Wright Brothers – Invention Of The Airplane

Articles relating to the Wright Brothers’ invention of the airplane.

A hundred years ago (1901) the Wright Brothers were disappointed with the performance of their glider at Kitty Hawk. This glider had bigger wings containing more than double the area than the one they had flown a year before. They were expecting much better results. Instead they found a significant lack in lifting power.

Wilbur and Orville suspected that the aeronautical data that they had used in their calculations for lift were erroneous. The famous glider pioneer, Otto Lilienthal, considered as the most important aeronautical experimenter of the nineteenth century, had developed the data. The brothers decided to find out for themselves the validity of the data by building a wind tunnel and generating their own data.

Why Airplanes Fly

Gliders and airplanes need to produce an upward force called lift that overcomes weight created by gravity in order to fly.

Lift is created by the flow of air over a wing. In general there are two concepts of physics involved. One is Bernoulli’s Theorem developed by Daniel Bernoulli, an eighteenth century scientist. He discovered that as the velocity of a fluid (such as air) increases, its pressure decreases.

In the case of an airplane, the wing is shaped to force the air flowing over the upper surface of the wing to flow faster than the air flowing over the lower surface. The faster air on the top surface creates a pressure differential resulting in an upward force on the wing.

Another contribution to lift comes from the effect of Newton’s third law. Isaac Newton has been regarded for over 300 years as the founding exemplar of modern physical science. Newton’s Third Law states that for every action there is an equal and opposite reaction.

As air passes over a wing, it is bent down. The bending of the air creates a downward force whose opposite equal force creates lift.

Determinants of Lift

There are a number of variables associated with creating and measuring lift. These include the size of the wing, the velocity of the air flowing over the wing, the density of the surrounding air, the shape of the wing and the angle of attack.

Area: All other things being equal, the larger the area of the wing, the more lift that will be created.

Wing Velocity: The higher the velocity the greater the lift. When an airplane is taking off, it normally heads into the wind because that increases the relative wind speed over the wings and helps the airplane reach flying speed.

Air Density: Air density refers to the amount of air contained in a given volume. Air density varies with the air’s temperature and pressure.

Decrease temperature and density increases. Increase pressure and density increases. Air is denser at sea level than it is at higher elevations.

The denser the air, the greater the lift. The air pressure at Kitty Hawk, being at sea level, is denser than the air at Dayton, Ohio. The temperature at Kitty Hawk on the day of the first flight was a cold 34 degrees. The Kitty Hawk Flyer may not have gotten off the ground in Dayton’s less dense air.

Coefficient of Lift: The coefficient is a multiplying factor that takes into consideration the various angles a wing assumes with regard to the flow of air. The value of the coefficient varies with the size of the wing and the “angle of attack.”

The angle of attack is the angle of the wing with relation to the wind flow. Raising and lowering the nose of an airplane while flying varies the angle of attack. Within limits, a greater angle of attack results in greater lift.

Raising the nose to an extreme angle of attack can result in loss of efficient airflow over the wing and result in loss of lift. This is called a stall and is a potentially dangerous condition.

Lilienthal is one of a number of early experimenters that were killed when their gliders went into a stall condition. While gliding in 1896 at an elevation of 50 feet, a gust of wind caught his glider causing it to nose up sharply. He was not able to correct the problem by shifting his weight and crashed. That accident was fatal for Lilienthal who received a broken spin.

Lilienthal in the Pocket Book of Aeronautics published a table containing coefficients of lift in 1895. They later appeared in The Aeronautical Annual and other sources available to the Wrights.

Smeaton’s Coefficient: Also involved in the calculation of lift at the time of the Wright Brothers was a constant number known as the “coefficient of air pressure.” It is a multiplying factor used to calculate the numerical value of lift in air, as compared to other mediums, such as water or oil.

John Smeaton, a mideighteenth century engineer, had determined the value of this coefficient was 0.005 in 1759, from his study of windmills. Engineers used the value of 0.005 for 150 years. The Wrights would subsequently find that this number was the major cause of their lift problem with their early gliders.

Modern aeronautical engineers no longer use Smeaton’s coefficient. Many have never even heard of it.

Camber: A barn door can fly, but not very well. A wing with a cambered shape is more efficient; that is, one that has a degree of curvature of the upper surface.

The Wrights tested over 200 airfoils to find the optimum shape in a 6-foot pioneering wing tunnel they designed and built. Airfoil number 12 was found to be the most efficient and was the model for the wing used on their successful first flight in 1903.

