter, Pilcher warned of too much stability making a glider difficult to handle, something the Wrights are sometimes credited with discovering seven years later. In fact, Pilcher was creating an engine for powered flight in 1899 when he was killed attempting a gliding demonstration in foul weather to generate funds for his experiments. Lilienthal was also investigating power sources and more refined controls during the last couple years before he was killed.

By 1896, Octave Chanute’s group had accomplished around 1,500 glides. A member of his team of researchers, Augustus Herring, created a manned trussed biplane glider with smoothly cambered wings that was their most successful design. Its wing layout and structure were copied by the Wrights for their vehicles. 

In fact, in a letter written on December 21^st, 1909, 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.” On November 30^th, 1910, he penned, “we considered Chanute’s double-deck truss superior….and succeeded in adapting it to our own ideals and principles of control."  However, the Wrights failed to use Herring’s wing shapes, which set them back a couple years until their wind tunnel showed them that they had to adopt wing camber curvatures and aspect ratios (wing length to width) similar to those used on the Chanute/Herring and Lilienthal gliders.

But even more unfortunate for the Wrights, they failed to adopt the aft surfaces that the Chanute/Herring vehicle used for control of pitch and yaw. The need for such controls had been illustrated by Sir George Cayley in a 1799 engraving, and documented in his November 1809 article "On Aerial Navigation" in Nicholson’s Journal of Natural Philosophy, Chemistry, and the Arts. In it, he stated that an aircraft needed an “up-and-down” rudder in addition to a “side-to-side” rudder, both located behind the main lifting wings. This had also been recognized by aviation experimenters since Cayley, including Jean-Marie LeBris in the 1850s, Alphonse Penaud in the 1870s, and of course Herring and Langley in the 1890s. Many of these experiments were discussed and illustrated in Chanute’s 1894 book Progress in Flying Machines, which the Wrights obtained in 1899 prior to their experiments. 

Ignoring or overlooking these features caused the Wrights great difficulty in developing their aircraft and, by the time they discarded the forward elevator in 1910, they were hopelessly behind other aircraft designers.

Sir George Cayley and his 1799 engraved silver disc, the first drawing of an airplane.

Evidently, not having researched aviation developments prior to the Wrights, Kelly was not aware of any of this. But even more egregious, subsequent historians and authors either did not bother to research flight experiments that preceded the Wrights, or they chose not to tarnish the Wright image established by Kelly a half century earlier. Thus evolved the myth of Wright “genius” in developing the configuration of their aircraft. In fact, aircraft layouts rapidly evolved to more closely resemble mid-19^th century configurations of Cayley and LeBris than the early 20^th century Wright Flyers. In any case, the impression Orville gave Kelly that previous experimenters had accomplished next to nothing is patently false.

Before leaving Herring, it should be mentioned that in 1898 he created an airplane that he claimed made a short powered flight into a stiff headwind in October of that year. Unfortunately it was destroyed in a storage shed fire before it could demonstrate its full potential.

On page 49, Orville claims that no one before them had thought of warping or bending wing extremities for lateral control. Actually, warping had been employed by LeBris in 1857, Richard Hart in 1870, John Montgomery during the 1880s, Clément Ader in 1890, Pierre Mouillard in 1896, and even Lilienthal in 1896. In fact, LeBris, Ader, and Mouillard had patented it. These controls could either yaw or roll a vehicle depending upon their degree of deflection. Slight deflections would tend to roll a vehicle away from the downward warped wing, while large deflections would yaw and roll the machine into the downward warped wing due to its disproportionately large drag increase slowing it down, actually reducing its lift. 

This control reversal perplexed the Wrights for a couple years until they came up with the moveable rudder to resist the yaw and force the vehicle to hold its heading while the wing warping returned it to level flight. 

 

Patent drawings by (l to r) LeBris, Ader, and Mouillard.

So the Wrights created their aft rudder not to yaw or turn, but to continue flying straight when correcting inadvertent rolls. In spite of their having explained this many times, even in their patent (see page four, lines 16 to 45), everyone who discusses the Wrights and their work always assumes their coordinated rudder was created to turn. Perhaps their lawyer, Harry Toulmin, described it most clearly in an explanation to the patent examiner, William Townsend, for their patent application based on the 1902 glider. Toulmin wrote “….the vertical rudder is in no sense a steering device, but is simply for correcting the increased resistance offered by one end [side] of the machine over the other arising from the different angles at which the ends of the planes [wings] are presented to the wind, and this it does automatically.” In fact, the Wrights’ records show that they couldn’t reliably accomplish turns with their aircraft until they disconnected their rudder from warping in 1905.

