Question: The Derwitzer Glider was a glider that was developed by Otto Lilienthal, a German pioneer of aviation who became known as the "flying man", and on which date, his glider stalled and he was unable to regain control?
Sentence (from "Derwitzer Glider"): When flown in 1891, it became his a very early successful design able to carry a person and the one of the first successful manned aircraft in the world.
Relevant evidence: No