The Wind Tunnel

The Wright Brothers did not invent the wind tunnel, but they were the first to use it for scientific aeronautical research directly related to the design and construction of an airplane. There were ten wind tunnels in the world at the time and the Wrights was the third in the U.S.

Their wind tunnel was not elegant; at a glance it looked like a coffin. But it was in fact an elegant scientific instrument that would set the standard for conducting aeronautical research up to the present time.

The tunnel was a simple wooden box six feet long and sixteen inches square. It had a glass window in the top for viewing the measuring instrument they had designed. A one horsepower engine they used in their shop drove a fan that generated a wind of thirty miles per hour. It turned out that the wind generated in the wind tunnel was almost the same as the wind the Wright Flyer faced at Kitty Hawk on the first successful flight (27-mph).

They fitted a honeycomb grid on the fan end of the tunnel, which produced a perfectly straight current of wind required for accurate measurements. This gave them their biggest problem and took them a month to solve.

Their engineering expertise was demonstrated in the instrument that they devised to measure lift. It consisted of an ingenious mechanical balance device in which the test wing foil was compared to flat plates placed perpendicular to the wind flow. The coefficient of lift could be read directly from the instrument.

The completed wind tunnel was capable of testing a wide range of shapes and curvatures to an accuracy of 2-3%. Lilienthal, in contrast, tested and published data on only one specific curvature.

Found a Significant Error

The wind tunnel tests conducted by the Wrights proved that Smeaton’s coefficient of air pressure was in error. The Wrights’ discovered that the correct average value for this coefficient was 0.0033 rather than Smeaton’s 0.005 they had used in designing the 1900 and 1901 gliders. This error was the primary cause of their poor performance. Using the Smeaton value of 0.005 had caused them to overestimate the force of lift in their design by 40%.

They also found an error in Lillenthal’s lift coefficients, but it was a minor error within the angles of attack they would be flying. There was close coincidental correlation between the Wrights’ and Lilienthal’s coefficients between five and eight degrees of attack.

The Wrights had for the first time in history established a scientific basis for designing an airplane that would perform in accordance with prior calculations. Previous experimenters had relied on guesswork using trial and error. The Wrights relied on facts and figures. They now knew how to design a wing in which they could have confidence that it would fly.

On December 7, 1901, their sister Katharine wrote to their father:

“…The boys have finished their tables of the action of the wind on various surfaces, or rather they have finished their experiments. As soon as the results are put in tables, they will begin work for next season’s bicycles …”

New Design

In 1902, the year that “animal crackers” were introduced to America’s children, they returned to Kitty Hawk with a new glider. Its design incorporated all their wind tunnel data. The wingspan was now 32 feet, ten feet longer than the 1901 glider with a longer and narrower shape with a camber of 1 to 20.

The wing area of 305 square feet was only slightly bigger than the 290 square feet of their previous year’s glider, yet it generated much greater lift.

Their experiments enabled them to select a new wing shape with an efficient lift-to-drag ratio. Drag refers to the resistance that the wing generates as it flows through the air. The most efficient wings are those that generate the least drag for the most lift.

Their data demonstrated that longer, narrower wings in general produce more lift than the same area contained in short, wide ones.

Their data also showed that a parabolic wing camber with the high point toward the front was more efficient than the perfect arcs that Lilienthal and others had used.

The camber they used on the 1902 glider was a relatively flat 1 in 24 to 1 in 30 depending upon how the wing was rigged. This specific wing configuration was never actually tested in their wind tunnel. They apparently extrapolated this configuration from their other data.

All of the above were new and original conclusions resulting from their wind tunnel experiments. The Wrights’ were now far ahead of anyone else in the aeronautical field.

World Record Flights

They flew their new glider somewhere between 700 and 1,000 times during their five weeks of experimenting at Kitty Hawk. On October 23, Wilbur sailed 622 1/2 feet in 26 seconds setting new American records.

“We now hold all the records! The largest machine we handled in any kind of weather, made the longest glide, the longest time in the air, the smallest angle of descent and the highest!!!”

They were now convinced that the data they had found from their wind tunnel tests would enable them to calculate in advance the performance of their first powered airplane. They had mastered two of the three conditions of flight. They had designed wings capable of sustaining flight and developed a three-axis control system that allowed maintaining balance and executing turns. The next step was to develop an engine and propeller.

