d. First helicopter [manned]
Thursday, February 05, 1924 11:31:
10 AM
Sergey Vasil'yevich Rachmaninov hovering out of ground effect in the Sopwith Camelot.
c. First helicopter [unmanned]
Thursday, February 05, 1924 11:31:
13 AM
Just after Sergey Vasil'yevich Rachmaninov had jumped out of the Sopwith Camelot.