Geiger was born on 6 May 1920 in Überlingen, near Lake Constance, which was part of the Republic of Baden during the Weimar Republic. He was the son of a typographer. After graduation from school and receipt of his Abitur, Geiger joined the Luftwaffe on 15 November 1939 as a Fahnenjunker. Following flight training, he was promoted to Leutnant on 1 April 1941.
World War II
World War II in Europe had begun on Friday, 1 September 1939, when German forces invaded Poland. Following the 1939 aerial Battle of the Heligoland Bight, Royal Air Force attacks shifted to the cover of darkness, initiating the Defence of the Reich campaign. By mid-1940, GeneralmajorJosef Kammhuber had established a night air defense system dubbed the Kammhuber Line. It consisted of a series of control sectors equipped with radars and searchlights and an associated night fighter. Each sector named a Himmelbett would direct the night fighter into visual range with target bombers. In 1941, the Luftwaffe started equipping night fighters with airborne radar such as the Lichtenstein radar. This airborne radar did not come into general use until early 1942.
Night fighter career
In mid-1941, Geiger was posted as to 8. Staffel of Nachtjagdgeschwader 1. He claimed his first aerial victory on 9 July 1941 over a Handley Page Halifax bomber shot down south of Nijmegen at 23:32. He received the Honor Goblet of the Luftwaffe on 19 October 1942. On 1 March 1943, Geiger shot down a Halifax bomber from No. 35 Squadron with an almost intact H2Sground scanning radar system. This allowed the Germans to analyze the radar which led to the development of the FuG 350 Naxos radar detector, which allowed the night fighters to home on to the H2S emitting signals. On the night of 29/30 March 1943, Geiger became an "ace-in-a-day" taking his total to 21 aerial victories. That night he claimed one Halifax, two Vickers Wellington and three Avro Lancaster bombers. One of his victims was Lancaster ED391, of No. 460 Squadron RAAF. Flight Sergeant David Harold Victor Harlick and his crew died. He was promoted to Oberleutnant on 1 April. On 1 May 1943 Geiger downed Halifax DT471 of 405 Maritime Patrol Squadron flown by H P Atkinson. Atkinson, and one other crewmember died. Geiger was decorated with the Knight's Cross of the Iron Cross on 22 May 1943, the nomination had been submitted for 26 aerial victories claimed earlier. The presentation was made by Generalmajor Kammhuber. On 1 July, he was promoted to Hauptmann and received the German Cross in Gold on 31 August 1943. That night Geiger claimed his 44th victory over Stirling EH961 from No. 196 Squadron RAF. Sergeant J. Griffiths and two other members of the seven man crew were killed. Crew member and gunner Sergeant C P Pierce was among the youngest fatalities in the RCAF in 1943, aged 18. On 29 September 1943, Geiger was shot down by the Bristol Beaufighter VI of Wing commanderBob Braham of No. 141 Squadron RAF over the Zuiderzee, Netherlands. Geiger and his radio operator Feldwebel Dieter Koch managed to bail out of their Messerschmitt Bf 110 G-4, but both drowned. On 2 March 1944, Geiger was posthumously awarded the Knight's Cross of the Iron Cross with Oak Leaves, the 416th officer or soldier of the Wehrmacht so honored. He was buried at the German war cemeteryYsselsteyn in the Netherlands.
Summary of career
Aerial victory claims
Foreman, Parry and Matthews, authors of Luftwaffe Night Fighter Claims 1939 – 1945, researched the German Federal Archives and found records for 51 nocturnal victory claims. Matthews and Foreman also published Luftwaffe Aces — Biographies and Victory Claims, listing Geiger with 48 claims, plus two further unconfirmed claims.