Calculation of lift for the 1903 Kitty Hawk Flyer

The formula used to calculate lift is as follows:

L = kxV²xSxCL where

L = Lift (pounds)
k = Smeaton’s coefficient
V = Relative Velocity of air over wing (mph)
S = Wing area (square feet)
CL = Coefficient of lift

k = 0.0033 (from Wrights’ wind tunnel experiments)

V = 33.8 (wind of 27 mph on December 17, 1903 plus ground speed of Flyer of 6.8 mph)

S = 512 (wing area of 1903 Flyer)

CL = 0.515 (from Wrights’ table of lift coefficients assuming airfoil #12 and an angle of attack of 5 degrees)

Substituting the approximate values for the 1903 Wright Flyer on the first flight:

L = (0.0033) x (33.8)² x (512) x (0.515) = 994 pounds

The weight of the Flyer, including engine was 605 pounds. Orville weighed approximately 145 pounds. Therefore, the total weight of machine plus pilot is 750 pounds

Since lift (994 pounds) is greater than the weight of the machine (750 pounds), the lift was sufficient to support flight.

The following is a talk that Tom Crouch gave on August 19, 2007. Crouch is senior curator of aeronautics at the National Air and Space Museum of the Smithsonian Institution and author of “The Bishop Boys” and other books. The talk took place during the morning in the Pavilion auditorium at the Wright Brothers National Memorial, Kill Devil Hills.

Crouch: Today, August 19, 2007 is a special day. It is Orville Wright’s birthday. It is also since 1938, National Aviation Day as well. And to really top it off, it is Katharine Wright’s birthday. Orville Wright and his sister, who is three years younger than Orville, were born on the same day. If Orville were alive today he would be 136 years old.

Orville was half of the team who invented the airplane. Wilbur was four years older than Orville. They lived in Dayton, Ohio where I was born. Their father was a bishop in a church and had an extraordinary impact on their lives.

When I wrote a biography of the Wright brothers, I called it, “The Bishop Boys,” to honor their father. Their mother was extraordinary as well. The Bishop couldn’t pound a nail straight; he wasn’t a very mechanical guy. Their mother was interested in mathematics and science and grew up in her father’s carriage shop and developed suburb mechanical skills.

Both parents contributed enormously to the invention of the airplane. They had great parenting skills and techniques. They were the kind of parents that did everything they could to encourage the curiosity of their children. They tried to answer the questions that the kids had and encouraged them to conduct their own experiments to get answers to their questions and it gave them enormous self confidence in their own capacity to do things.

One of the most extraordinary things about the Wright brothers psychologically, without which they never would have invented the airplane, was this extraordinary intellectual self-confidence that they had. These were two guys who had not gone to college and yet they were absolutely sure that when they conducted a piece of work they could trust the answer. So, they had that going for them.

Wilbur and Orville were close to one another. They had often said that growing up they had shared lots of things together such as their toys and ideas. They had played together and conducted experiments together and all that. Again, that is something else they had going for them.

I think that if they hadn’t been as close as they were, the two of them, they might not have been able to do what they did as single individuals. When it comes to the Wright brothers the whole was a whole lot greater than the sum of the parts. Together they were a pretty extraordinary team.

But they had distances too. Wilbur, for example, cared very little about personal appearance and that sort of thing.

Orville on the other hand was very much interested in all of that. He was the snappiest dresser in the family. To such an extent that when Wilbur went off in November 1901 to give the biggest speech of their lives, one of the most important speeches in the entire history of aeronautics, he went wearing his brother’s suit because Kate, their sister, recognized that Orville’s suit was in better shape and a lot better looking than Wilbur’s best outfit. So Wilbur gave his speech in Orville’s suit, shirt and tie.

Why did they go to Kitty Hawk? Why didn’t they do what they were going to do in Dayton? The answer is that Dayton is not a very windy place.

When the Wright brothers first became interested in flight, the first thing they did was to really take a look at the literature of flight that existed at that time. These guys were not college graduates, but at the same time, they were engineers of absolute genius. And they started out exactly the right way by reading what other people had written about flight.

As they drew some conclusions out of that reading, it was Wilbur who said, “look you can reduce this problem to three basic systems. If you are going to invent an airplane you have to have wings that are going to generate lift, you got to have a propulsion system that will move the wings through the air and you got to have a way to control the wings once you’re in the air. Lift, aerodynamics, propulsion and control – that’s it.”

As they looked around they recognized that people had learned something about wing design, for example. Not as much as the Wright brothers had originally thought they had, but at least enough to give them a starting point. And from the looks of what other experimenters had done with wings. They saw that they could actually calculate the amount of lift that a given wing design would generate in a wind of a particular speed.

