KG 4 commanded by "Geschwaderkomodore" "Oberst" Martin Fiebig helped neutralise Dutch air power on 10 May 1940 by striking at airfields and Dutch AA positions and airlifted supplies to the "Fallschirmjäger" units in the Netherlands. Three Heinkels 111 leading an attack on Waalhaven-airport, Rotterdam in the early morning of May 10 belonged to "Stabsstaffel". Ca. 30 planes followed. After the German bombing, First Lieutenant P.Noomen of Dutch 3 JaVa took off as patrol commander in a Fokker G.I.A-311 armed with eight machineguns and managed to hit the leading, middle Heinkel 111 (5J+DA) flown by pilot Hlubeck and commanded by "Oberst" Fiebig. It tried to escape by flying lowly back northward over the Northsea. It was subsequently downed by famous Dutch pilot G. Sonderman flying his Fokker 311 after he had successfully hit and downed both a German Junkers Ju 52 and a Messerschmitt. After the quick surrender of the Dutch KG 4 shifted its attention to Belgium. During the Battle of France KG 4 helped paralyse Allied rail networks across Belgium. also flew sorties over Dunkirk. The II Gruppe also took part in the bombing of Rotterdam.