Wright Brothers – The Kitty Hawk Years

Articles relating to the years the Wright Brothers spent at Kitty Hawk.

Roller Coaster Flight

by Dr. Richard Stimson

in The Kitty Hawk Years

When Wilbur made the first attempt to fly a powered machine on December 14, 1903, the Flyer rose in the air steeply to about fifteen feet, stalled and crashed into the sand. He blamed the crash on his unfamiliarity with the sensitive elevator control.

Forewarned, the four successful flights on December 17 were handled better but still resulted in roller coaster rides that could have flown farther if not for the sensitive elevator control.

This wasn’t the first time that they experienced problems using the elevator for pitch control. The elevator on their 1901 glider hardly worked at all. This was an unexpected result that they didn’t understand because they hadn’t experienced this problem with their previous year’s glider.

E. C. Huffaker and George Spratt, two of their visitors, suggested that the problem might be the reversal of the center-of-pressure on the wings. They had experienced similar problems in their own work.

The brothers didn’t think this was their problem because they were using a wing camber similar to what Otto Lilienthal had used successfully and they didn’t think he had run into this problem.

At this point in time the Wrights didn’t understand the true nature of the center-of- pressure on a curved wing and what was happening as the angle of attack changed.

Here is a brief explanation. When a flat surface is at right angles to a stream of air, the center of this pressure lies exactly at the center of the surface. As the angle of the surface is reduced (smaller angle of attack) the center-of-pressure moves forward toward the leading edge. It continues moving forward as the angle is reduced until the surface is parallel to the stream of air. The center-of-pressure is now directly against the leading edge.

The behavior of a curved surface operates differently. As the angle of attack decreases, the center-of-pressure moves towards the leading edge as before.

However, when the angle of attack nears zero, the center of pressure reverses and moves rearward on the surface. In the case of a cambered airplane wing, this movement of the center-of-pressure forces the rear of the wing upward and consequently the airplane into a sudden dive.

The Wrights decided to test the wing of their glider to determine what was happening. They removed the top wing of their glider and affixed two lines to the front edge. They flew the wing as a kite under a variety of wind conditions.

They observed that in light winds the wing pulled upward on the lines indicating that the center of pressure was in front of the center of gravity and the leading edge was forced upward.

In stronger winds the wings were forced down at a smaller angle of attack and pulled down on the lines. This demonstrated that the center of pressure had moved behind the center of gravity toward the trailing edge of the wing.

The brothers now knew that the control problem with the 1901 glider was caused by the sudden reversal of the center of pressure at low angles of attack. These sudden reversals required frequent movements of the forward elevator to maintain stability in pitch.

The back-and-forth center of pressure travel produces what is called a “pilot induced oscillation,” in which the pilot’s efforts to control pitch might actually make it worse.

Fortunately the Wrights had made the wings on the 1901 glider so that the camber could be easily adjusted. They reduced the camber from 1 in 12 to 1 in 19. The glider handled much better after the change.

The problem of pitch control returned in 1903. Part of the problem this time was that the elevator was hinged at its center. With this configuration, the airflow forced the elevator to sharply deflect on its own after only a small movement away from the neutral position. Once the oscillation started it was very difficult for the pilot to regain control of pitch, resulting in a roller coaster ride that ended with a premature crash into the sand.

The brothers had lengthened the lever that operated the elevator by four inches after Wilbur’s control problems on December 14th. It did provide 65% more leverage but it is doubtful that it did much good.

Despite their problems on December 17, 1903

George Spratt, a young physician from Coatesville, Pennsylvania, was a good friend of Wilbur and Orville Wright. He was interested in the possibility that man be able to fly from an early age and found a common field of interest with the Wrights. He was with the Wrights at Kitty Hawk during 1901, ’02 and ‘03.