When they ran the numbers they discovered that you were either going to have to build a pretty huge machine or you were going to have to fly in a pretty substantial steady headwind. They couldn’t find that kind of headwind in Dayton.

So they wrote to the U.S. Weather Bureau which kindly sent them weather statements with average winds at all the weather stations from coast to coast in the United States. It turned out that the windiest places actually were, as you might expect, cities on lakes. Places like Chicago and Buffalo, New York and places like that.

The Wright brothers didn’t want to conduct their experiments in urban areas. They really wanted to do this sort of on their own away from prying eyes and newspaper reporters and that kind of thing. So they went down the list. The first really rural isolated place on the list was Kitty Hawk, NC.

Where we are sitting now at the memorial is not Kitty Hawk, rather it is Kill Devil Hill. Kitty Hawk is located some four miles north of here. That is where the weather station was also located. And so when the Wright brothers found out about this windy little place on the isolated outer banks of NC, they wrote a guy named Joe Dosher who was running the weather station at that point and the only employee of the weather service at that time.

Dosher sent a short note back to the Wrights, but he recognized there were probably people in the village who were better than him to explain what this place was like to the Wright brothers than him. He turned Wilbur’s letter over to Bill Tate. Tate’s wife was the postmaster of Kitty Hawk. Bill had been the postmaster of Kitty Hawk, but his wife was doing it at the time.

Bill Tate wrote the brothers a very long and wonderful letter back talking about the fact that yes, if you guys want winds to fly into, we have dunes that you could conduct your experiments from and there are not a lot of trees that you can run into. The letter was just enough to let the Wright brothers know that in fact this was going to be a pretty good place to come.

But I think the clincher was that at the end of the letter Tate said something like “if you come down here, I can promise you one thing, you will find friendly people who will do what they can to extend a hand and help you with your experiments.”

I’m pretty sure that is what sold the Wright brothers on Kitty Hawk.

Wilbur set out for Kitty Hawk by himself. They had mostly prefabricated the glider in Dayton. So he set out on what was the greatest adventure of his life.

These guys were middleclass small businessmen from Dayton, Ohio. They had gone to the Chicago World’s Fair, but they really weren’t great travelers. So this really was an adventure for Wilbur Wright.

He set out from Dayton on a Big Four train for Cincinnati. In Cincinnati he changed to a B &O train which came all the way down the Ohio River, cut down across West Virginia, down through Virginia, passed Charlottesville, Gordonsville, and all the way down to Hampton Roads.

At Hampton Roads he had to get all his stuff on a steamer that would take him across Hampton Roads. He could catch the Southern Railroad train on the other side of Hampton Roads that would take him on down to Elizabeth City, where he had to buy some of the additional things he needed for the glider.

When he got to Elizabeth City, that was the end of the line. He had no idea how to get out here to Kitty Hawk. He had to go down to the docks and ask around for a guide who was willing to take him and his equipment across Albermarle Sound. He sailed on a leaky old sailboat into Kitty Hawk Bay spent the night on the boat anchored just off shore. The next morning he came ashore with all of his stuff.

Orville came down a little bit later that year. Wilbur told him it was a good place and I’m working on the glider. So Orville comes down.

They flew three gliders at Kitty Hawk — 1900, 1901, and 1902. The 1900 season was a little disappointing. They discovered that the glider they had designed so carefully didn’t generate as much lift as they had calculated it was going to.

They didn’t give up. They went back to Dayton. They decided there is some kind of a puzzle here; we will just build a bigger glider.

They came back to Kitty Hawk the next year, 1901, with a bigger glider and that was the first time they could really make genuine flights.

It was also the first time they got really scared. Now for the first time they were actually in the air and they discovered that although they had a pretty good notion of control, they could now recognize that they didn’t really have a good handle on control.

And once more this airplane was still not generating as much lift as their calculations had predicted. This meant that other people hadn’t known as much about wings as the Wright brothers had hoped they had.

So, they went back to Dayton and conducted some wind tunnel tests and came back with the 1902 glider in 1902. All the 1902 glider flights were made right outside here where the memorial now stands. There were actually four Kill Devil hills around here at the time, some of which were actually just small humps.

The 1902 flights were the first time that they had the feeling that they were home free. Now they had a machine that pretty much performed as predicted and was controllable, fairly so anyway. So they were ready to go ahead with the design of a powered flying machine, which they did.

