Otto Lilienthal: The Greatest of the Precursors

Otto Lilienthal aspired to build flying machines at an early age. Born near Ankhlam, Germany in 1848, he along with his brother studied bird flight. At age fourteen, they built a pair of flapping wings and attempted to fly by attaching them to their hands and running downhill by flapping them. By the time of his death in a glider accident in 1896, he was the world’s premier Aeronautical Engineer, having developed and published advanced conceptual understanding of flight data and of flight. The 18th century saw great strides in lighter than air flying and the first successful flight of the Montgolfier brothers. At the close of the eighteenth century, there was technical progress in heavier than air flight. While Sir George Cayley conceived the modern airplane in its basic form as machine with fixed wings, a fuselage and a tail, with separate systems to provide lift, propulsion and control, Otto Lilienthal provided the next quantum leap. Together their combined work provided the basis for the success if the next generation of pioneers.

As teenagers, Otto and his brother Gustav, built fixed wing gliders and tested them at a nearby military field. One of his serious investigations was a full sized Ornithopter, which was suspended by rope and pulleys, counterbalanced by a 40kg weight. The degree to which the pull on the counterweight reduced was measured, when the operator pumped the flapping wings with his legs. Lilienthal attended the Royal Trade Academy where he studied Mechanical Engineering. This prepared him for his future research in aeronautics and provided credibility for his work. He served one year in the Franco-Prussian war and upon return, began his experiments on air pressure with a Whirly arm device.

He measured aerodynamic forces of lift and drag and collected data and is known to have published normal and axial coefficients of aerodynamic force in his air pressure data that was used by future experimenters including the Wright Brothers. After a brief hiatus between 1881 and 1888, Lilienthal returned to the second phase of his career, this time focusing on glider design. He is known to have designed 16 different gliders based on his aerodynamic calculations and made as many as 2000 short flights. Lilienthal is credited with being the first pilot to recognize, attempt and achieve soaring flight. Lilienthal practiced gliding flight from a hill in his many designs. He published his experiments, encouraging and urging his readers to be unafraid to try gliding and to improve on his designs. Lilienthal flew with his arms inserted into the sleeve of the glider, elbows flexed and supporting his upper body, while his lower body hung below.

Otto Lilienthal flying from a hill

On the fatal day in August 1896, while trying to steer in a heat eddy, he encountered trouble and fell nose first to the ground unable to re-establish flight. Although he was pulled alive from the wreckage, he suffered concussions and is assumed to have perished from the growing intracranial hematoma. Otto Lilienthal knew that to build a successful aircraft, it was essential to learn to fly. He became the first to fly a glider and the first fatality of flight in 1896. He is also known for his extensive tests of airfoils. He is also known for his contribution to Kutta’s first paper on airfoil theory. He inspired other followers such as Percy Pilcer, Octave Chanute, Ferdinand Ferber and the Wrights. In Germany, where it almost began, Otto Lilienthal is considered one of the strongest pioneers of the German aerospace. He was the immediate predecessor of the Wrights and is undoubtedly one of the greatest precursors for his daring and tenacious pursuit of flying.

See Also:

To Fly Like a Bird

Lilienthal Glider