First Practical Airplane, Part 1

by Dr. Richard Stimson

in Dayton Celebration Events

Design of Wright Flyers II, III

A momentous event in the history of the airplane occurred 100 years ago on October 5, 1905. It was the first flight of the first practical airplane piloted by Orville Wright over Huffman Prairie, a cow pasture in Dayton, Ohio

On that occasion Wilbur flew thirty circles over the field, landing only when fuel was exhausted. He had flown the 30 circles in more than 39 minutes, exceeding the sum of all 109 flights made in 1903 and 1904. His average speed was 38-mph over the 24 miles he flew. It was the 48th flight and second to last flight of 1905.

He demonstrated that the Flyer was capable of taking off, flying for an extended period of time under the control of the pilot, and landing safely.

It was the culmination of seven years of research, disappointment, brilliant engineering, risk of serious injury, disparagement and ultimate success.

The Wrights first great success was at Kitty Hawk in 1903 with the Flyer I. The craft, however, was not maneuverable or controllable. The following year they began work on a practical airplane at Huffman Prairie, a 100-acre pasture eight miles east of Dayton.

1904 Flyer II

April 15, 1904 the Wrights completed constructing a wooden shed at Huffman Prairie to house their new 1904 Flying machine (Flyer II). They located the building as far away as they could from Simms Station on the traction line from Dayton for their privacy. It was on the south side of the prairie adjacent to Hebble Creek. The creek was named after my great-great Grandfather Henry Hebble who had built a home nearby.

The machine looked very much in appearance like the 1903 Flyer. They reduced the wing camber from 1/20 to 1/25 and substituted white pine for spruce for the wing spars. Both of these changes were reversed back to the original configuration in the 1905 Flyer.

The biggest improvement they made was that they designed a new engine for Flyer II. It had slightly larger pistons and produced about 16-hp. The engine had improved lubrication and a fuel metering system. The same engine was used in the 1905 Flyer and by that time the engine was worn-in and producing 20-hp.

The 1903 propellers were reused initially but were damaged in a crash on August 10th and were replaced with propellers having great blade width.

For the 1904 Flyer as with the 1903 Flyer, the pilot lay in the prone position and the wing warping and rudder controls were interconnected.

Later they added some 70-pounds of iron bars to the forward frame that supports the canard to move the center of gravity (c.g.) forward to improve stability. It helped slow down pitch oscillations and decreased elevator sensitivity. It was still not a complete solution. The gross weight of the craft was 900 lbs.

Their first flight was attempted on May 23rd using a new 100-ft long launching rail. Several flights were attempted but rain and insufficient wind prevented takeoff. Nor was there much success over the next five months. Flying consisted of short hops of 100 to 200 feet ending with crashes and broken parts. Their record fourth flight of 852-ft at Kitty Hawk in 1903 was not exceeded until August 13.

Their next attempt was on May 26. Orville flew about 25-ft.

Their biggest problem was insufficient and unpredictable wind and less dense air at the 815-ft elevation in Dayton as compared to sea level at Kitty Hawk. It was frustrating. They would lay the track in one direction and then the wind would change direction and they would have to relay the track in another direction.

It is estimated that the less dense air caused a 13% reduction in lift. The first 39 flight attempts were made on a launching rail as long as 236-ft. In contrast the rail at Kitty Hawk was 60-ft long.

Wilbur wrote, “We found great difficulty in getting sufficient initial velocity to get real starts. While the new machine lifts at a speed of about 23-mph, it is only after the speed reaches 27 or 28-mph that the resistance falls below the thrust.”

They decided they needed a catapult launch system to consistently get off the ground. It consisted of a 20-ft tower and a weight that when dropped propelled the Flyer. The weight was incrementally increased over time to 1600-lbs. It was placed in operation on September 7. The ability to take-off improved markedly after that. For the first time they could fly the length of the field without difficulty and complete full turns.

On September 20th Wilbur successfully flew the first complete turn. The flight was witnessed by Amos I. Root, who described it in the January 1, 1905 issue of Gleaning in Bee Culture. Root was the editor and publisher of the magazine.

