may 24th 1848 in Anklam (Pomerania), Otto Lilienthal
is without any doubts, one of the patriarch of modern aviation.
Like many of those "flying fools" who gave wings to the world,
he was fascinated early in life by human flight. At the young
age of sixteen, he conducted experiments with large rudimentary
gliders (at night), with the help of his Brother Gustav. As many
other precursors of his era, he became interested in "flopping
wings", and after graduating as an engineer, he published in 1889
a fundamental work for the future of aviation: "Der Vogelflug
als Grunglage der Fliegenkuntst" (The flight of the birds as a
basis for the art of flight). It was a work that would later on
in life echo important theories about flying. As Marey, Lilienthal
was interested by the flight of the birds, and as the unfortunate
Mouillard, he was one of the firsts to demonstrate the importance
of the wing's camber.
Lilienthal had understood, long before many of his contemporaries,
that flight stability would be achieved with a cambered airfoil
wing. This fact however was not the only discovery in his studies.
It became evident to Lilienthal, that a flying machine would be
useless, if it could not be controlled. Going against the consensus
of the era, he did not believe in power flight, preferring to
pursue his experiments with gliders.
"Let's learn about the science of flight, let's learn how to fly,
let's experiment and perfect gliders; powered flight will follow
later on." This statement is without any doubts how we can summarize
Lilienthal's philosophy about flying.
The following statement was written in his own words:
"During free flight in the air mass, there are many phenomena
never encountered elsewhere; particularly those related to the
wind, and which must be considered in the construction, and in
the utilization of the flying machines….The only possibility for
a rapid solution to human flight must be a systematic approach
by experimenting with "real time" flight."
Obsessed with experimentation, Otto Lilienthal did not rely on
empirical theories, and his machines were the results of many
computations. His working method would later on bring major contributions
to aeronautical science, and permitted him to produce very sophisticated
gliders despite their rudimentary appearance. All his gliders
were built with a structure made either of bamboo or rattan, and
covered with cotton linen. (During this time period, we were still
a long way of utilizing carbon fiber and synthetic materials).
The plans for all his flying machines, (aboard which he performed
over two thousand gliding flights) are basically the same.
Mainly, Lilienthal built monoplanes with a wingspan of about seven
meters, on which he suspended himself with his elbows and forearms.
Whereas other precursors such as Langley, or Ader pursued the
construction of machines capable of only a few bounces in the
air with no maneuvering capabilities, Lilienthal was able to modify
his trajectory, by turning, and even sometimes attaining an altitude
greater than his "takeoff" point. In fact, he was developing airplane
control (pilotage), neglected by his peers.
After performing some "planements" (meaning gliding flights, a
term used in that era), in Werder and in Steglitz, Lilienthal
had a special, artificial conic hill built in Lichterfelde, in
the Berlin suburbs. From there, he could always find favorable
winds to perform his glides. He also invented a small carbonic
acid motor, with which he could control the wing's extremities,
somewhat as the birds do with their feathers, but he would never
have the time to experiment this idea.
To reduce the wingspan of his gliders, he began building biplanes
that would have eventually used this concept. Unfortunately, on
August 9th 1886, the top wing of his latest prototype
broke off, and Lilienthal fell from a height of 17 meters. He
died shortly thereafter of his wounds after uttering his last
words: "Opfer müssen gebracht werden!" roughly meaning: "Victims
are necessary", or "Sacrifices must be made."
Lilienthal's work and experiments had a deep impact on his contemporaries;
in particular with Chanute and the Wright Brothers. Lilienthal
is not only one of the Father of aviation, he invented piloting,
the controlling of aircraft. In any case, he was the first man
to have maneuvered in flight, an "heavier than air" machine.
Otto Lilienthal is not only an important person in aviation's
history, he was also preoccupied with social progress, especially
with the employees of his factory. Technical progress of his era
was also one of his subjects of research; he had worked on a small
steam engine designed for craftsmanship. Surprisingly, one of
his inventions survives him to this day all over the world: the
wood blocks construction set. Certain "Ankersteinbaukasten"
models have not change in a century!