Flak corps A flak corps ( ) was a massed anti - aircraft ( AA ) artillery formation employed by the " Luftwaffe " for anti - aircraft , antitank , and fire support operations in World War II . A " Flakkorps " was a flexible organization that was made up of a varying number of AA regiments , brigades , or divisions . It was roughly equivalent in strength to a brigade or a division . A total of six flak corps were organized by Germany during the war . The flak corps , while mainly intended to support ground units with concentrated anti - aircraft fire , in many cases provided also antitank support . History . Flak corps did not exist before World War II . Until the end of war Germany eventually organized a total of six flak corps , being numbered I - VI , plus one short - lived special flak corps . Flak corps I and II were formed on 3 October 1939 . They grouped mobile AA battalions ( previously existing ) to overwhelmingly concentrate the firepower at points of decision on the battlefield . The original two flak corps were used in the Battle of France in 1940 , and later inactivated . They were reorganized for the German invasion of Russia and fought for the remainder of the war on the Eastern Front . The I Flak Corps was destroyed at Stalingrad and later formed again . The III Flak Corps was formed in February 1944 and fought on the Western Front . In total , III Flak Corps entered combat in Normandy with 27 heavy batteries , 26 light batteries and some 12 , 000 men . During the fighting in Normandy in 1944 , the III Flak Corps was motorized although not all authorized vehicles were present . It was eventually destroyed in the Ruhr Pocket in April 1945 . The IV Flak Corps was formed in July 1944 and supported Army Group G on the Western Front until it surrendered in May 1945 . The V Flak Corps was formed in November 1944 and fought in Hungary and Austria . The VI Flak Corps was formed in February 1945 and fought in northern Germany in support of the 1st Parachute Army . The flak corps " for special employment " ( " Flakkorps z . b . V . " ) was organized in 1945 to control V - weapons . Organization . Flak corps were large organizations of pre - existing AA units ( regiments , brigades , and divisions ) rather than being formed as new units from scratch . In 1943 Allied intelligence noted : " The Flak Corps is a wartime organization , and constitutes an operational reserve of the commander in chief of the German Air Force . It combines great mobility with heavy fire power . It can be employed in conjunction with spearheads composed of armored and motorized forces , and with nonmotorized troops in forcing river crossings and attacking fortified positions . It can also be deployed as highly mobile artillery to support tank attacks . " Flak corps did not include the majority of the Germany ' s flak force . Even considering only the " Luftwaffe ' s " flak units dedicated to direct support of " Wehrmacht " ground troops , most of them were not subordinated to flak corps . Flak corps were either partially motorized or fully motorized , depending on the degree of motorization of their subordinate units . The following orders of battle depict typical flak corps organizations in 1940 and 1944 : II Flak Corps , August 1 , 1940 : III Flak Corps , June 6 , 1944 : Assessment . Although the AA guns of all nations in World War II could be used against ground targets , Germany in particular used AA guns in multiple roles . The need for command and control of these assets led to the organization of larger units , culminating with the organization of flak corps . Although the Soviets also organized large air defense units , they were typically not used against ground targets . The flak corps above all provided additional antitank support for the German ground forces . In some cases , such as at Cagny in Normandy , these units achieved significant success against attacking Allied armored vehicles . The use of flak corps as ground warfare assets was complicated because they were part of the air force ( " Luftwaffe " ) chain of command even when supporting ground forces ( either " Heer " or " Waffen SS " ) . Given the expense of producing AA guns – in relation to the cost of antitank guns of the same capabilities – it is questionable if their use as antitank weapons was economical . As an organizational form , massed AA - gun formations represented a dead - end as large - caliber AA guns were phased out of military service in the 1950s and replaced by surface to air missile s .