Career
Arntzen flew as an observer with two artillery cooperation units during 1916, Future Farmers of America 34 and Future Farmers of America 2. He scored four victories with the latter unit, though details are sketchy. He then underwent pilot training and was assigned to Royal Prussian Jagdstaffel 15 as both pilot and technical officer
On 13 August 1917, he shot down a Caudron to become an ace.
On 15 October 1917, he shot down a French observation balloon. On 13 January 1918, he was promoted to command of Royal Prussian Jagdstaffel 50.
On 27 May 1918, his career as a balloon buster ended with his being wounded by anti-aircraft fire while attacking one.