On page 53, Orville takes credit for devising the canard or forward-mounted elevator configuration of their early vehicles. In reality, Wilbur was the major designer of their early gliders. In a 13 May, 1900 letter to Octave Chanute, Wilbur stated that the 1900 glider would have an aft elevator similar to the kite they had tested the year before. But Wilbur changed his mind, and since he fabricated the machine at Kitty Hawk before Orville even arrived, it is clear Orville had little, if anything, to do with its configuration. The Wrights came to value the ability of the canard elevator to prevent stalls and avoid post-stall dives. Actually, considering the pitch instability their forward-mounted elevators created until they were abandoned in 1910, it seems odd that Orville would want to claim credit for that feature.

On Kelly’s page 54, Orville claims that Wilbur was the one responsible for misunderstanding the movement of a cambered wing’s center of lift with varying angle of attack, resulting in their aircraft’s instability in pitch.

On that same page, Orville makes the false statement that a positively loaded canard (one generating an up force at normal flight angles) results in pitch stability, a mistake often repeated to this day. The argument usually cited is that when an aircraft with a positively loaded canard surface is pitched up, the canard’s greater angle of attack will tend to stall it before the main wing does, thus allowing the angle of attack to drop avoiding stall of the main wings. While generally true, that is not what stability is about. Stability is concerned with how well an airplane avoids such unintentional pitch excursions to begin with. With a higher angle of attack, a positively loaded canard pulls a slightly pitched up aircraft farther up and away from a stable level attitude and toward a stall. That is unstable.

Discussing their test site on the next page, no credit is given to Chanute for recommending the Carolina and Georgia coasts, with their sand dunes and winds, as being excellent for gliding experiments. He did so in a letter to Wilbur on May 17^th, 1900 while they were looking for a site.

Orville’s limited understanding, or perhaps recall, of technical issues is revealed in his discussion of the 1900 and 1901 vehicles’s glide performance on page 69. He blames the poor performance on improper maximum wing camber when in fact the poor performance was not due to the amount of maximum camber but rather to locating the maximum camber just aft of the wing’s leading edge with the rest of the wing flat or reflexed, and also to the low aspect ratio of the short stubby wings. Actually, maximum camber should occur from a third to halfway back in the wing, and aspect ratio should be at least twice what it was on those machines. Of course, Kelly could judge none of this.

The 1900 Wright Glider, designed primarily by Wilbur Wright.

Page 71 discusses the Wrights’ discovery of the true movements of their wings’ centers of pressure or lift without any mention of the fact that the visitors Chanute brought to Kitty Hawk, Dr. George Spratt and Edward Huffaker, had to inform the Wrights about it and suggest a test to prove it. The Wrights had thought that, just as on a flat plate, a cambered wing’s center of lift or pressure would gradually move from the leading edge to the midpoint as the angle of attack increased from zero to 90 degrees.

However, on a cambered wing, at the low angles of attack used in flight, the center of lift actually moves forward as the angle increases. This is due to the more angled curvature accelerating and thinning the flow sooner along the forward upper surface of the wing. Also, any flow separation area on the aft upper surface expands forward from the trailing edge of the wing as the angle of attack increases, destroying lift there. 

Photo from Octave Chanute's 1901 visit to Kitty Hawk. (l to r: Octave Chanute, Orville Wright, Edward Huffaker, Wilbur Wright.)

Finally, during testing at Kitty Hawk in 1901, Spratt and Huffaker talked the Wrights into separating one wing from their glider and determining where it would balance in pitch at various angles of attack. This is another thing Orville had to admit under oath in his 1920 legal deposition for the Montgomery patent infringement case. He testified that “Dr. Spratt and Mr. Huffaker both suggested that there might be a rearward travel of the center of pressure on the curved surfaces at the small angles of incidence [as the angle is reduced]”. But before that, in his September 18, 1901 speech to the Western Society of Engineers, Wilbur said that “While the machine was building, Messrs. Huffaker and Spratt had suggested we would find this reversal of the center of pressure”.

