Those Wright Brothers are at it Again

The original homebuilt.

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We have become used to hearing rumors about those bicycle shop boys from Hawthorn Street in Dayton; they went from flying kites on strings to riding those kites themselves. But the latest design to come out of their small shop has everyone spinning—and we predict that kits will soon be “flying” out the door for their latest creation—a kite with a motor that can actually lift itself and its occupant off the ground and fly through the air under control!

This is not the preposterous claim of a quack or charlatan who professes to have mastered the emerging science of aeronautics. To the contrary, the Wright brothers have provided photographic evidence that they have successfully flown a manned, powered, heavier-than-air craft that is truly capable of controlled, sustained flight.

This photograph clearly shows the anhedral (droop) of the wings, as well as the long twin hand-carved propellers.

A visit to the Wrights’ shops and flying field has firmly convinced us that this is the real deal. We even had a chance to fly the training device for this new type of machine and feel it is time to share this story with the world.

As any of our loyal readers know, it is our policy not to review new kits or plans until we are certain that production is underway. But in the case of the Wright Flyer, as this new machine is called, we are making an exception—it is simply too exciting to go unnoticed.

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KITPLANES® has always covered the gamut of homebuilding. From steam engines to rubber power, from air machines constructed of wood to those using actual feathers and glue—we don’t discriminate. The Wrights, Orville and Wilbur, as they are becoming known, have been using wood and muslin cloth for their kites now for several years, and their results seem to prove the value of this construction method.

The front rudders (now beginning to be called “elevators”) are used to control the pitching of the machine. The wing is seen to be warped—the Wrights’ unique method of controlling lateral balance.

Beginning at the turn of the century, they have flown successively larger kites at their winter flying grounds on the outer banks of North Carolina. The winds of the Atlantic Ocean beaches, and the large sand dunes at their location of choice, have provided a good proving ground for their experiments. Although they studied the works of Lilienthal and Chanute using mono-wing designs, they early on settled for a bi-wing contraption because of the inherent stiffness afforded by what many call a “box kite.” Using the upper and lower wing design doubles the amount of lift, and with appropriate diagonal bracing wires, the structure forms a truss with exceptional strength for its weight.

Materials and Construction

While many flying experimenters have tried exotic materials, including one who chose to emulate the birds by using natural feathers, the Wrights have stuck with easily obtainable wood, fabric, and steel fittings that can be found in most American towns and farms across the country. The broad wings and box-like construction is primarily wood—the straight sections being made from spruce and the curved members constructed of ash, both perfectly suited for their design applications. These woods can be obtained from reasonably priced suppliers in most areas. Straight and clear grains are important however, so builders are advised to carefully choose the materials for any craft that they build.

Like most new aircraft, the plans are somewhat primitive and require the builder to use his imagination when it comes to details. Potential builders should find, however, that the construction methods and materials should be familiar to anyone growing up in America with an inventive nature. The Wrights caution that some measurements are approximate.

The wings are covered with a fine, tightly woven cotton cloth to prevent air from leaking through. The fabric is stitched and glued in place, then sealed with a paint that is made from paraffin dissolved in kerosene. The Wrights might have learned this from previous aviators or from the sailors around their Kitty Hawk flying grounds who use the mixture on their sails.

All of the metal fittings on the machine were made from mild steel, and the rigging was done with 15-gauge bicycle spoke wire, a material with which the Wrights are extremely familiar. As with many modern American machine designs, some parts that were purchased by the Wrights were originally used for another purpose. These parts can be sourced from the same suppliers the Wrights used. For instance, the wingtip bows were made from bows originally designed for a folding carriage and were sourced from S.N. Brown Co., a maker of carriages in the brothers’ hometown of Dayton.

The Wrights have developed many specialized and ingenious construction techniques for making their machine extremely light, while strong enough for flight. The ends of struts are wrapped in wire where brackets are attached, and ribs are glued and lightly nailed to spars. Builders will want to carefully examine plans, drawings, and the limited available photographs to ensure that they learn the proper techniques for this light construction, lest they end up with a machine that looks like the Wright Flyer, but weighs as much as a carriage—in which case, it will never get off the ground.

When going through the plans, builders should be aware that some things might not be intuitively correct. For instance, the Flyer is not symmetrically designed. The engine outweighs the brothers by 35 pounds. The brothers both weigh between 140 and 145 pounds, so the right wing on the engine side is four inches longer than the left wing. That is the left wing is 20 feet even and the right wing is 20 feet, 4 inches long. So, if you weigh more or less than the targeted weight, you may have problems flying the machine.

