Brunner was born on 17 July 1918 in Dörtel, present-day part of Bad Mergentheim, at the time in the Kingdom of Württemberg within the German Empire.

The Staffel was based at an airfield at Petsamo, present-day Pechenga in Murmansk Oblast, Soviet Union on the Eismeerfront (Ice Sea Front)—the area of operations nearest the Arctic Ocean.

[14] On 4 April, following aerial combat with Bell P-39 Airacobra fighters, Brunner made a crash landing in his Bf 109 G-2 (Werknummer 13923).

[15] Following these events, he was picked up by Oberfeldwebel Rudolf Müller who flew back to Petsamo and returned with a Fieseler Fi 156 Storch.

His opponents belonged to 769 IAP PVO (Fighter Aviation Regiment—Istrebitelny Aviatsionny Polk; Home Air Defense—Prozivo-Vozdushnaya Oborona), which reported three P-40s lost.

Following combat with P-39s, he was forced to bail out of his Bf 109 G-2 (Werknummer 14802) approximately 2 kilometers (1.2 miles) southwest of Groß Venedigerberg, a German name for a hill east of Pechenga.

Gruppe had taken off at 03:25 to escort eight Ju 88 bombers and ten Messerschmitt Bf 110 and Focke-Wulf Fw 190 ground-attack aircraft on a mission to Murmansk.

At approximately 04:00, a Luftwaffe flight of Bf 109s engaged in aerial combat with six P-39s from 2 GvSAP (Guards Composite Aviation Regiment—Gvardeyskiy Smeshannyy Aviatsionnyy Polk).

His body was recovered by the infantry and buried at the German war cemetery Petschenga-Parkkina, located approximately 60 kilometers (37 miles) southeast of Kirkenes.