They had a falling out in later years when Spratt claimed that the Wrights didn’t give him sufficient credit for technical suggestions he gave them. Twenty-one years after they met all communications ceased when Spratt, in a letter, called the Wrights “secretive, obstructive and lacking in vision and generosity.”

Spratt once wrote that he was fascinated by flying creatures since boyhood. “Flying has been the dream of my life. I never scared a bird up or saw a valley, but I longed to go with it and envied it.”

The Wrights found Spratt to be a kindred spirit that shared their interest in the study of aeronautics. He was congenial and liked to tell funny stories.

Unfortunately, Spratt had a tragic downside. He was prone to depression that seemed to grow worse with age. The Wrights called the affliction “the blues” and Wilbur on several occasions tried to pull him out of it.

Spratt had a scientific background, having graduated from medical school in 1894. Strangely, the 28-year-old soon after graduating gave up his medical practice, claiming it was too strenuous on his heart and took up farming, which would seem to be a more strenuous physical occupation.

Spratt began his involvement with the Wrights when, like Wilbur, Spratt wrote Octave Chanute seeking information on aeronautics and asked him for a critique on a paper he authored on the possibility of man-flight.

In his letter of 1898 to Chanute he said, “Being very much interested in flying machines and fully believing in their economical practicability, I have had my views on the subject type written and send you a copy. I wrote them down primarily that I might have clearer grounds for experimenting, but am getting discouraged accomplishing so little for various reasons, principally lack of sufficient funds. With the discouragement, boldness makes itself felt and I take this liberty of addressing you. The flying machine must come and it will soon come.

He continued, “Studying the subject principally from observation of birds, etc., in complete isolation from other interest, I am ignorant of the advance made. — Will you do me the favor of reading and criticizing the promises and conclusion? I will surely count it as a favor. Am I on the line of thought generally accepted as correct? How can I keep in touch with the advances made? I want to know more,  I want to do more.”

Spratt shared with Chanute that he was studying the movement of the center of pressure on a curved surface and had designed an apparatus for measuring the lift on airfoils.

Chanute was impressed with his interest and activity and encouraged Spratt to continue his study. He further suggested that Spratt devise methods of testing the lift and movement of the center of pressure on a cambered wing.

Chanute backed-up his encouragement with an offer to pay his expenses for his experiments, including the construction of a full-scale glider.

Even though Spratt had said that he had accomplished little because of insufficient funds, he refused the offer of money because he thought he would “bungle” the job. Apparently Spratt had little confidence in his own ability to actually construct something.

On June 26 and 27, 1901 Chanute visited the Wrights in Dayton where they had a good conversation on what the Wrights were doing and the state of aeronautics in general.

As a result of the visit, Chanute decided that he would provide as much support for the Wrights as he could.

Chanute believed that the complex problem of flight could best be solved through a team approach. Several days after their meeting in Dayton he wrote to the Wrights, offering to send two assistants at his expense to Kitty Hawk for their 1901 test flights. The Wrights didn’t want nor need any help, but didn’t wish to offend Chanute so they accepted his offer but not on the basis of the assistants working for them.

Edward Huffaker, who had worked for Samuel Langley and Spratt, were the two assistants.

The Wrights brought with them to Kitty Hawk the largest glider ever made. They hoped to have solved the previous year’s (1900) problem of inadequate lift. Spratt arrived for his first meeting with the Wrights on July 25, 1901.

While watching the Wrights assemble their glider, both Huffaker and Spratt warned the Wrights that they might encounter a pitching problem during flight because of a phenomenon wherein the center of pressure on a wing quickly reverses itself at low angles of attack. This could cause the pilot to lose control as the glider suddenly pitches downward. (Picture is of Spratt at Kitty Hawk)

The Wrights did experience problems with control and had to reduce the camber of the wings of their glider in order to minimize the phenomenon. The Wrights give credit to both men for pointing this problem out to them.

The Wrights returned home disappointed with their glider’s performance. They began to suspect that there were errors in the lift and drag data in the Lilienthal tables they were using to design their gliders. They decided to develop their own data.

