Between 1900 and 1902, the Wright brothers built and tested a
series of
unpowered aircraft.
The brothers used these aircraft to flight test some of their ideas
concerning the
control
of aircraft, to learn the fundamentals of
aerodynamics,
and to learn to fly.
The aircraft were flown both as kites and as piloted
gliders.
On this slide we show a computerized drawing of the
1900 aircraft being flown as a kite.
The
1900
aircraft was the first large aircraft built by the Wrights.
It was flown repeatedly at Kitty Hawk, North Carolina, during 1900
to verify and demonstrate
roll
control by using
wing warping.
Kitty Hawk was chosen as the flight location because of the steady breeze
which blows in from the Atlantic and because the sand dunes provided a
"soft" landing during crashes and very few "kite-eating" trees.
The kite was flown by several members of the ground crew holding the
Control Lines. The control lines connected to some pulleys and control
wires on the wings. Pulling a control line caused the wing tip on that
side to move, or warp, relative to the rest of the wing. Changing the
shape of the wing tip changes the amount of
lift which that portion of the wing produces.
An imbalance of lift on the wing causes the kite to
roll and move to the side. Controlling the amount of warp allows you to
control the roll of the aircraft.
Here's a picture of 1900 aircraft flown as a kite at Kitty Hawk.
The Wright brothers also flew the
1901
aircraft as a kite. The 1901 aircraft did not
glide
as well as they had
calculated
and the brothers used the information from the kite
experiments to identify and quantify the problem.
Based on the kite results from 1901, the brothers made their
own estimate of the
Smeaton
pressure coefficient, which was the reference condition for all published
aerodynamic data at that time. The Wrights had used the accepted
value of .005 in the design of the 1901 aircraft. But their data indicated
that .0033 was closer to the correct answer. The currently accepted value
of this coefficient is .00327.
Here's a picture of 1901 aircraft flown as a kite at Kitty Hawk.
Note the very high
angle of attack
needed to support the weight of the aircraft.
That's because the aircraft had been designed with "optimistic" data;
the brother were expecting much better performance than they obtained because
the value of the Smeaton coefficient used in the design was too high.
Now compare this flight attitude with this picture of the 1902 aircraft:
The design of the 1902 aircraft had been improved based on
wind tunnel
tests in late 1901. The more
efficient
aircraft flies at a lower angle of
attack.
The brothers also used the more accurate value of the Smeaton coefficient
in this design.
You can compare the performance of these aircraft by using an interactive
performance prediction
program on another page.
The
forces
on an aircraft when flown as a kite are only slightly different from the
forces
on the same aircraft when flown as a glider.
This enabled the Wright brothers to test out the performance of their gliders
by flying them as kites. Modern aircraft fly too fast to be tested as
kites.
But you can learn the same things that Wright brothers learned and in the same way by
flying
your own kite.
It's fun!
Navigation..
- Re-Living the Wright Way
- Beginner's Guide to Aeronautics
- NASA Home Page
- http://www.nasa.gov
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