<Li> Flettner Fl 265 (twin rotor liaison - observation helicopter, pioneer of synchropter configuration) </Li> <Li> Flettner Fl 282A / B "Kolibri" (reconnaissance synchropter) </Li> <Li> Flettner Fl 339 (reconnaissance helicopter) </Li> <Li> Nagler - Rolz NR 54 (one - man portable helicopter) </Li>

When was the first helicopter used in the military