When i was in school in germany i was taught he laid the foundation for our modern flight-technology. Now i came to understand for example american schools value the Wright brothers far higher. How true is this? How important was he really?
Finally. An askhistorians post I can answer!
I recently finished reading the book "Wittgenstein flies a kite"
The books discusses the engineering marvels of sound recording and flight, and how that may have influenced the notoriously brilliant Austrian philosopher Ludwig Wittgenstein.
In the preface, Susan G. Sterret (the author), talks about the history of the Wright brothers.
She specifically states that it was not until Otto's successfull gliding, and the important part of that being his controlled heavier than air flight that reminded the Wright brothers of a helicopter toy they had as children.
Sterret gives auxialliary sources of Wright brother biographies that confirm they were swayed by Otto's success, and I would love to tell you them, but it was a library book I'm no longer in possession of.
In America (and Canada) we are taught about the Wright brothers, not about Otto, and, truthfully, the Wright brothers were the first doing controlled heavier than air flight, however they would not and could not have done so without Otto's controlled gliding.
Whoever you choose to credit flight to, both of these (all three technically) figures were important and made distinct technical advances that gave us controlled heavier than air flight.
Sources: Wittgenstein flies a kite - Susan G Sterrett