And of course on December 17, 1903 at the base of the big Kill Devil Hill, their machine flew. They only made four flights that morning. Orville, whose birthday is today, made the first one

They took turns – Orville – Wilbur – Orville – Wilbur.

Orville’s first flight wasn’t all that much to write home to mother about – only about 120 feet, 12 seconds. But each flight was better than the one before it. By the fourth flight Wilbur was really beginning to get the hang of the thing. He flew almost 900 feet down the beach in the direction of Kitty Hawk. He was in the air almost a minute — 59 seconds.

Again, there were control issues, but he recognized that they were getting a handle on those.

He made a hard landing at the end of that fourth flight and they had to bring the airplane back down to the hanger. They reckoned that it was going to take a couple of days to perform the repairs on it. It was cold that day and they went into the shed to warm their hands up, and to make a long story short, a wind came up, tumbled the airplane, and when that episode was over, the world’s first airplane was sort of broken sticks, snapped wire, and torn fabric. They decided to take the pieces back to Dayton.

That’s why the world’s first airplane in our museum in Washington D.C. only made four flights, those four between 10:35 and noon on Dec 17, 1903.

That’s a little something about the guy whose work we are celebrating today and his brother. And I always include their sister too.

There have always been sort of epochal stories about the extent to which Katharine, who was a schoolteacher in Dayton and the only college graduate in that generation of the family, gave money to her brothers or helped them with higher mathematics. None of that is true. They did all of that on their own.

All the money that they spent coming down here, camping out, building the airplanes, testing them, all of that came out of the bicycle shop. Everything they needed to know to build that airplane – the mathematical base that they needed, the reading they had to do — that was all them. Kate had nothing to do with any of that.

On the other hand, I argue that if it hadn’t been for her, they might not have done what they did at all. Kate gave them a home. Neither of them ever married. They lived in their father’s home and Katharine Wright made that a home for them. After teaching at a high school all day in Dayton, she would supervise the cooks and the people that cleaned the house, and that kind of thing, and made it a home for all of them, for the Bishop as well as Wilbur and Orville.

And she was also the glue that sort of kept the family together. If you doubt that all you have to do is read Orville and Katharine Wright’s letters back and forth to one and the other. They’re wonderful letters. A friend of mine, a guy with whom I have been coming down here for 25 years, and I are editing a final volume of the Wright letters written between 1907 and the time of Wilbur’s death in 1912. We are bringing the project to an end that the original editor of the papers of Wilbur and Orville Wright always wanted to do.

But when you read those letters and again the unpublished ones too. It just comes home to you what wonderful writers and warm human beings made up this family, the extent to which they cared about one another, supported one another, and just really did their best to support one another.

So those are the two people, Orville and Kate, whose birthday we are celebrating today and its National Aviation Day too as I said. So actually we are celebrating the whole thing.

The Wright Brothers would never have won the race to fly a power-driven airplane if success had depended on money. While their American and European competition depended on large amounts of money contributed by government or other benefactors, the Wright Brothers relied solely on their own modest financial resources.

Frugal Brothers

During the five years of experiments from 1899 to 1903 the Wright Brothers, without any outside financial support, spent a grand total of under $1200.00. Their expenses included the construction of a large kite, three gliders, and one power-driven airplane. The money also covered the expenses of four extended trips to Kitty Hawk.

Their record of expenses includes such things as $5.50 for books on aviation in June 1899, train tickets to North Carolina for $22.50, $25 to build the 1900 glider and a $15 fee to the U.S. Patent Office in 1903.

Langley Fails

In contrast, their biggest competitor, Samuel Pierpont Langley, Director of the Smithsonian Institution, was awarded a $50,000 contract by the U.S. War Department, supplemented by a $20,000 grant from the Smithsonian, to build a power-driven airplane. Langley’s airplane failed dismally. It twice crashed into the Potomac River after being catapulted from a houseboat. The last failed attempt occurred only nine days before the first successful flight by the Wright Brothers. One reporter said Langley’s Aerodrome had the flying characteristics of a “handful of mortar.” The failure was bitterly disappointing to Langley who had devoted 17 years of his life to the development of an airplane. It had taken the Wrights only three and a half years of work to the first flight.

Wright Cycle Company

The Wrights financed their flight ambitions from the modest profits of their small business. The introduction of the safety bicycle (two wheels of the same size) had launched an industry that was experiencing phenomenal growth. In 1892, the brothers saw the opportunity to start a bicycle shop, the Wright Cycle Company, to supplement their printing business. It wasn’t long before the prospering cycle shop was their primary business selling brand name bicycles, parts, accessories and repairs.