During the lull in the activities at Kitty Hawk, Spratt shared with the Wrights some of his ideas about measuring lift and drift (drag is the modern term). Determining the value for drag was the most difficult to do. He suggested measuring drag as a ratio of “drift to lift” rather than trying to measure it directly.

Subsequently the Wrights designed two different clever mechanical balances for use in their wind tunnel they built. One balance was designed to measure lift and the other to measure drag. They were unlike anything that Spratt had suggested.

Calculation of Lift: Their lift balance measured the angle of deflection resulting from passing air over a sample airfoil and a reference flat surface. An indicator on the bottom of the device registered the angle of displacement in degrees caused by the amount of imbalance produced by the wind over the airfoil.

A mathematical calculation was made to find the value of a lift coefficient from the indicated angle (the sine of the indicated angle). Knowing the lift coefficient, the value of lift could be calculated from a lift equation.

Calculation of Drag: The Wrights built a second balance that directly measured the ratio of drag-to-lift as suggested by Spratt. Knowing the lift coefficient from the first balance and the drag-to-lift value from the second balance the coefficient of drag could be calculated.

The calculations were a time consuming job. Chanute spent some of his time helping them. The experiments consumed three weeks of effort. The development of the data was a remarkable achievement.

In 1902 Spratt again joined the Wrights at Kitty Hawk for glider trials. Wilbur told Spratt that the 1902 machine was “an immense improvement over last year’s machine.”

The Wrights continued to enjoy Spratt’s company and their debates on the finer points of aeronautical theory.

After Spratt returned home, he sent $10 to the Wrights to cover some of his expenses for his three-week stay in camp.

Wilbur wrote him back, “Moreover we feel that your help was worth more than your board, so you owe us nothing anyhow. — “We owe you, not you us.”

In truth Spratt had contributed little other than the pleasure of his company and the concept on which the drift balance had been based. The latter was the year before.

The Wrights continued their lively discussion through the mail.

Spratt was working on his own theories but he became discouraged as he viewed that his own progress was not proceeding as well as the Wrights. He also was having trouble coping with the rough and tumble of the Wrights debating style and the realization that he was losing most of the arguments.

Wilbur wrote, “I see that you are back at your old trick of giving up before you are half beaten in an argument.”

In another letter Wilbur chided him, “I felt pretty certain of my own ground but was anticipating the pleasure of a good scrap before the matter was settled. Discussion brings out new ways of looking at things and helps round off the corners.”

Spratt in turn complained that their method of rounding off the corners by switching sides in the middle of an argument struck him as dishonest.

Spratt was invited back again to Kitty Hawk in 1903 to witness the attempt for the first manned-flight of the Flyer. Spratt, a good worker, helped construct the sixty-foot monorail to be used for launching the Flyer.

On November 5, the Wrights started the engine on the Flyer for the first time. The engine ran, but the vibration from several missed explosions caused one of the propeller shafts to twist. The shaft would need repair and both of the shafts strengthened. That would require sending them back to Dayton for repair as soon as possible.

Spratt decided to leave camp for home. He was upset and convinced that the Wrights were heading for disaster. He volunteered to take the shafts with him and arrange to have them shipped back to Dayton from the mainland.

The Wrights didn’t see Spratt again until 1906 although they kept up their correspondence during the interval. In one letter Orville described his joy at their accomplishments by writing, “Isn’t it astonishing that all of these secrets have been preserved for so many years so that we could discover them!”

In another letter Wilbur tried to get Spratt out of one of his periodic bouts of the blues: “I am sorry to find you back at your old habit of introspection, leading to a fit of the blues. Quit it! It does you no good and it does do harm.”

The Wrights were on a business trip in 1906 and stopped by Spratt’s farm in Coatesville for a side visit on their way from New York to Philadelphia. Spratt spoke of an airplane he was designing that didn’t need warping of wings, use of ailerons or a moveable tail to exercise control. He called it the “Equilibrium Machine.”