Root offered to give his article to Scientific American. They refused the offer because they didn’t believe his story.

Their last flight in 1904 was on December 9. While they had had some success, they were still frequently flying out of control. They had trouble with pitch stability and their circles were ungainly and awkward. On tight turns the machine had a tendency to keep on turning. They tried moving the c.g. by moving the pilot position, engine, water tank and ballast but they were still looking for a solution as the season ended.

Between May 26 and December 9, 1904 they made 105 flight attempts with an accumulated total flying time of 49 minutes.

1905 Flyer III

The 1905 Flyer was radically different in design than the 1903 machine. Initially the motor, propellers and drive system were reused from the 1904 machine. The engine’s lubrication system and fuel pumps were improved. The horsepower increased to almost twice the engine of the 1903 Flyer.

The camber was reset at 1/20 again. The anhedral (droop) of the wings used in the 1903/1904 Flyers was removed. The overall machine was longer and a little taller.

A pair of semicircular vanes, called blinkers, was placed between the twin elevator surfaces to prevent sideslips. The propellers had tabs, called little jokers, on the trailing edge to halt deformation. The shape was known as the “bent end” propeller.

The canard elevator was moved forward and its surface area nearly doubled. The vertical rudder was moved to the rear and greatly enlarged.

The interconnection between the wing warping and rudder controls used in 1903/1904 Flyers was separated so that the pilot could control them separately.

The first flight of the new machine was made on June 23. They found that they still were having trouble with pitch and circling. Only eight flights were made during the first several weeks. Each ended in an accident and damage.

On July 14, Orville lost control of the Flyer due to extreme pitch undulations and crashed. He was fortunate to escape injury but the machine suffered significant damage. During the rebuilding major design changes were made.

They enlarged the elevator surface area from 52.74 square feet to 83 square feet and moved the elevator from 7.32 to 11.7 ft in front of the leading edge of the wing. The length of the machine ended up 7 feet longer than the 1903 Flyer

After the modification on August 24, they found a significant improvement in the performance of the machine. Now both Orville and Wilbur could get the flying time to learn how to fly their machine.

On flight No. 39 for 1905, Orville brushed a thorny locust tree with a wingtip leaving some thorns in the fabric. The tree was located in the center of the Huffman Prairie. Orville misjudged his distance and the wingtip brushed the upper branches. The hit forced the Flyer into a tight circle. Orville, reacting to the turn, pushed the nose down. To his surprise, the machine reacted by stopping the turns and leveling out.

The Wrights figured out what the problem was with the tight turns. When entering a turn, the lift much be increased to compensate for centrifugal force that adds to the weight carried by the wings. In turning flight the lift instead of increasing, decreases because in turning, the lift on inside wing decreases as it slows down. The effect is that the inside wing can stall and cause the machine to spin into the turn. The solution is to increase speed by placing the Flyer into a shallow dive and therefore prevent the inside wing from stalling.

In order to stay within the confines of the field their flight paths consisted of oval turns. They didn’t want to stray outside the barbwire fence because of the difficulty of dragging the machine back.

The Wrights, by accident, now knew how to solve the tight circle problem they had experienced in 1904. The solution to recover from a tight circle was to put the Flyer into a shallow dive to increase airspeed to prevent the inside wing from stalling.

Two other changes also led to a complete solution. One was the elimination of the anhedral wing, which had been used since 1903. The other was to decouple wing warping from the rudder to allow independent roll and yaw control by the pilot.

After his No. 48 flight on October 5, Wilbur pronounced the Wright Flyer III capable of rising in the air for an extended period under complete control of the operator, and landing safely. It was the world’s first practical airplane.

One more flight was made on October 16. It was the last flight for 1905. One round of the field was made ending with a landing near their hanger.

Wilbur wrote in December 1905, “Our 1905 improvements have given such results as to justify the assertion that flying has been transferred from the realm of scientific problems to that of useful arts.”

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