As with any prototype aero machine, some changes have been made that are not reflected in the plans, so it is important for the builder to evaluate their own understanding of the plans, and if confused, check with the factory.

This rear view of the installed powerplant shows the flywheel and the bicycle chains used to drive the twin propellers, as well as the ignition magneto. The exhaust valves are clearly visible right next to the operator’s right side.

Modern Propulsion

The thing that sets the brothers’ machine apart from everything else that has been tried to carry men aloft is the 12-horsepower motor, which was built to their specifications by bicycle shop mechanic and co-inventor, Charles Taylor. While earlier attempts at heavier-than-air flight have centered on using the old standby, the steam engine, and at least one experimenter tried compressed air, these have proven to be too heavy and/or cumbersome, compared to the latest in gasoline-fired internal combustion. The Wrights were looking for an engine that could produce between eight and 10 horsepower and weigh less than 200 pounds. While it might have been possible for the automotive industry to supply such a motor, their need for a single example would have made such a custom machine, made by a large firm, untouchable to their modest means. Therefore, they collaborated with their hired bicycle mechanic to produce the necessary parts to assemble their engine.

Engine bottom view—note the oil collector tube under the bottom of the crankcase, as well as the four mounting legs which must find firm bolting locations on the machine’s frame.

The engine that resulted is water-cooled, with a radiator mounted to one of the forward struts of the flying machine. The large flywheel is designed to damp out vibrations from the four firing cylinders. A magneto mounted near the flywheel provides energy for the spark ignition. Externally-mounted springs for each intake and exhaust valve run very hot, with the suction-activated intake valves on the top of the flat, inline four and the exhaust valves (driven by the camshaft) on the bottom. The air intake and carburetor (a simple affair consisting of a valve which drips fuel into a tin can, then on to the hot water jacket to vaporize it) are on the top of the motor, while the timing chain and gear are on the front. An oil pump for lubrication is located on the bottom of the engine, driven by a worm gear off of the valve train camshaft. The pump collects oil that drains from the crankcase and routes it through a feed line which drips the oil onto the surface of the pistons. The oil then drains down into the crankcase to lubricate the main bearings before collecting in the bottom of the crankcase, where it splashes to help lubricate the rest of the crankshaft before draining back into the collection system for the oil pump.

The Wright’s engine is the first successful purpose-built motor to power a flying machine. Details of the technology can be seen in this cutaway view.

The engine block is cast from an alloy of 92% aluminum and 8% copper to achieve both strength and light weight. The cylinders are steel, and some other parts of the engine are built from cast iron. Almost all of the parts have been custom made by the Wrights or Taylor, and we suspect that most who choose to build their own Flyer will decide to source engine parts from the Wrights themselves. While it is not extremely difficult to manufacture such parts, getting the dimensions and materials correct can take some trial and error, and many builders will choose to take this shortcut to getting in the air.

This photograph clearly shows the engine mount legs as they attached to the wing. Also of note is the timing chain, which drives the camshaft and operates the valves.

Of course, the engine is of no use unless the energy obtained from the machine is transmitted to the air to provide forward thrust. The Wrights achieve this through the use of two very thin propellers, a breakthrough in propulsion efficiency based on their own experiments with airfoil sections. The two propellers are driven at speeds of 350 revolutions per minute via bicycle chains (a mechanism with which the brothers are well acquainted). Most flight enthusiasts have, to this point, tried propellers with broad blades, turned slowly like a windmill. The brothers, through experimentation, determined that long thin blades turning quickly provide much better propulsion. One secret of the Wrights’ design is the twist in each blade. Because the airflow at the root is much slower than at the tip, the optimum angle of the airfoil has to change for maximum efficiency. Carving the blades takes time, and carefully laminated spruce wood is required for maximum strength. It has yet to be determined if the Wrights will produce propellers for their plans or kit customers, or if builders will be left on their own to follow the drawings.

As can be seen in this drawing, the cylinders are four inches in diameter with a four-inch stroke. The four-cylinder configuration lowers the vibrations inherent in a gas-explosion engine.

Let’s Fly!