Starting in 1896, they decided to manufacture their own brand of bicycles. The top of the line was the Van Cleve. This model initially sold for $60 to $65. By 1901 it was selling for $39.50. They also sold a lower-priced model, the St. Clair. It initially sold for $42.50. In addition, they sold bike tires for $3 and inner tubes for $1.25. These prices seem low by today’s standards, but in 1900 the average annual wage of a worker was only $440.

They hand-built their cycles to customer order to insure the highest quality. They contained a unique oil-retaining hub and coaster brake of their own design. Every bike was brush painted with five coats of paint.

The Wrights’ income was around $2,000 to $3,000 a year, most of which resulted from their bicycle business.

The Wright Brothers learned to be frugal from their boyhood years. Their family, while not poor, wasn’t flush in money either. Their father was a church Bishop and their mother stayed home to raise five children. The boys were required to earn their spending money. They collected scrap iron, organized their own circus, made their own toys, built and sold kites and built their own printing press.

Inventing on a Shoestring

Being frugal was an asset in solving the problem of flight. They had to use their brains to find a solution since they couldn’t afford the “trial and error” approach. They had a low threshold for guesswork. Instead, they were avid practitioners of the scientific approach that they used to cut to the heart of problems. They developed their own theories and meticulous calculations and applied them to design, build and test their ideas using low cost kites and gliders.

They developed the 3-axis control system of flight, made small airfoils out of brass blades and tested them in a wing tunnel they designed and built in order to determine the proper shape of a wing to provide optimum lift.

They designed the airplane, weighing 605 pounds, of lightweight materials enabling them use a small gasoline engine. With the help of their only employee, Charlie Taylor, they designed and built a 170-pound engine with accessories that produced 12 horsepower.

They developed original theory of airplane propeller design and hand made them to deliver optimum thrust effectively and efficiently.

Langley’s engine could develop 52 horsepower but his Aerodrome was unstable, uncontrollable and underpowered.

Price Inflation

In preparation for the 100th anniversary of the first flight on December 17, 2003, a reproduction of the Wright Flyer is currently being built to fly at Kitty Hawk on the anniversary. It is estimated that the cost of the reproduction will exceed $2-million.

As I am writing this article, there are new airframe components for a Wright Brothers’ airplane for sale on Ebay. First bid is for $25,000.

The Wright Brothers accomplishment was probably the greatest bargain in the history of mankind.

The dedication of Wright Field in 1927 presented a 5,000-acre site to the government on behalf of the citizens of Dayton. Some 600 citizens and business donated to the fund.

Orville Wright was present for the ceremony and contributed an article he wrote for the publication, “Aviation Progress,” that described the early trials of inventing the airplane. “Aviation Progress” dated October 8, 1927, was a special edition covering the dedication. It was published by the National Cash Register Co. (NCR).

Here is Orville’s story:

Our interest in aeronautics dates back as far as 1899, at which time my brother, Wilbur, and I started work on the development of a heavier-than-air machine which would be sufficiently mobile to permit practical flying.

Some of our experiments were carried out in Dayton and others in Kitty Hawk, NC.

The first actual heavier-than-air machine was a glider, flown in the year 1900, at Kitty Hawk. The span of this plane was 18-feet with a chord of 5-feet.

Most of the experiments with this glider were made as a kite, operating the levers by chords from the ground.

In 1903, we developed a power machine having a span of 41-feet and a chord of 6 1/2-feet. Inasmuch as we had previously been unable to secure a satisfactory motor for this plane, we developed and made one which met the requirements and which developed from 10 to 12 horsepower. The motor was a horizontal type.

The weight of the machine with operator was 750 pounds. This machine made the first flight in the history of the world at Kitty Hawk on December 17, 1903.

The flights of 1902 glider had demonstrated the efficiency of our system of maintaining equilibrium, and also the accuracy of the laboratory work upon which the design of the glider was based.

We then felt we were prepared to calculate in advance the performance with a degree of accuracy that had never been possible with data and tables possessed by our predecessors. Before leaving camp in 1902, we were already at work on the general design of a new machine which we proposed to propel with a motor.

When the motor was completed and tested, we found that it would develop 16- horsepower for a few seconds, but that the power rapidly dropped till, at the end of a minute, it was 12-horsepower. Ignorant of what a motor of this size ought to develop, we were greatly pleased with the performance.

More experience showed us that we did get one-half of the power we should have had.

