Fortress Den Helder
The Fortress Den Helder would see German air assaults from the first until the last hour of the May War, or rather even after the capitulation hour on May 14, when the city would erroneously be bombed by German bombers still. The reason for the contineous German attention was the large navy facility that the German kept in clear sight in expectance of British landings. Furthermore the airforce bases at Texel and south of Den Helder itself - 'De Kooy'- were of German interest too, as was the navy air service base at Texel. And obviously the contineous Dutch navy shipping going in and out of Den Helder and the approaches. It caused the Germans to be overhead regularly.
The Fokker D-XXI fighter squadron stationed at De Kooy had 12 planes available, of which eleven were ready to scramble. Two dozen navy training planes were parked around the field. The airbase had a defence of six light and four heavy machine-guns against airlandings. Three 2 cm light AA guns were the only nearby protection, but a battery of 7,5 cm AAA guns was located about 1 click north of the base.
The pilots were on alert when it was 03.30 hrs, engines warm. When the signal to scramble came all four patrols of three (one of two) planes took off shortly after each other. The patrols went in different directions. Some intercepted German fighters, others came into contact with He-111's that had previously attacked AFB Bergen near Alkmaar. A German Ju-88 was forced into an emergency landing at Noordwijkerhout. Other aerial combat ended without confirmed result. One D-XXI was shot down near Wassenaar, with the pilot killed. Soon D-XXI's returned for refueling and rearming and went up again, when suddenly a German squadron of Bf-109's appeared. Eight D-XXI's intercepted them. This time the Germans paid a heavy price. No less than four were shot down against zero Fokker's. The Bf-109's were fast, but in a tight dogfight the Fokker dominated.
A Fokker G-1 of the 3rd Squadron of Waalhaven landed on De Kooy and so did a Fokker T-V bomber. The latter would later be shot to pieces by a sudden German strafing of the base, that also saw most of the navy training planes go up in flames. Also D-XXI's were damaged during German strafing attacks, causing one more to go up in flames. Two became write-offs and were used for replacement parts. Another German strafing attack casued havoc again and costed yet another plane. In the end only one D-XXI had been shot down, but five more had gone lost on the ground. The balance of six planes was flown to the auxilary strip north of Amsterdam, called Buiksloot. It was an undetected field, from where the single engine fighters would continue to operate.
De Mok and the Vlijt
Also the navy air service base De Mok and airfield De Vlijt, both on the island Texel, were attacked by German fighter planes.
At De Mok a number of sea planes was shot into flames, others were sunk due to strained floaters. Some planes were evacuated.
At De Vlijt the personnel and AA had been on high alert since 0300 hrs too. Weapons were armed, but the airplanes were not operational and not prepared to scramble. Shortly after the invasion hours two low flying Bf-110's came flying from the southwest strafing with their guns and MG's, shooting the openly parked T-V to pieces. The heavy plane had not been suitable for parking outside the field for a more shielded position. The price for that was paid instantly. A scarce modern bomber was lost.
The Fokker G-1 and two D-XXI's, parked outside the airfield, as well as the seven D-XVII's, were all capable fighters, albeit that the latter were rather outdated. The airfield commander called the Air Defence staff to inform whether he was allowed to arm the ten fighters and use them for self-defence. He got word that this had to be decided and that he would be informed back. One of the enigma's of this short war was that the base commander never got the instruction to deliver the G-1 and D-XXI's to active fighter squadrons that would desperately need them. On the contrary, only the order would come to transfer the older seven D-XVII's to an active base! It shows how little control there was over the airforce in those days, that three modern capable fighters were entirely forgotten and wouldn't see an hour of air time.