

World War II in Europe began on Friday 1 September 1939 when German forces invaded Poland. Zwernemanns’ service with 7. Staffel (7th squadron) of Jagdgeschwader 52 under command of Major Hubertus Merhardt von Bernegg began, on 01-03-1940 and participated in the Battle of France. He claimed his first aerial victory over a Supermarine Spitfire in July 1940. In May 1941 he fought in the Battle of Crete.
With the beginning of Operation Barbarossa
, the invasion of the Soviet Union, his tally increased, and he became one of the most successful pilots of his Jagdgruppe. By the end of 1941 his score stood at twenty and he was awarded
on 12-12-1941. In May 1942 the number of victories had increased to thirty and he was honored with the German Cross in Gold on 25-05-1942
The Oberfeldwebel received the Knight’s Cross of the Iron Cross for 57 victories on 23-06-1942. In the month of September 1942 he claimed over thirty victories. On 01-10-1942 claimed four victories increasing his score to 103, for which he received the Oak Leaves to the Knight’s Cross.
He was the 26th Luftwaffe pilot to achieve the century mark.
He was promoted to Leutnant in the spring of 1943. One of Zwernemanns’ wingmen and students was history’s top-scoring ace Erich”Bubi” Hartmann.
While serving with 9./JG 52, under command of Oberstleutnant Dietrich Hrabak
Zwernemann claimed his 113th victory on 15-04-1943 and victory 117 on 07-05-1943. One of his victories on 15-04-1943 was against Starshiy Leytenant Dmitriy Glinka,
who had already been recommended to be appointed a Hero of the Soviet Union. At the end of May 1943 he was posted to the fighter pilot training school, Ergänzungsgruppe Ost. He returned to combat service in the fall of 1943, this time serving with 3./Jagdgeschwader 77
under command of Oberstleutnant Johannes Steinhoff,
in Italy.
In November 1943, Zwernemann was transferred to Defense of the Reich duties in Germany. On 15-12-1943, he was posted to 1. Staffel of Jagdgeschwader 11 under command of Major Anton “Toni” Hackl
, which at the time was based at Husum airfield. Anton Hackl survived the war and died on 09-07-1984, age 69, in Regensburg. There, Zwerneman initially served as acting Staffelführer (squadron leader), representing Hauptmann. Siegfried Simsch,
before officially being appointed Staffelkapitän of 1. Staffel on 08-02-1944. Siegfried Simsch was shot down in an airfight, age 31 on 08-06-1944 bei Rennes . Zwernemann claimed his first aerial victory in this theater of operations on 10-02-1944. That day, the United States Army Air Forces (USAAF)
targeted Braunschweig with 169 Boeing B-17 Flying Fortress bombers
from the 3rd Bombardment Division
. The primary objective were the Luther-Werke,
a mechanical engineering company, and the repair facilities at Waggum. The bombers were escorted by 466 fighter aircraft. Zwernemann claimed the destruction of a Lockheed P-38 Lightning fighter that day. In total, the Luftwaffe claimed 51 aerial victories, including 32 four-engine bombers while the USAAF reported the loss of 30 four-engine bombers and eleven escort fighters.
Death and burial ground of Zwerneman, Josef, “Jupp”.



On 08-04-1944, the Eighth Air Force, “The Mighty Eighth” again targeted Braunschweig as well as various Luftwaffe airfields in northwestern Germany and the Netherlands. In total the USAAF 664 four-engine bombers, escorted by 780 fighters, including 206 North American P-51 Mustangs, were intercepted by 20 Luftwaffe fighter groups. In this encounter, the Luftwaffe claimed 87 aerial victories, including 65 four-engine bombers. This figure includes a B-24 bomber and a P-51 fighter claimed shot down by Zwernemann taking his total to 126 aerial victories. Following this encounter, the USAAF reported the loss of 36 four-engine bombers and 25 escort fighters and claimed at least 158 Luftwaffe aircraft shot down plus further 55 destroyed on the ground. In total the Luftwaffe lost 78 aircraft destroyed, 42 pilots killed in action plus further 13 wounded. Among those pilots killed in action was Zwernemann who was shot down in his Focke-Wulf Fw 190 A-7/R6 (Werknummer 431164—factory number)
near Gardelegen, Altmark. His comrades, including Oberleutnant Fritz Engau
from 2. Staffel, reported that Zwernemann had bailed out but was shot in his parachute by a P-51 pilot. Jupp Zwernemann, age 28, was given a military funeral and buried at the cemetery in Kirchworbis on 11-04-1944. His grave was ordered leveled by the authorities of East Germany in 1988. Posthumously, Zwernemann had been promoted to Hauptmann, his rank age backdated to 01-04-1944
.