Spratt believed that the design of the Wrights’ system of control was unsafe. He believed that a way should be found to design a machine that was automatically stable. Spratt later complained that Orville and Wilbur didn’t show any interest in his idea.

By now Spratt was increasingly obsessed with the idea that he hadn’t received credit for being the one that told the Wrights about the measurement of the lift/drag ratio.

In 1908 he sent a harsh letter to the Wrights accusing them of depriving him of the credit for the design of the lift balance used in their wind tunnel experiments in 1901.

Wilbur answered, “We have not wished to deprive you of the credit for the idea, and when we give the world that part of our work, we shall certainly give you further credit.” “— But while we considered the idea good, I must confess that I am surprised and a trifle hurt when you say that the advice and suggestions we gave you in return cannot be considered in any degree a fair compensation.” “— But aside from the ideas and suggestions you received from us, we also furnished you copies of our tables, not only those made on the machine ( drag balance) of which your idea formed a part, but also on the pressure testing machine (lift balance).” — “I can cannot help feel that in so doing we returned the loan with interest, and that the interest many times outweighed in value the loan itself.”

In 1922, Orville was compiling a history of the development of the first airplane and wrote Spratt asking for copies of letters that Wilbur and he had written to him about their wind tunnel and propeller experiments.

Spratt responded by repeating his grievance and refused to send the documents. The friendship soured. Orville never wrote to him again.

One month before Spratt died in November 1934, he flew an airplane that he built. Spratt claimed that the machine incorporated all of his theories about airplane stability that he had devoted most of his life discovering.

It was a bizarre airplane. In an old film clip, Spratt is shown suspended like the weight on a pendulum several feet below the wings of the frail biplane.

Sprat claimed that the machine incorporated all of his theories about airplane stability that he had devoted most of his life discovering.

It is a sad commentary on Spratt’s life that a man who had been a confident of the Wrights and an eye witness to the events at Kitty Hawk, was featured with his airplane in a humorous newsreel clip called Aeronautical Oddities.

References: The Bishops Boys by Tom Crouch; Wilbur and Orville by Fred Howard; “The Forgotten Third Wright Brother” by Joe D’Angelo, Coatesville Ledger.

Edward Huffaker was another of the young men that Chanute sponsored. He was building a glider for Chanute and Chanute prevailed on the Wrights to allow Huffaker to test the glider at Kitty Hawk while the Wrights were camping there during their own 1901 glider experiments.

It wasn’t long after Huffaker’s arrival that the Wrights found he was a disagreeable presence, unlike the friendly feeling for George Spratt, another protégé of Chanute who joined them.

On June 26 and 27, 1901, Chanute visited the Wrights on the way to Chuckey, Tennessee where Huffaker was building a glider designed by Chanute. Two days after visiting Huffaker, Chanute wrote Wilbur asking for his permission for Huffaker to bring the glider to their camp and attend the Wrights’ test flights at Kitty Hawk. Huffaker could test Chanute’s glider and be of help to the Wrights. Chanute assured Wilbur that he was reliable.

Wilbur agreed to his attendance as a favor to Chanute.

On paper Huffaker appeared to be a valuable person to have around. He had attended college at Emory and Henry where he graduated in 1876, and completed a master’s degree in physics from the University of Virginia in 1883.

He was interested in aeronautics and began making small glider models in 1892. From 1895 to mid 1896 he worked for Samuel Langley at the Smithsonian Institution, designing wings for Langley’s Aerodromes, and now he was working for Chanute.

When Wilbur wrote the Smithsonian in 1899 asking for information on aeronautics, one of the papers he received was “Soaring Flight” by Huffaker.

Langley praised, “Soaring Flight.” In the introduction to the paper Langley wrote, “I put trust in the good faith with which he reports his observations and in the conscientious care with which he has made them.”