Kelly recounts on page 73 that, according to Orville, in this same 1901 speech, Wilbur blamed their gliders’ poor performance on errors in the Lilienthal pressure table they had used to design the vehicles. Orville added that at the time he was not so sure that Lilienthal’s data was in error. Actually, while Wilbur only expressed uncertainty about Lilienthal’s data in that speech, I found no contemporary record of any dissension or position on the matter by Orville.

Otto Lilienthal's Table of Normal & Tangential Pressures

Apparently, Orville didn’t tell Kelly that a couple months later their wind tunnel actually showed there weren’t any errors in Lilienthal’s data. In fact, the errors resulted from the Wrights' poor camber shapes and aspect ratios. Wilbur clearly admitted this in letters to Octave Chanute on November 24th, 1902, stating that “[Lilienthal’s data] table is probably as near correct as it is possible”, and another on December 1st, 1902, “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.”

On the following two pages, Orville claims to have designed and built their first and second wind tunnels himself, and to have designed the balances in the tunnels that yielded lift and drag data. In twelve years I have found no record to support this. What I have found is a letter Wilbur sent to Chanute on October 16th, 1901 mentioning the wind tunnel photos Chanute showed them at Kitty Hawk, stating “The wind from the fan is rendered uniform in direction by the same means [as] in the photographs you showed us at Kitty Hawk”. Orville finally explained under oath in his 1920 deposition that they had gotten the design of the lift vs drag force balance from Dr. Spratt, writing, “This utilized an idea which had been suggested by Dr. Spratt.” Clearly, their guests at Kitty Hawk had familiarized the Wrights with the designs of some of the ten wind tunnels that had been built previously.

Then, on page 76, Orville claims that with their tunnel, they “discovered” the significance of wing aspect ratio - the ratio of a wing’s width or chord to its length or span. They may have, but this had already been discovered a century earlier by Sir George Cayley as documented in his November, 1809 article in Nicolson’s Journal, and by numerous experimenters throughout the 19th century such as Maxim, Lilienthal, and Langley.

Cayley's gliders in which his assistant and coachman briefly flew.

Orville claims on the next page that “they were the first men in all the world” to compile wing design data with their tunnel that could be used to design an airplane. They were not the first. Other aviators had already compiled design data from their wind tunnels (Maxim, Zahm, Phillips, and Wenham), or by using whirling arm devices and natural winds (Lilienthal and Langley). In addition, Orville’s statement is misleading since, unlike many of their predecessors, the Wrights never published their data so it could be used for designing by anyone else.

On page 80, it’s claimed that the Wrights were the very first to know correct wing shapes by 1902. An incomplete list of experimenters that preceded the Wrights, and used camber and aspect ratio wing shapes far superior to those of the Wrights' 1900 and 1901 machines, includes George Cayley (1799), LeBris (1857), Wenham (1866), Penaud (1870), Goupil (1883), Phillips (1884), Montgomery (1885), Lilienthal (1889), Ader (1890), Langley (1890), Pilcher (1896), Herring (1896), and Whitehead (1901). All but a couple listed here actually created models or vehicles that flew. Most of this was covered in Chanute’s book, which the Wrights obtained in 1899.

l to r: Montgomery's 2nd Monoplane Glider; Langley's Aerodrome No. 5; Whitehead and his No. 21 aircraft

  On page 81, Orville takes complete credit for figuring out the problem caused by the fixed vertical tails on the 1902 glider, and figuring out the solution of a moveable rudder. But Kelly takes the discussion too far by claiming that the Wrights’ system of ailerons (actually warping) and rudder deflection is used today (today = 1943?). Furthermore, the following paragraph explains that the Wrights connected them to move together automatically, a system since used briefly in only a very few aircraft and discontinued due to safety concerns. Even the Wrights found that the controls had to be disconnected and used at different times and with different deflections. For example, when correcting a roll, less rudder deflection is required to hold a heading than is used to swing the airplane into a coordinated turn. In fact, on an airplane with dihedral, the controls for roll and yaw are cross-controlled (i.e., one is reversed) to side slip in a crosswind landing. 

The flight crew for the 1902 Wright glider, from left to right: Octave Chanute, Orville Wright, Wilbur Wright, George Spratt, Augustus Herring, and Dan Tate.