We left Dayton, September 23rd, and arrived at our camp at Kill Devil Hill on Friday, the 25th.

On November 28, while giving the motor a run indoors, we thought we again saw something wrong with one of the propeller shafts. On stopping the motor we discovered that one of the tubular shafts had cracked. Immediate preparation was made for returning to Dayton to build another set of shafts.

Wilbur remained in camp while I went to get new shafts. I did not get back to camp again till Friday the 11th of December.

Saturday afternoon the machine was again ready for trial, but the wind was so light a start could not be made from level ground with the run of 60-feet permitted by our monorail track. Nor was there enough time before dark to take the machine to one of the hills where, by placing the track on a steep incline, sufficient speed could be secured in calm air.

Monday, December 14, was a beautiful day, but there was not enough wind to enable a start to be made from the level ground around camp. We therefore decided to attempt a flight from the side of Kill Devil Hill.

We arranged with the members of the Kill Devil Hill life-saving station, which was located a little over a mile from our camp, to inform them when we were ready to make the first trial of the machine.

During the night of December 16, 1903, a strong wind blew from the north. When we arose on the morning of the 17th, the puddles of water, which had been standing about the camp since the recent rains, were covered with ice. The wind had a velocity of 10 to 12 meters per second (22 to 27-miles per hour). We thought it would die down before long and so remained indoors the early part of the morning.

But when ten o’clock arrived, and the wind was as brisk as ever, we decided that we had better get the machine out and attempt a flight.

We hung out the signal for the men of the life-saving station. We thought by facing the machine into a strong wind there ought to be no trouble in launching it from the level ground about the camp.

We realized the difficulties of flying in so high a wind, but estimated that the added dangers in flight would be partly compensated for by the slower speed in landing.

After running the motor a few minutes to heat it up, I released the wire that held the machine to the track, and the machine started forward into the wind. Wilbur ran at the side of the machine, holding the wing to balance it on the track. Unlike the start on the 14th, made in calm, the machine facing 27-mile an hour wind started very slowly. Wilbur was able to stay with it until it lifted from the track after a 40-foot run.

One of the life-saving men snapped the camera for us, taking a picture just as the machine reached the end of the track and had risen to a height of about 2-feet.

The course of the flight up and down was exceedingly erratic, partly due to the irregularity of the air, and partly to lack of experience in handling the machine.

The control of the front rudder was difficult on account of its being balanced too near the center. This gave it a tendency to turn itself when started, so that it turned too far on one side and then too far on the other. As a result, the machine would rise suddenly 10-feet and then as suddenly dart for the ground.

A sudden dart a little over 100-feet from the end of the track, or a little over 120-feet from the point at which it rose into the air, ended the flight.

As the velocity of the wind was over 35-feet per second and the speed of the machine over the ground against this wind 10-feet per second, the speed of the machine relative to the air was over 45-feet per second (30.7 mph), and the length of the flight was equivalent of a flight of 450-feet made in calm air.

This flight only lasted 12-seconds had but it was nevertheless the first time in history of the world in which a machine carrying a man raised itself by its own power into the air in full flight, had sailed forward without reduction of speed, and had finally landed as high as that from which it started.

At twenty minutes after eleven Wilbur started on the second flight. The course of this flight was much like that of the first flight, very much up and down. The speed over the ground was somewhat faster than of the first flight, due to the lesser wind. The duration of the flight was less than a second longer than the first, but the distance was about 75-feet greater.

Twenty minutes later the third flight started. This one was steadier than the first one an hour before. I was proceeding along pretty well when a sudden gust from the right lifted the machine up 12 to 15 feet and turned it up sidewise in an alarming manner. It began a lively sliding off to the left. I warped the wing to try to recover lateral balance, and at the same time pointed the machine down to reach the ground as quickly as possible.

The lateral control was more effective than I had imagined, and before I reached the ground the right wing was lower than the left and struck first.

The time of the flight was 15-seconds and the distance over the ground was a little over 200-feet.

Wilbur started the fourth and last flight at just twelve o’clock. The first few hundred feet were up and down as before, but by the time 300-feet had been covered, the machine was under much better control. The course for the next four or five hundred feet had but little undulation. However, when at about 800-feet the machine began pitching again, and on one of its starts downward struck the ground.

The distance over the ground was measured and found to be 852-feet. The time of the flight was 59-seconds.

The frame supporting the front rudder was badly broken, but the main part of the machine was not injured at all.