Langley, who was fastidious, didn’t approve of Huffaker’s habits. He read documents with his feet on the table and he chewed tobacco and would squirt a stream of tobacco juice into a spittoon on the other side of the room.

The Wrights arrived at Kitty Hawk on May 10th and established their camp four miles south at Kill Devil Hills where they were soon plagued by mosquitoes. When Huffaker arrived one week later, Orville wrote to Katharine, “He can’t decide which is worse, the mosquitoes or Huffaker.”

Orville and Wilbur found it difficult not to laugh when they first saw the glider Huffaker brought with him.

The wing struts for the 5-wing glider were made of cardboard tubing instead of wood. The wings were designed to fold for easy storage and the fabric was attached to the wings so as to automatically vary their curvature with changes in the wind.

The design was in keeping with Chanute’s idea that a glider could be made that would provide automatic control in flight.

When Chanute saw that Huffaker had substituted cardboard for wood in the struts, he was not happy. He decided to go ahead with test flights at Kitty Hawk anyway.

At Kitty Hawk, the glider was found to be too frail to fly and failed to survive a heavy rain. Huffaker quickly gave up any attempt to fly before Chanute even arrived in camp.

Wilbur took a picture of the rain-soaked remains of the glider and later sent a picture of it to Spratt with the advisory, “If you feel the you have not got much to show for your work and money expended, get out this picture and you will feel encouraged.”

During the remainder of Huffaker’s stay in camp he helped launch the Wright’s glider and took notes. He and Spratt also provided some technical help when they advised the Wrights that the pitching problem Wilbur was experiencing during flight might be caused by the sudden reversal of the center of pressure on the wings.

Overall Huffaker was amazed at what the Wrights were achieving with their glider. The Wrights didn’t share his enthusiasm. They knew that there were serious theoretical problems with lift and control yet to be solved. Wilbur was so depressed on the trip home that he said man might never fly in his lifetime.

Chanute had instructed Huffaker to keep a daily record of the gliding experiments until his arrival. When the Wrights examined the notes after they returned home, they found them to be “inaccurate, as the man was shiftless.”

What really infuriated Wilbur was that Huffaker would lay the stopwatches and anemometers in the sand and use Wilbur’s camera box as a stool.

Also, the Wrights, sons of a Bishop, weren’t appreciative of Huffaker’s habit of delivering lectures on character building.

Wilbur thought he was “priggish and lazy.”

Wilbur thought he looked a bit sheepish when he finally left camp on August 8 with Wilbur’s blanket. He had the habit of borrowing tools and personal items without permission and not taking care of them.

He was still wearing the shirt he had put on soon after his arrival. On top of other everything else, Huffaker’s personal hygiene was poor.

The Wrights arrived home on Thursday, August 22. Katharine wrote her father, “They can only talk how disagreeable Mr. Huffaker was.”

A year later the Wrights were still upset. Chanute had written them about sending another protégé to their camp. Wilbur wrote back, “It was our experience last year that my brother and myself, while alone, or nearly so, could do more work in one week, than in two weeks after his (Huffaker’s) arrival.”

1905 Plane Parts

by Dr. Richard Stimson

in The Kitty Hawk Years

Margaret Hollowell sent to Orville Wright in 1928 a number of items she had collected from Kitty Hawk and asked him to identify them. He laid the request aside and forgot about it until nine years later.

He had his secretary Mabel Beck sent a letter to Hollowell to find out if she still lived at the same address. She did, so he wrote the following letter to her on December 27, 1937.

Miss Margaret Hollowell

Bay Side,

Elizabeth City, North Carolina

Dear Miss Hollowell

I am reporting under separate cover all of the material sent to me in 1928 for identification, excepting two small wooden wheels. I am not returning the letter because they were never used on any of our gliders or flying machines and have no value.

The two pieces of cloth were from the covering of the wings of the 1905 motored plane. The unvarnished ash pieces are ribs of the 1902 glider.