What sets the Flyer apart from all previous machines is its ability to launch from level ground, so that is the best place for us to start. While most of the gliders we have seen require a tall hill and a stiff wind (as did the Wrights’ earlier contraptions), we were able to do our demo flights from the same location as the brothers—a level spot below the tall Kill Devil Hill near Kitty Hawk, North Carolina. Because the sand was soft, and not conducive to a low friction coefficient for the skid landing gear, a track (consisting of a string of long straight lumber with cross-pieces to support it in the sand) has been prepared that matches up with small wheels on a cradle that supports the Flyer. While this arrangement doesn’t allow the operator to launch his craft from any random point, neither does the need for a large hill, so we don’t see this as a problem.

In keeping with sound safety practices, the Wrights had only a few necessary helpers to move the machine around for their first flight. Limiting the attendance removed the pressure to fly that might have come from a large crowd looking for a spectacle.

Climbing into the machine requires a bit of dexterity and care. The surfaces are fragile because of their light weight (necessary for flight), and the maze of tensioning wires needs to be navigated in order to secure oneself in the operator’s cradle. Once lying face down, the operator needs to crane their neck back to see forward. The hips should fit snuggly in the wing-warping cradle, while the right hand is used on the controls for the front elevator. There is a brace for the feet in order to help steady the body when throwing the hips back and forth for controlling the roll of the craft.

Anyone who chooses to build a copy of the machine is advised to study the construction details carefully. Here can be seen the wire reinforcement for the ends of the struts, as well as the short lengths of chain and a sprocket used in the wing-warping system.

The 12-hp gasoline engine is situated on the wing to the operator’s right, and the bicycle chains feeding power to the two pushing propellers are in the rear, so it is best to keep one’s feet down. Starting the engine is accomplished with a helper throwing the props to turn the chains—and hence the motor. There is no doubt when the engine has started, as the noise of the unmuffled motor and the running chains is quite intense. Instrumentation is strapped to the strut to the front and to the right of the operator and includes a rev counter and stopwatch.

This view shows how the fabric is stitched and tacked to the wooden wingtip bow. It is made impervious to air passage using a concoction of kerosene and paraffin.

With the engine running, all that is left is to release the catch holding the craft back, and it slowly starts its way down the track, accelerating as it goes. With the track oriented into the prevailing wind, the speed of the air over the wings will reach that required to provide lift fairly quickly, and in this author’s experience, that always happened before the end of the track was reached. The front elevator control is fairly sensitive once flying speed has been reached, and the new operator is urged to be careful not to overcontrol, once the surface become effective. Too much elevator will raise the nose abruptly and with too much angle to the relative wind, the wings will actually lose lift and slow down.

The right amount of control will be learned by those adept at maneuvering in flight, however, and the feeling of lifting off of the earth is both exciting and terrifying at the same time. The wing-warping controls, activated by throwing the hips back and forth, are slow to respond, so the operator needs to anticipate the need for correction should a wing begin to drop. Any turbulence of the air makes this extremely difficult, so flight in calm air is most desirable. If the operator should feel a wing beginning to drop, prompt action with the hips needs to be made. It is easy to throw the hips too far, as initially, there is little response to the action—but eventually the warping effect will catch up to control input, and more roll than desired is the result.

Some operators have come up with a technique to initially throw in more control than is going to be needed to achieve the bank rate they desire, then as soon as they feel the aircraft respond, they take out much of the input. This gets the craft responding more quickly, but the operator needs to be quick not to keep the excessive bank command into the cradle, and take the excess out immediately. All the while that the operator is managing bank, he needs to be watching the elevator very carefully. It pays to memorize the elevator’s position relative to the horizon in level flight (once this has been attained), and not allow it to vary even the slightest amount. Too high and the wing will cease lifting. Too low and a dive into the ground will result.

Another trick to flying the new craft is to not try and fly very high. A little time on the beach before the first flight attempt convinced this operator that the local pelican birds have things figured out—they skim the waves less than a wing height above the water. It appears that this gives them a cushion of air between their wing and the water, making flight easier. If they rise above this height, they have to flap their wings, adding energy to stay aloft. Taking this lesson from our feathered friends to heart, it appears that if the Wrights’ craft rises more than a short distance above the ground, the cushion of air dissipates and the small motor does not have enough power to keep it flying. At this point, the operator is in a precarious position, for the descent is inevitable, and there is very little time to lower the nose to gain more airspeed before impacting the ground.

The wings, being rather long, are a limiting factor in being able to bank the craft because of this low flying height. Dipping a wing a small amount is the way to initiate a turn, but if it is dipped more than a few degrees at low height, the tip will drag, bringing the flight to an abrupt end—usually with a splintered wing. Very gentle turns are advised, and in fact, the brothers have endeavored mainly to keep the craft moving in a straight line up to this point in time. The hope is that future aircraft will be able to make complete circles, but the Wrights admit that they will need a more powerful engine to achieve more speed, greater lift, and therefore greater height before this dream will be realized.

