Mayer was born on 5 December 1917 in
Fürth, at the time in
Kingdom of Bavaria as part of the
German Empire. World War II in Europe began on Friday 1 September 1939 when German forces invaded Poland. In January 1942, Mayer was transferred from the
Ergänzungs-Jagdgruppe West, a supplementary training unit for fighter pilots destined to fight on the
Western Front, to 6.
Staffel of
Jagdgeschwader 26 "Schlageter" (JG 26—26th Fighter Wing), a squadron of the II.
Gruppe. Mayer made four
touch-and-go flights on the
Focke-Wulf Fw 190 on 26 January, his first on the Fw 190. At the time, II.
Gruppe was based at
Abbeville-Drucat Airfield and commanded by
Hauptmann Joachim Müncheberg while 6.
Staffel was headed by
Oberleutnant Otto Behrens. fighter similar to those flown by Mayer. On 12 February, Mayer participated in
Operation Donnerkeil, flying on two combat missions with II.
Gruppe, without claiming an aerial victory. The objective of this operation was to give the German
battleships and and the
heavy cruiser fighter protection in the breakout from
Brest to Germany. The
Channel Dash operation (11–13 February 1942) by the
Kriegsmarine was codenamed Operation Cerberus by the Germans. In support of this, the Luftwaffe, formulated an
air superiority plan dubbed Operation Donnerkeil for the protection of the three German capital ships. Mayer's Fw 190 A-2 (
Werknummer 5393—factory number) suffered engine failure on 15 July resulting in a
forced landing at Abbeville-Drucat Airfield. He claimed his first aerial victory on 31 July 1942 in defense of a
Royal Air Force (RAF)
"Circus" mission flown by twelve
Douglas Boston bombers supported by the
North Weald Wing. "Circus" No. 201 had targeted the airfield at Drucat and withdrew over the
Somme Estuary when they were intercepted by II.
Gruppe fighters. In this encounter, Mayer claimed a
Supermarine Spitfire fighter, from either
No. 121 or
No. 332 Squadron, shot down over the
English Channel. This claim was not confirmed. In late August, Mayer filed claims for two further Spitfires shot down, both were also not confirmed. Depending on source, the first was either claimed on 26 or 27 August over the Somme Estuary. The second, on 28 August, was over a
Royal Canadian Air Force (RCAF) Spitfire from
No. 401 Squadron. On 6 September, the
United States Army Air Forces (USAAF) targeted the airfield at
Wizernes with a small formation of
Boeing B-17 Flying Fortress bombers. Mayer claimed a B-17 shot down at 18:45 which was not confirmed again. Mayer first confirmed claim was on 14 March 1943. The RAF conducted a "
Rodeo" fighter sweep by the
Biggin Hill Wing to
Le Touquet. II.
Gruppe, under command of
Hauptmann Wilhelm-Ferdinand Galland, intercepted the RAF fighters and claimed five aerial victories including a Spitfire shot down by Mayer over the Somme Estuary. On 4 April,
Western Allies aerial forces attacked the
Renault factory near Paris. Defending against this attack, Mayer claimed yet another unconfirmed aerial victory. The claim was made over a Spitfire presumably shot down northwest of
Dieppe.
Defense of the Reich On 29 April 1943, the USAAF flew its largest mission to date, sweeping the Dutch coast from
Ostend to
Woensdrecht. Led by
Major Josef Priller, 6. and 8.