The signature to the letter of August 17, 1908 to you was written by my brother, Lorin.

The paper targets were made in May 1908. The initials W, C and O indicate Wilbur, Charles Furnas, and myself.

Comment: He is referring to gun targets. The Wrights would set them at 50 yards and compete for who could get the best score. The initials were written next to the bullet holes. Charles Furnas was a Dayton mechanic who joined the Wrights at Kitty Hawk in 1908. He became the first airplane passenger while he was there.

The motored plane, of which you have the parts, was flown at Dayton in 1905. In 1908 it was taken to Kitty Hawk so we could get practice before attempting to carry out contracts which we had engaged to fulfill that year.

The wings of the 1905 machine and most of the wooden parts we left in one of the buildings at Kitty Hawk.

One of the coast guards at the Life Saving Station needing lumber, stripped the siding off the buildings and left the 1905 plane and our 1902 glider exposed to the elements.

Sincerely yours,

Orville Wright

Comment: The 1902 glider was left behind after the first flight in 1903. When the Wrights returned to Kitty Hawk in 1908, they found the skeleton of its wing sticking out of the sand outside the original hanger. The roof of the hanger had collapsed spilling the 1902 glider on the ground.

The 1905 Flyer was left to rot in the sand at Kitty Hawk after its last flight in 1908. It was later salvaged by others and restored under Orville’s guidance. It now resides in splendor at Carillon Park in Dayton.

Home for Christmas

by Dr. Richard Stimson

in The Kitty Hawk Years

When the Wright brothers left Dayton for Kitty Hawk on September 23, 1903, they never thought that they would have trouble making it back to Dayton in time for Christmas. Christmas was a traditional family celebration that they didn’t want to miss and they had promised the family they would be back in Dayton for Christmas.

To make it back on time, they took uncharacteristic risks in dangerous weather conditions. Bad weather and mechanical failure had conspired to delay their progress.

The brothers arrived at Kitty Hawk on Sept. 25. They planned to build a new larger hanger in which to assemble and test their new Flyer. The Flyer was never assembled in Dayton.

They were pleased to find that their tools, provisions and lumber for the new building had arrived. The parts for the Flyer would arrive later.

They found that the existing building that served as their living quarters the previous year was wrecked by the winter’s storms. Fortunately, the 1902 glider they had left in the building was undamaged. That was important because they planned to fly the glider to sharpen their piloting skills.

They hired Dan Tate to help them rebuild the old building into a real home away from home and build the new hanger. Tate would also help in launching the glider. They wanted to maximize the amount of practice time in the air before trying out their Flyer so they worked on the new building on rainy and calm days and practiced gliding on days when the wind and weather permitted.

They first flew their glider on Monday September 28. They flew some 75 times off Big Kill Devil Hill that day. The wind was blowing 31 mph at times. The buffeting gave them good practice in controlling the craft.

In total they made some 300 glider flights. Their best flight lasted over 30 seconds and broke all of their old records. It was fun and they were improving their piloting skills with each flight. It was a good beginning.

On October 8 the new hanger was completed just in time to receive the last shipment of parts for the Flyer. Unfortunately, bad weather also arrived. The driving wind and rain almost blew the roof off of their living quarters. The storm lasted for four days and then turned cold. Many days were too cold to work. Their wood-burning stove made things uncomfortable inside, spouting smoke filled soot. They eventually were able to acquire a stovepipe and vent the smoke through the roof.

Orville and Wilbur were worried about other things besides the weather. They knew that Samuel Pierpont Langley was intending to fly his machine in early October. If successful he would win the race to be the first to achieve manned, heavier-than-air, powered flight.

They needn’t have worried. Langley’s machine, with Charles Manly at the controls, crashed into the Potomac River upon takeoff using a catapult system mounted on a houseboat.

