19 February 1916|
Königsberg (Neumark) (now Chojna)
|Died||April 23, 1943
|Years of service||1935–1943|
|Awards||Iron Cross, 2nd class|
|Relations||John Fiehn (brother)|
He was born on 19 February 1916 in Königsberg, Germany. In 1935 he joined the German military as a trainee in the Luftwaffe, where he rose to the rank of Oberleutnant in 1939. At the outbreak of the war, Fiehn transferred to the Kriegsmarine where he was given the rank of Kapitänleutnant and awarded the Iron Cross 2nd Class. In 1942 he was given commission of U-191. After departing form Bergen on 17 March 1943, U-191 was attacked and destroyed by HMS Hesperus, and Fiehn died along with the entire crew on 23 April 1943.
- Busch, Rainer; Röll, Hans-Joachim (1996). Die deutschen U-Boot-Kommandanten [The German U-Boat Commanders]. Der U-Boot-Krieg 1939–1945 (in German). I. Hamburg, Berlin, Bonn, Germany: E.S. Mittler & Sohn. ISBN 978-3-8132-0490-2.
- Helgason, Guðmundur. "Kapitänleutnant Helmut Fiehn". German U-boats of WWII - uboat.net. Retrieved 24 July 2016.