John A. Karch was a 27-year-old teacher from Mt. Vernon, Illinois, when the enlisted in the U.S. Army on 12 December 1917. He attended the U.S. School of Military Aeronautics at the University of Texas in Austin, Texas, as a cadet pilot and graduated on 4 May 1918. He arrived at Rich Field, Waco, Texas, for flight training on 3 June 1918. He flew biplanes and the Curtis JN-4D Jenny. Shortly after the end of WWI on 11 November 1918, he was discharged from the Army Air Service.
These collar insignia were worn on the stand-up collar of his olive drab tunic or service coat. The left pin is the signal corps device and the right is the air corps device.