Theodore von Karman ...

[retread]

..... one of the great minds of the twentieth century and perhaps the greatest single influence in aerodynamics served in the Austrian-Hungarian Army from 1915-1918. At some point during this period he was appointed as the head of research for the A/H Air Service and developed a tethered helicoptor which I believe did not pass the developmental stage.
Information regarding von Karman's wartime years seems sparse. Is anyone aware of of a more detailed description of his Great War service or a source which provides more background during this period.
Thanks.