Orville and Wilbur were still concerned about Langley’s effort, so they planned to launch their new Flyer by Nov. 1 as soon as it was ready instead of taking the more cautious approach of first flying it as a kite and then as a glider as they had originally intended.

By mid October the upper wing of the Flyer had been assembled and covered. On Nov. 5, the machine was nearly completed and ready for the first power plant test. They needed to confirm the accuracy of their theoretical propulsion calculations, which couldn’t be confirmed in Dayton. It was doubly important because they now found that the Flyer weighed 75 more pounds after assembly than they had originally calculated.

From the beginning, they experienced problems with the engine. It misfired which caused the propellers to vibrate so severely that the propeller hubs broke loose from where they were welded to the propeller shafts.

This caused a considerable delay in their plans, because there were no machine shops at Kitty Hawk, forcing the Wrights to return the shafts to Charlie Taylor for repair in Dayton. To add to their concern, Octave Chanute arrived in camp with news that Langley intended to try again to fly in early December.

The delay caused by repairing the propellers would be 15 days. Chanute added more cause for concern.

Chanute, with half a century of engineering experience behind him, told the brothers that no one had designed a flying machine with such small margins of safety as theirs. He disagreed with their calculations that their chain drive system would experience only a 5% power loss due to friction. Chanute said that the loss would be at least 25-30%. He didn’t think the propellers would receive enough power to achieve flight.

After 6 days Chanute departed camp leaving the brothers doubting themselves.

As was their routine when faced with problems they went to work conducting tests, going over their calculations and making adjustments.

They tested their launching procedures by laying a 60-foot launching rail on the side of Big Kill Devil Hill and launching the 1902 glider using the front elevator control. The glider successfully lifted off the ground 5 out of 6 times.

That was the end of using the aging glider, however. It was beginning to deteriorate and the wood and the cloth were showing the effects of the heat in the hanger. It was no longer safe to fly.

They next tested the strength of the front elevator of the Flyer to withstand strong wind loads. Their test method was to suspend the Flyer by the wing tips from the rafters of the hanger and add 450 pounds of weight.

The wings passed the weight test but the “Pride of West” fabric on the wing tips badly wrinkled. The fix was to rearrange the control wires to maintain aerodynamic efficiency.

The next test was a power transmission test to check out Chaunut’s claim that the Flyer could not develop sufficient power to get off the ground because of transmission loss.

Their test method was simple but effective. They hung a weight equivalent to what the engine would exert on the chains on a chain threaded over one of the sprockets. They were relieved to find that the force required to raise the weight indicated the power loss was just about equal to their original estimate of 5%.

They now needed to test the entire propulsion system in operation. The repaired propeller shafts arrived about noon on Nov. 20. They installed them and were ready to begin the test that evening.

Then they ran into another problem. The vibration from the engine was so severe that both sprocket wheels came loose within seconds. Nothing they did to tighten the nuts that locked the sprocket wheels to the propeller shafts did any good. Then they turned to a method they had used on bicycles. Glue them. They had brought Arnstein’s Hard Cement with them. They used it in Dayton to glue tires to wheels. They were using it at Kitty Hawk to seal letters. They spread it on the threads of the sprocket and heated the assembly. It worked.

They also found the source of the problem causing the vibration. The vibration had caused the fuel valve to slip resulting in an uneven flow of fuel.

At last they were ready to test the entire propulsion system.

First they checked propeller speed. The results exceeded expectations. They hoped for 305 rpm and got 350 rpm during a one-minute test.

Then they conducted a propeller thrust test. The test method was to set the Flyer on rollers. A rope was tied to the machine, strung over a pulley and tied to a 50-pound box of sand.

The engine was started and the propeller pushed the machine forward. The thrust force was measured by the weight lifted. The brothers found that their propellers were generating 132 pounds of thrust at a propeller speed of 350 rpm.