The operator that manages to lift off, keep an adequate pitch attitude to maintain altitude, and conquers the needed timing to keep the wings level can expect to continue in a straight line, aloft and free from the earth, for as long as they can keep their level of concentration up to the task. It is best to keep the eyes forward and look for obstacles, and if one presents itself, the prudent course of action is to land, rather than to attempt a maneuver around it. While the Wrights would like us all to assume that the craft can be maneuvered, the reality is that as soon as a wing dips more than a few degrees, it is very difficult to bring it back up before the craft begins to cartwheel.

Landing the craft is theoretically a matter of cutting the power and allowing the machine to settle to the ground as it decelerates, with a small amount of back stick to keep the nose up at the last moment. Here again, we have learned by watching the birds as they decelerate and bring their heads up, presenting their wings to the relative wind to slow to a stop. While the Flyer cannot achieve this extreme level of pitch, the idea of keeping the nose from digging in is a good one. Such landing technique is still theoretical, as no one has yet ended a flight of their own volition, without the interference of the ground or other objects—but everyone who has attempted flight has this image of a landing in mind when they start.

We anticipate that when future operators look back at the Flyer, they will not think kindly of its unique handling qualities or performance. Its speed range is probably only a few mph from not being able to produce lift at top speed. It is very difficult to handle, and in fact, future operators might unkindly say that it is unflyable—and they might be correct. However, as a first effort, going where no one has gone before, the Wrights have achieved where others have failed. They might ask critics to show them their own flying machines in challenge—and the critics will be forced to retreat in shame.

Overall, we found the sensation of flight to be exhilarating and novel, for few human beings have ever achieved such a state. The machine itself is, we are afraid to say, extremely hard to control for the novice. Time spent on the gliders on the hill can train a person to a certain level of proficiency and familiarity with the controls, but they still must have a quick mind, keen perception of motion, and intense concentration in order to manage the craft. We expect that with more experience and modifications, the air machine will become a reliable method of leaving the ground. But for now, anyone who chooses to build the kit should plan on buying extra wingribs, struts, and muslin cloth for repairs during the learning phase.

Go Forth and Fly!

We believe that the age of practical flight is, if not here now, soon to be upon us, and that the Wrights’ new craft is probably the best way of getting into this new field. They are anticipating releasing plans and kits in the near future, but their exact timetable is vague. Other groups are said to be experimenting with similar configurations, hoping to achieve the same success as the brothers, but with the lead already attained by the men from Ohio, we expect to see their version of an aeroplane flying out of barns and basements in great numbers in the near future. There are few exotic materials or techniques involved in the building, except for the engine, and it is hoped that some form of engine kit—or complete engines—can be provided by the Wright Company to accompany their plans and airframe materials kits. The handy farm tinkerer might very well be capable of producing their own engine if they have access to the correct materials and tools; but it might take a long time to perfect such a motor.

We do look forward to the day when companies devote themselves to producing air machines in great numbers. But for now, we expect that the vast majority of flying machines will be constructed and flown by backyard and barn experimenters for their own entertainment and education. If the day ever arrives where these machines can carry more than one person aloft, there is a potential for business purposes, but we encourage anyone with the ambition for flight to contact the Wrights and get started now. The lure of flight is both addictive and seductive, and those who have tasted it will never again be satisfied to remain upon the ground.

For more information visit www.nps.gov/wrbr/index.htm, www.nps.gov/daav/index.htm and www.wright-brothers.org.

Photos: Paul Dye, Darrell Collins/National Park Service, NASA, Smithsonian Institution, Wright Brothers Aeroplane Company

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Paul Dye
Paul Dye, KITPLANES® Editor at Large, retired as a Lead Flight Director for NASA’s Human Space Flight program, with 40 years of aerospace experience on everything from Cubs to the Space Shuttle. An avid homebuilder, he began flying and working on airplanes as a teen, and has experience with a wide range of construction techniques and materials. He flies an RV-8 that he built, an RV-3 that he built with his pilot wife, as well as a Dream Tundra they completed. Currently, they are building a Xenos motorglider. A commercially licensed pilot, he has logged over 5000 hours in many different types of aircraft and is an A&P, EAA Tech Counselor and Flight Advisor, as well as a member of the Homebuilder’s Council. He consults and collaborates in aerospace operations and flight-testing projects across the country.

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