At dawn on 9 April 1940, the Norwegian Jagevingen at Fornebu, Oslo, had seven of the ten available Gladiators serviceable, while the unit had ten officers and sergeants available to fly them, three of them under training. The serviceable Gladiators were 413, 419, 421, 425, 427, 429 and 433.

Just before 0600 on 9 April 1940 Lieutenant Dag Krohn (Gladiator 421), Sergeant Kristian Fredrik Schye (427) and Sergeant Per Waaler (429) were sent off on patrol, but found nothing and returned about 50 minutes later.
At 0700 they got reports of large formations of enemy aircraft were approaching and he scrambled together with four other Gladiators. He attacked an estimated 150 aircraft of several types - identified as He111s, Do17s, Bf110s and Ju52s. He claimed a Heinkel shot down south-west of Fornebu, and then a ‘Do17’, which went down steeply over Nesodden after he had obtained hits on the cockpit area. Two Bf110s then attacked him, but he escaped these in clouds, subsequently attacking another ‘bomber’ and believing that he had put the rear gunner out of action. Returning to Fornebu, he strafed some Ju52/3ms on the ground here, landed on the north-eastern bay of Tyrisfjord, where he found Rolf Tradin and his Gladiator.
In 1978 members of the Norwegian Aviation Historical Society dug up the remains of the aircraft that Krohn had shot down at Nesodden, establishing beyond doubt that it had been a Bf110; the crew had been killed. There is little doubt that this was the Bf110 of 1./ZG 76 flown by Leutnant Erhard Kort and with air gunner Unteroffizier Heinrich Bockheimer.

The Gladiators of Lieutenant Krohn (in 421) and Lieutenant Tradin (in 429) taxiing on Tyrisfjord on 9 April 1940.

Later in the morning Lieutenant Krohn and Lieutenant Tradin took of from Tyrisfjord and flew to Hamar, landing here on Lake Mjösa. Unfortunately the wheels of Tradin’s aircraft went through the ice, and like the one flown by Braathen at Lake Bogstad, it was trapped immovably. It had to be abandoned, and was later captured by the Germans. In the afternoon Krohn took off again alone, flying to Brumunddal, where the remains of the Bomber Wing had arrived from Sola. Here however he was ordered to drain the oil from his aircraft as this was needed for the surviving Caproni, and the Gladiator had to be left behind. It was collected later in the month and flown to Vangsmjösa to join what had become Group ‘R’; it was the sole surviving Norwegian fighter.

Lieutenant Krohn (to the right) photographed at Hamar on 9 April 1940. This was at the time the only operational Norwegian Gladiator left.

Krohn survived the war with 2 victories, both of them claimed while flying the Gloster Gladiator.

Claims:

Kill no.	Date	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1940
1	09/04/40	1	He111 (a)	Destroyed	Gladiator	421	SW Oslo/Fornebu	Jagevingen
2	09/04/40	1	Do17 (b)	Destroyed	Gladiator	421	Nesodden	Jagevingen
	09/04/40	1	enemy bomber	Damaged	Gladiator	421		Jagevingen

Biplane victories: 2 destroyed, 1 damaged.
TOTAL: 2 destroyed, 1 damaged.
(a) Not confirmed with German sources.
(b) Bf110C 'M8+?H' of 1./ZG76 flown by Leutnant Erhard Kort and with air gunner Unteroffizier Heinrich Bockheimer, both killed. Perhaps shared with Sergeant Waaler. Totally Norwegian units claimed 19 aircraft during the day of which fighters (the rest was claimed by ground gunners) claimed six. Luftwaffe lost two Bf110s and a Ju52/3m in combat, six Ju52/3ms, one Bf110 and one He111 being brought down by ground fire.

Sources:
Fledgling Eagles - Christopher Shores with John Foreman, Christian-Jaques Ehrengardt, Heinrich Weiss and Bjørn Olsen, 1991 Grub Street, London, ISBN 0-948817-42-9
Gloster Gladiator - Alex Crawford, 2002 Mushroom Model Publications, Redbourn, ISBN 83-916327-0-9
Gloster Gladiator Home Page - Alexander Crawford.