Their theoretical calculations predicted a thrust of only 90 pounds. That was great news. The extra thrust would handle the extra weight of their machine. Chanute was wrong; the machine would fly.

They performed one more test with the engine running. They again suspended the Flyer by the wing tips inside the hanger. This time a pilot was aboard while the engine was running. There were no problems, proving that the in-flight strength was satisfactory.

They were about ready to fly. Than disaster struck. They found hairline cracks in one of the propellers.

Orville went back to Dayton on Nov. 30 to make new propeller shafts from spring steel instead of the hollow steel tubing they had used.

Time was of the essence because they heard that Langley was about to make another attempt to fly and Christmas was only a month away.

Orville returned to Kitty Hawk on Dec. 12 with the new propellers. He had good news. On the return train trip he read in a newspaper that on Dec. 7, Langley had failed again, and for last time, because he had run out of funds.

The evening of Orville’s return they installed the propellers and were ready for a test flight that evening. They were disappointed; there was insufficient wind.

Instead, they tested the launching system by running the machine along the launching rail under its own power. On one of the runs the tailframe snagged the rail and broke. It was a minor repair and was quickly fixed.

Orville and Wilbur were now anxious to conduct a full flight test. December 13 was a perfect day to fly – warm weather and 18 mph wind. But it was a Sunday and they didn’t work on the machine or fly on Sundays because of their religious beliefs.

Dec. 14 was another beautiful day but the wind was only around 5 mph. They decided to give it a try with the launching rail on a slope of 9-degrees on Big Hill to provide a downhill start. Gravity would compensate for the light wind.

Five men from the local lifesaving station a quarter of a mile away with two boys and a dog answered the call to help drag the Flyer to Big Kill Devil Hill.

The engine was started and the 2 boys, startled by the noise, ran off.

A coin was tossed and Wilbur won the first chance to fly a powered flying machine. The machine, under power, moved down the rail with Orville running alongside steadying it at the right wing. About 40-feet down the rail the machine was moving too fast for Orville to keep up and Wilbur turned the front elevator up sharply, not realizing how sensitive it would be.

The Flyer surged in a steep trajectory upward to about 15 feet where it stalled and slowly lost altitude, hitting the ground with the left wing tip. The impact broke a skid and damaged the front elevator. Wilbur attributed the accident to his inexperience.

They were ecstatic despite the rough flight because they knew the machine was capable of flight. They just had to learn to fly the machine. Wilbur wrote his father, “Success assured keep quiet.”

The next two days they made repairs to the machine while watching two beautiful days pass by. On Dec. 16 they were ready to try again, but the weather wasn’t – there was no wind.

The next day, Dec 17, they got the wind and then some. Puddles from the rain that fell during the night had frozen and they measured the wind to be blowing 24-27 mph. Even the birds weren’t flying. That should have been an omen.

They did wait until 10 o’clock, but became impatient and with their mind set on being home by Christmas, decided to give it a try. They hug out the signal flag to notify the men at the lifesaving station they were going to make the attempt.

The rest is history. They made four successful flights on the 17th and became the first to make manned, heavier than air, powered, controlled, sustained flights. The last flight went 852 feet in 59 seconds.

They sent a telegram home with the exciting news of their success. According to their niece, Ivonette Miller, who was 7 in 1903, the children were more excited that Wilbur and Orville would be home for Christmas. She recalled that they said something like:

“Oh, goody, Uncle Will will be home in time to carve the Christmas turkey!”

Amanda Wright Lane, the great-grand niece of Wilbur and Orville, speaking at the Wright Memorial in Dayton on the occasion of the annual Wreath-laying ceremony commemorating the 102nd anniversary of the first flight said:

“The Wright family was thrilled to learn about that first flight, but they were happier yet to know that meant the boys, great cooks, would be home in time for Wilbur to stuff the Christmas turkey and for Orville to make his cranberry bunny, served at holiday meals.”

They arrived home the evening of Dec. 23 in time for a merry family Christmas.