By Kip Tabb | Outer Banks Voice on July 27, 2021
When Kitty Hawk Kites hang gliding instructor Michael Vaughn had the chance to fly the Lilienthal glider that Markus Raffel brought from Germany, he didn’t hesitate.
“It was a once in a lifetime experience,” he said. Raffel had just flown the glider. And Vaughn’s father, hang gliding school assistant manager Billy Vaughn, had taken a turn when Raffel asked who else wanted to fly. “I couldn’t say yes fast enough,” he said.
The Wright Brothers were certainly the first to make a powered flight, and to re-create that flight time and time again while controlling their aircraft. Their wing warping control of their gliders and airplanes was truly unique at the dawn of the 20th century. They were, also, pioneers in propeller design.
But one thing they were not the first to do was to build a glider that could lift a human into the air and land that person safely. That distinction belongs to German engineer and inventor Otto Lilienthal.
Lilienthal did not have just one successful flight. He, in fact, flew over 2,000 times and held a number of patents for his glider designs. In 1896 at age 48, however, he made his final flight as his glider went into a stall at 50 feet and crashed, breaking the aeronautical pioneer’s back. He died 36 hours after the accident.
As a consequence, Lilienthal’s contributions to the science of flight are often seen as important but flawed, a circumstance Raffel feels is unfair and unwarranted.
Earlier this month, he brought a replica of one of Lilienthal’s gliders to Jockey’s Ridge State Park. Working with hang gliding instructors and flying it himself, Lilienthal’s glider once again took flight.
When he’s not on the dunes of Jockey’s Ridge or in California, Raffel is Professor Dr. Markus Raffel, the Head of the Helicopter Department at the German Aerospace Center, Institute of Aerodynamics and Flow Technology in Göttingen, Germany. His area of expertise is in airfoil design and fluid dynamics.
But when he is not immersed in algorithms and computational math, he is trying to bring to light the contributions Lilienthal made to aviation. There may not be an exact date when Raffel’s work with the Lilienthal glider began, but 2016 at the National Air and Space Museum in Washington, DC is a good place to start.
“The curator there is John D. Anderson…who wrote many books on the history of flight and the history of aerodynamics,” he said. “He made it very clear that Lilienthalenthal was right.”
But when Raffel was on the floor of the museum, he heard a different story.
“There was a tour guide telling the kids in the Wright’s room where the Wright Flyer was [that] there was another one who tried flying. His name was Otto Lilienthal. He crashed and died, so he was wrong and the brothers were right. And I found it embarrassing somehow,” he said.
There is a misconception about Lilienthal’s calculations, that they were wrong, and that the Wright Brothers had rejected them.
But, as Raffel explains, the Wright Brothers didn’t so much reject his calculations as they further refined them and made them more precise and better suited for their purposes.
Raffel points to an article the older brother wrote lauding the German aviator’s contributions.
“Wilbur Wright wrote an article in 1912 where he said Lilienthal was just wonderful and the world owes him a great debt, and he was the greatest precursor,” he said.
It was not just the article Wilbur wrote that tells of the respect they had for Lilienthal.
“In 1910 they gave a $1,000 check to the widow,” Raffel added. That would be around $28,000 in 2021.
The glider that Vaughn and Raffel flew is an exact replica of a Lilienthal monoplane glider, the measurements and material used gleaned from the glider at the National Air and Space Museum and a glider at the Deutches Museum in Munich. The willow struts and spars were what Lilienthal used. Linen was specially loomed to match the fabric of the original — and tests had shown that the glider should be able to fly.
Germany was celebrating the 125th anniversary of human flight in 2016, commemorating Lilienthal’s 1891 first gliding experiments and 21st century tests were used to assess the design.
“They made a one-to-one replica and had this in the largest European wind tunnel and proved for the very first time that this had longitudinal static stability. Meaning, if you have the right positioning in the glider, you fly steadily down without any control,” Raffel said.
That is the same criteria that hang gliding pilots use to determine how well their glider flies —hands off the control bar and the glider will fly in a predictable path to the ground.
But the real test was flying the replica. And that was an unforgettable experience.
“When I first flew freely that was overwhelming…that was just wonderful. I was the first one in one hundred and twenty-five years to fly this thing,” Raffel said.
Like Raffel, Vaughn understood the significance of flying an aircraft that had not lifted above the ground for more than a century.
“I am so privileged to have had the opportunity to do it. Including Lilienthal himself, it was him and then Marcus…and Billy (Vaughn) and I am number four to have ever flown that glider,” he said.