He was at Armee-Flug-Park (Army Flight Park) 9 when he received his first operational assignment; on 8 January 1918, he was posted to Feldflieger Abteilung (Field Flier Detachment) 42.

Beginning 3 July 1918, Bormann was credited with downing 17 enemy aircraft, most of them fighters, by 4 November 1918.

[2][3] Ernst Bormann was a flying instructor from 1 August 1925 to 30 September 1930, at the nascent Luftwaffe's covert aviation training center at Lipetsk, the Soviet Union.

In 1934, after Hitler's rise to power, Bormann was commissioned as a captain in the Luftwaffe.

[4] His next assignment was the command of Lehrgeschwader (Advanced Training Wing) 1; this posting lasted until July 1940.