Staffel intercepted
Republic P-47 Thunderbolt fighters off the coast. During the encounter, Mayer shot down a P-47 fighter from the
56th Fighter Group north of Ostend. On 13 June, Mayer shot down a P-47 from the
78th Fighter Group north-northwest of
Dunkirk. That day, the
VIII Bomber Command flew a mission to
Kiel and
Bremen. He was credited with his first aerial victory over a heavy bomber in
Defense of the Reich on 22 June during the
Battle of the Ruhr. The claim was made over a B-17 bomber from the
381st Bombardment Group or
384th Bombardment Group as a
Herausschuss (separation shot) near
Antwerp. A
Herausschuss was a severely damaged heavy bomber forced to separate from its
combat box which normally was counted as an aerial victory. On 30 July 1943, Mayer was wounded and made a forced landing northeast of
Emmerich in his Fw 190 A-5 (
Werknummer 57222) following combat with a B-17 bomber. On 3 September, Mayer was credited with another
Herausschuss over a B-17 bomber near
Melun on its mission to bomb Paris. The B-17 belonged to either the 381st Bombardment Group or the 384th Bombardment Group. Shortly after, he claimed a P-47 from the 56th Fighter Group shot down near
Creil. This claim was not confirmed. On 18 February 1944, the RAF flew
Operation Jericho, a low-level
bombing raid, on the
Amiens Prison in
German-occupied France. The objective of the raid was to free
French Resistance and
political prisoners. The attack force of nineteen
de Havilland Mosquito bombers was escorted by eight
Hawker Typhoon fighters from
No. 174 Squadron. At 11:35, Luftwaffe fighters were
scrambled from
Grévillers. Following the bomb run by the Mosquitos, the commanding officer of the operation,
Group Captain Percy Charles Pickard of the
No. 140 Wing, circled the target to assess the result of the operation. Pickard was attacked by Mayer and shot down at 12:05, killing him and his navigator
Flight Lieutenant John Alan Broadley. Mayer was transferred on 31 March, becoming a flight instructor. During his tour as an instructor, he was awarded the
German Cross in Gold () for 15 aerial victories on 16 April. Mayer returned to II.
Gruppe in August and was assigned to 5.
Staffel. Mayer claimed his first aerial victory following his tour as an instructor on 18 August during the
Battle of the Falaise Pocket. A
pocket had been formed around
Falaise, Calvados, in which the German
Army Group B, with the
7th Army and the
Fifth Panzer Army (formerly ) were encircled by the Western Allies following the
Normandy landings on 6 June. Flying multiple missions in support of the encircled German forces, Mayer shot down a
North American P-51 Mustang from the
No. 315 Polish Fighter Squadron and a P-47 fighter near
Beauvais. On 25 August, the day
Paris was liberated, the USAAF
Ninth Air Force attempted to eliminate the remaining German fighter forces in France. Defending against this attack, Mayer shot down a
354th Fighter Group P-51 near
Saint-Quentin. On 17 September 1944, Allied forces launched
Operation Market Garden, the operation to secure a bridgehead over the River Rhine. Two days later,
II. Jagdkorps dispatched 148 fighters to the combat area. Mayer was credited with shooting down two P-51 fighters near
Nijmegen that day, taking his total to 20 aerial victories. On 23 September, the Allies flew resupplies to the combat area around
Arnhem. The transport aircraft were protected by 519 fighters from the
VIII Fighter Command and 40
Lockheed P-38 Lightning fighters from the Ninth Air Force. German fighters dispatched by
Luftflotte Reich never reached the transports. Over
Goch, II.
Gruppe intercepted a flight P-51 fighters from the
352nd Fighter Group. For the loss of one of their own, II.
Gruppe shot down four P-51 fighters, including one by Mayer. On 27 September, Mayer shot down a RCAF
No. 412 Squadron Spitfire over the airfield at
Kirchhellen. This is last known aerial victory claimed by a pilot of JG 26 to have been fully confirmed by the
Ministry of Aviation ().
Squadron leader and death On 22 October, the
Staffelkapitän (squadron leader) of 8.
Staffel,
Oberleutnant Karl-Wilhelm Hofmann, was injured in a ground accident. Although he continued flying combat missions, temporarily, command of his 8.
Staffel was passed on to Mayer as
Staffelführer (acting squadron leader). Mayer claimed his last two aerial victories on 19 November in combat with the RCAF No. 412 Squadron. Spitfires from No. 412 Squadron were attacking a bridge at
Veen in the Netherlands when they came under attack by Fw 190s from II.
Gruppe. In this encounter, Mayer claimed two Spitfires shot down north of Kirchhellen. Mayer was
killed in action on 4 January 1945. Officially a member of 5.
Staffel, Mayer led a flight from 8.
Staffel on mission from the airfield at
Nordhorn. Shortly after takeoff, the flight came under attack by Spitfires from the RCAF
No. 442 Squadron. In this encounter, Mayer was shot down in his Fw 190 D-9 (
Werknummer 500052) near
Lohnerbruch. Mayer's inseparable friend
Heinz-Gerhard Vogt, commander of 5.
Staffel, was killed in action ten days later. Posthumously, he was awarded the
Knight's Cross of the Iron Cross () on 12 March 1945. ==Summary of career==