The son of a cavalry officer, Heinrich Gontermann joined the 6th Uhlan Cavalry Regiment in August 1914. Serving at the Front, he was wounded in action in September 1914. He was promoted to Leutnant in the spring of 1915 and awarded the Iron Cross, second class. Having been transferred to the 80th Fusilier Regiment in October 1915, Gontermann's application for transfer to the air service was accepted and he completed pilot training in early 1916. After flying the Roland C.II with Kampfstaffel Tergnier and the AGO C.I with FA 25, he was sent to Jastaschule, graduating on 11 November 1916. Posted to Jasta 5, he scored his first victory on 14 November 1916. On 5 March 1917 he was awarded the Iron Cross, first class. By the end of April 1917 he had downed 17 enemy aircraft and was made Staffelführer of Jasta 15. With this unit he bagged 22 more victories. On 30 October 1917, while testing a new Fokker DR.I (115/17), Gontermann was fatally injured in a crash when the upper wing failed.
Prior to his death, Gontermann scored 18 victories against Allied balloons. On the evening of 19 August 1917 he shot down four of them in three minutes.