There are three people that can speak with authority about the flying qualities of the Wright 1903 Flyer. They are Orville Wright, Wilbur Wright and Ken Kochersberger.

Who is Ken Kochersberger? Ken is a professor at the Rochester Institute of Technology, Rochester, NY. But more important to this article is that Ken is the only other person that has successfully flown the Wright 1903 Flyer.

Ken flew a reproduction Flyer on Nov. 20, 2003 at the Wright Memorial in Kill Devil Hills. It was launched in a northerly direction into a 12-mph wind and flew 97 feet. This is the first time in 100 years that a Wright 1903 Flyer has been successfully flown and landed without damage, using an authentic engine.

Ken flew another flight of 115 feet and landed sustaining minor damage to the Flyer consisting of four broken ribs.

Two other flights were attempted. One resulted in a crash. The final flight was attempted on Dec. 17, 2003 during the Wright brothers centennial celebration at Kill Devil Hills. Unfortunately the weather was not suitable to sustain a successful flight.

This reproduction Flyer was researched and built by Ken Hyde’s Wright Experience, Warrenton, Va. They produced an exact reproduction of the original machine, including the engine, using artifacts and photographs. This plane is more faithful than the “original” Flyer hanging in the Air and Space Museum in Washington, D.C.

The Wright brothers never flew their 1903 Flyer again after their fourth successful flight in 1903. The machine was caught by a gust of wind while resting on the ground and sent tumbling over the sand, which resulted in severe damage. The Wrights dissembled and packed the parts of the airplane in crates and sent them back to Dayton.

There, it sat in storage enduring flood damage in 1913. It was taken out of storage and restored in 1916 and again in 1925. On both occasions the restoration was for display and not for flying. This resulted in some subtle but significant variations of the original structure.

Here are some observations from a pilot’s perspective on flying the Wright Experience Flyer.

The Flyer is not very comfortable to fly. Elbows must be placed to avoid the fuel mixture control and the fuel line, creating an awkward position. One must lie on the wing in an arched shape for forward visibility, not a comfortable position for long periods of time. To gain some relief, the pilot can shift around in the wingwarping cradle during the engine start prior to launch.

During takeoff it is necessary to keep the wings levels because they are only two feet off the ground. The famous picture of the first flight shows Wilbur running along side the Flyer. He had been holding the wings steady until takeoff.

The canard (front elevator) is kept neutral to reduce drag while running down the launching rail until ready for rotation. A positive canard deflection of at least 10 degrees is required to initiate flight.

The Flyer benefited by the wings being close to the ground by increased lift, “ground effect,” and a reduction of “induced drag.” The anhedral (curved down) shape of the wings also produced additional lift.

There was no speed indicator on the Flyer, so the pilot must estimate the speed for rotation by experience. Once takeoff speed is reached, the Flyer requires significant positive canard to rotate because of a nose-down moment caused by the thrust line.

Rotation is limited to 3.5 degrees by the physical clearance between the tail and the rail. At this rotation the target speed is 26-mph.

Complicating the process is that the flyer trims with more canard at higher speeds and less with lower speeds. This requires the pilot to continuously adjust trim reference as airspeed changes. If there is a crosswind on takeoff, the warp corrections held on the rail must be lessened immediately at rotation.

Wingwarping was found to be responsive. The hip cradle required about 14 pounds of force. This is about twice that required on the 1902 glider. A good grip is required on the canard actuator crossbar while moving the hips to prevent the body from moving instead of the cradle.

The Flyer is unstable in sideslip during takeoff because of the anhedral of the wing. The flight on Dec. 3, 2003 experienced a crosswind and upon rotation the right warp and the anhedral effect caused a right roll with the right wingtip grazing the ground. The plane recovered and continued to fly and landed with the left wing low after traveling 115-feet.

Once the Flyer is airborne, large pitch corrections are required frequently to maintain stability. The wood structure of the Flyer is flexible which makes all control inputs less responsive resulting in control lags. The machine is substantially unstable in pitch and never flies strictly at trim but operates over the full range of the canard travel.

Ken reports that the Flyer flies more like a powered kite than an aircraft, with a soft feel to the handling in part caused by the lag between the canard input and the pitch response.

The Wright Experience pilots found that they could handle the Flyer although it takes much practice to acquire the flying skills needed. They all found a new respect for the skills and talent of Orville and Wilbur.

References: Flying Qualities of the Wright Flyer: From Simulation to Flight Test, Kochersberger, K., Ken Hyde, et. al., 42nd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, 5-8 Jan. 2004.