This page shows a computer drawing of the Wright
brothers' 1901 aircraft. This was the second
unpowered
aircraft built by the brothers.
The aircraft was flown repeatedly at Kitty
Hawk, North Carolina, during 1901 as a piloted
glider
and as a
kite.
The Wright brothers used this aircraft to further investigate the
fundamentals of aerodynamics
which they had begun in 1900. You can
learn the same things in the same way by flying
your own kite or glider.
It's fun!
You can study the design of the 1901 aircraft by changing the
view using the buttons at the
bottom of this Java program.
You can download your own copy of this applet by pushing the following button:
The program is downloaded in .zip format. You must save the file to disk and
then "Extract" the files. Click on
"1901.html" to run the program off-line.
Here are two photo's taken in 1901 of the actual aircraft flying at
Kitty Hawk.
The 1901 aircraft was larger than the 1900
aircraft, but of the same basic design; it
has two wings, no tail, and an elevator/stabilizer mounted in the
front of the aircraft.
The wing span
was increased from 17.5 to 22 feet and the
chord
(front edge of wing to back edge) was changed from 5 to 7 feet,
making the overall wing area increase from 165 square feet to 290
square feet. The intent was to provide more
lift
so they could pilot
their glider in winds of less velocity. Without the pilot, the 1901
craft weighed about a hundred pounds.
The pilot would lie on the bottom wing
and control the roll of the aircraft by using
a foot pedal. The pedal is connected to wires which pull on the wing
tips and warp, or
twist, the wing. Warping produces unequal forces on the wings
which would rolls the aircraft. On the
1901 aircraft, the pilot could also change the shape of the elevator
to control the up/down position of the nose of the aircraft. This is
called the pitch of the
aircraft.
The aircraft was flown frequently up to 300
feet in a single
glide,
but it 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
lift equation
using the data published by the German, Otto Lilienthal. Lilienthal
was the world's foremost authority on
aeronautics and had died in a glider accident in 1897. The brothers installed
additional struts on the lower wing to alter the camber (curve) of
the aircraft wing in an effort to improve the flying
characteristics.
In this photo of the aircraft, taken immediately
after landing, you can see the additional struts between the wings at
the center.
During their test flights the brothers encountered an effect known
as adverse yaw. On some flights, when the wings were warped to
produce a roll which should have resulted in a
curving
flight path in the direction of the lower wing, the increased
drag
on the upper wing twisting in the opposite direction caused the
air speed to decrease and the plane to settle back and turn into the
ground. In one of these crashes Wilbur was thrown into the elevator,
banged about, and ended up with bruises and a black eye. After that
they only flew this craft as a kite.
By the end of 1901 flying season, the
brothers were frustrated and Wilbur remarked that
humans would not learn to fly in his lifetime. Aeronautic pioneer
Octave Chanute asked Wilbur to give a lecture about their experiments
to a meeting of the Western Society of Engineers. After the talk
Chanute convinced Wilbur that they must continue, as no one else at
the time had near the grasp of the principles of flying as he and
Orville .
When Wilbur returned to Dayton, the brothers
suspected that the lift data from Lilienthal might not be correct.
To
test
this idea, they fastened a bicycle wheel horizontally to the
front of a bicycle, placed an airfoil shape and a flat plate on
opposite sides, and rode off to create wind. The angle at which the
wing had to be placed to balance the plate was far from that
predicted by Lilienthal.
At this point they decided they needed to
gather their
own data.
They constructed their own wind
tunnel with both
lift
and
drag
balances
made out of old hacksaw blades and bicycle spokes. It took them a
month to develop a smooth air flow, and over the period of the next
two months they
tested
over 200 small wings of different shapes and
sizes and in different combinations.
Fifty of the configurations were subjected to careful
parametric studies. The
results
were another Wright
brother first - the first real usable and accurate aerodynamic data
obtained by experimenting with a wind tunnel. These results
would be applied to the 1902
aircraft, which would answer many of the questions raised by the
1901 aircraft as they progressed toward the
successful 1903 flyer.
Activities:
You can build your own model of the 1901 Wright aircraft using a styrofoam
meat tray and some toothpicks.
Plans for this model are available
with step by step instructions. The final model looks like this:
