Overview of Wright Brothers Discoveries
In 2003, the world will celebrate the 100th anniversary of the
first flight of an airplane by
the Wright brothers. While much attention
will be paid to the events of December 17,1903, at Kitty Hawk, North Carolina,
it is important
to note that the four flights of that day were only one small step
in the development of the airplane. On this page, we show scaled
computer drawings of the six aircraft which the brothers designed
and built leading up
to the first practical airplane.
The process which lead to the first successful airplane is the
same process used by engineers today to solve problems. The brothers
from Dayton, Ohio, began with an interest in flying things. Their
father had brought them a flying toy "bat" powered by a rubber
band in the 1870's. As teens in the 1880's, they built and flew kites.
In the 1890's, they read about the hang-gliding
flights of Otto Lilienthal and his death in an air crash. They recognized
that control of a flying aircraft
would be the most crucial and hardest problem to solve. And they
had an idea about how to solve that problem. They first performed
a literature search to find out the state of aeronautical
knowledge at their time by reading about the works of Cayley,
Langley and Lilienthal. They corresponded with Octave Chanute concerning some of
their ideas. From the observation of soaring birds, they believed
that they could obtain roll control
by warping, or changing the shape,
of a portion of the wing. To test their idea, they built a small
kite in 1899 which could be maneuvered by pulling on two control
Between 1900 and 1902 they built a series of large unpowered
aircraft to develop and refine their ideas of flight. These aircraft
were repeatedly flown as piloted gliders
and as unpiloted kites. Each aircraft was
designed and built in Dayton, but they were flown at Kitty Hawk
where higher and more consistent winds were to be found.
The 1900 aircraft was the
first plane flown by the brothers. It demonstrated that roll control
could be provided through wing warping. On this aircraft, pitch
control was provided by an elevator,
called a canard, which
was placed at the front of the aircraft.
The location was probably chosen for safety reasons; to provide some structure
between the pilot and the ground in a crash. There is also a
small aerodynamic lift advantage in placing the elevator at the front
unlike modern airplanes where the elevator is placed at the rear.
Even with the increased the lift, the aircraft did not perform as well
as the brothers predicted using available data.
The 1901 aircraft had the
same basic design as the 1900 aircraft, but was larger to provide
more lift to carry a pilot in lighter winds. The aircraft was flown
frequently up to 300 feet in a single glide. But the aircraft did
not perform as well as the brothers had originally expected. The
aircraft only developed 1/3 of the lift which was predicted by the
Lilienthal data. The brothers modified
the curvature of the wing but this only slightly improved the flying
characteristics. During their test flights the brothers first encountered
wing stalls in which the lift would suddenly decrease and the aircraft would
settle back to earth. They also encountered
an effect known as adverse yaw. On some flights, when the
wings were warped to produce a
roll which should result in a
flight path in the direction
of the lower wing, the drag increased on the upper wing and the
aircraft would twist in the opposite direction. The air speed decreased
and the plane settled back to the ground. At the end of 1901, the
brothers were frustrated and Wilbur remarked that
humans would never learn to fly in his lifetime.
During the winter of 1901, the brothers began to question the
aerodynamic data on which they were basing their designs.
They decided to start over and develop their own data base with which
they would design their aircraft.
a wind tunnel
and began to test their own models.
They developed an ingenious
to compare the performance of
different models. They
over two hundred different wings and airfoil sections
in different combinations to improve the performance of their gliders
The data they obtained more correctly described the flight characteristics which they
observed with their gliders.
By early 1902 the Wrights had developed the most accurate and complete set of aerodynamic
data in the world.
In 1902, they returned to
Kitty Hawk with a new aircraft based on their new data. This aircraft
had roughly the same wing area as the 1901, but it had a longer
wing span and a shorter chord which reduced the drag. It also sported
a new movable
at the rear which was installed to overcome
the adverse yaw problem. The movable rudder was coordinated with
the wing warping to keep the nose of the aircraft pointed into the
curved flight path. With this new aircraft, the brothers completed
flights of over 650 feet and stayed in the air for nearly 30 seconds.
This machine was the first aircraft in
the world that had active controls for all three axis; roll, pitch
and yaw. By the end of 1902,
the brothers had completed over a thousand glides with this aircraft and were the most
experienced pilots in the world. They owned all of the records for
that remained for the first successful airplane was the development
of the propulsion system.
Between 1903 and 1905, the brothers built a series of powered
aircraft which would eventually lead to the first practical airplane.
The Wrights could not find an engine manufacturer who would build
a single engine for them. Their glider flight data indicated that they
needed about 8 horsepower from a 200 pound engine to power their aircraft.
In a period of just six weeks, they built their own gasoline powered, internal combustion
They also designed and built highly efficient aircraft propellers,
using their wind tunnel results and realizing that they must be
shaped as a rotating wing.
In September of 1903, they
returned to Kitty Hawk with their new aircraft. The aircraft was
similar to the 1902 craft with twin wings, twin rudders, and canard
elevators. The plane also carried twin counter-rotating pusher
connected by bicycle chains to the 12 horsepower motor. The pilot
would lie beside the motor on the lower wing. After a number of
frustrating problems with the propeller shafts and transmission
sprockets, they finally made four successful flights on December
17, ranging from a little over 100 feet to over 800 feet. Each of
the flights was marked by an instability in pitch; the nose, and
consequently the entire aircraft, would slowly bounce up and down.
On the last flight, hard contact with the ground broke the front
elevator support and ended the season's flying.
Returning to Dayton, the brothers began work on the 1904
aircraft. They built a new engine similar to the 1903 engine but
with increased horse power by slightly increasing the
(diameter of the piston).
They also built a new airframe which was very similar
to the 1903 aircraft but with redesigned rudders.
In an effort to solve the pitch problem, the brothers moved the radiator
and fuel tank from the front struts to the rear struts and moved
the engine aft to move the aircraft center of
The new aircraft
was flown from a cow pasture owned by Torrence Huffman and located
just outside Dayton. Without the winds of Kitty Hawk, it was a problem
getting enough airspeed to fly. So the brothers devised a catapult
system to help launch the aircraft. Once airborne, the aircraft
experienced the same pitch problems as the 1903 aircraft.
In fact, moving the center of gravity aft had made the performance worse. So the
brothers added 70 pounds of iron bars as ballast
to the front canard to move the center of gravity back farther forward.
With this improvement and the flying skill of the brothers, the aircraft was
able to complete the first circuit of the airfield on September
20, 1904. By the end of the year, the plane could complete four
circuits and stay in the air for five minutes, but the aircraft
still had major performance problems in pitch and was now carrying additional weight.
The brothers were able to solve this final problem by increasing
the size of the elevator and rudder and moving the elevator and
rudder farther from the center of gravity on the new 1905
aircraft. This increased the torque
produced by the control surface and provided greater control for
the aircraft. The radiator and fuel tank were moved back to the
front strut and the size of the fuel tank was increased. The engine
stayed the same as the 1904 aircraft and the weight was decreased
to 860 pounds by eliminating the iron bars. The 1905 aircraft could be
flown until the fuel tank was empty; staying in the air for more
than a half hour, flying nearly 25 miles around Huffman's farm,
executing turns and figure 8's, and flying more than 50 feet off
the ground. The brothers now had a practical working airplane and
began to market it to the War Department.
You can compare the performance of these six aircraft by using an interactive
program located on another page.
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