 

Orville says on page 84 that they doubted that an engine of 20 pounds per horsepower was available, but Wilbur wrote his father on September 23^rd, 1900 claiming that they would have no problem obtaining a suitable engine. Actually, engines of half that weight per horsepower existed at that time. It seems likely that the Wrights had their assistant Charlie Taylor build their engines simply because they didn’t want to spend the money for existing ones, particularly since they thought there was a good chance of destroying at least one of them in testing.

On page 89, Orville claims that they developed a better understanding of the proper design of a propeller than anyone else, but does not claim that they were the first to see the propeller as a spinning wing. The latter has been incorrectly implied or assumed, without research, by almost all historians and authors since Kelly. As reported in a previous article in this blog, in 1885 Sidney Hollands presented a paper to the Aeronautical Society of Great Britain explaining that a propeller should be cambered, twisted, and tapered toward the tips. This was reported in Chanute’s book, which, again, the Wrights had obtained in 1899. (Reverse taper, as used by the Wrights, puts unnecessary bending and twisting loads on the blades and exaggerates aerodynamic losses at the tips, much as reverse taper on wings would require heavier structure and degrade their efficiency.)

 

Page 101 presents the Wrights’ famous claim that on their fourth trial on December 17^th, 1903 their aircraft flew 852 feet in 59 seconds, a feat not verified by any witnesses or by photography. At least four different analyses have determined that the photo claimed by Orville to portray the end of the fourth flight shows the vehicle to be stopped less than 280 feet from the launch rail. For a detailed mathematical analysis of the photo see the November, 2019 article on this site.

Kelly, on page 128, appears to give total credit to the Wrights for the idea and design of the falling weight catapult first used in 1904, as have authors and historians since. In actuality, the idea and design were given to them in a July 29^th, 1902 letter from Chanute, who himself got the design from Albert Merrill, a New England gliding enthusiast. Chanute wrote “I have your letter of July 27^th and enclose a letter from Merrill and some photos”, and farther along, “Merrill had written to me to get my endorsement for…..a method for imparting initial velocity for a glider through a falling weight”.

Page 133 contains an interesting claim by Orville that, although they had to disconnect the rudder from wing warping in 1905 in order to make turns, they reconnected it “several years later”, albeit with a device to alter rudder deflection to enable both roll corrections and turns. I have never found any contemporary record of this, but if true, it must have been temporary and prompted by some opponent in a patent suit pointing out that testing forced them to abandon the very control scheme they patented and were defending in court. The technical limitations of a warp/rudder interconnect were explained in previous comments about Kelly’s page 81.

These are the major discrepancies in Chapters IV through VIII of Kelly’s 19-chapter book. They contradict information in Wright letters and records made from 1899 through 1905, the years from the Wrights first experiments through to the development of a controllable airplane. Many of these differences could be said to have been fabricated, or at least exaggerated, by Orville to glorify his contribution. Others might ascribe them to forty years of fading memory. However, many other details were accurately recounted, and there are other examples of Orville, after Wilbur’s passing, having claimed credit for things that are not supported by their contemporary records.

It is evident that using Kelly’s book as a basis, a narrative of the Wrights’ development of the airplane could end up quite different from that derived from the far larger mass of contemporary records along with such material as Orville’s 1908 article in The Century and his 1920 legal deposition. This would be particularly true if someone only vaguely familiar with the science were to fill in numerous blanks with assumptions. Unfortunately, that’s what has happened over the intervening three quarters of a century. This will become obvious in subsequent articles here discussing other books and the latest TV documentary.

In all fairness to Kelly, it should be pointed out that his book was published ten years before McFarland’s compilation of the actual Wright records. Without McFarland’s compilation, it would have taken years for Kelly to have fact checked Orville’s statements. And that’s if he had reason to suspect that Orville was sometimes spinning yarns. But the other books and program I will be reviewing do not have that excuse. These, and countless other books and documentaries, were created a half to two thirds of a century later and appear to be products of either poor research, technical inadequacy, or a desire to glorify the Wrights’ legacy.  

_____________________________________________________________________________________

 "The Wright Brothers A Biography by Fred C. Kelly, 1989, Dover Publications, Inc. 31 East 2nd Street Mineola, N.Y.11503

(First published by Harcourt, Brace and Company, New York, 1943 as The Wright Brothers: A Biography Authorized by Orville Wright)