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, 423, 425, 427, 429 and 433.

Just before 06:00 on 9 April 1940, Lieutenant Dag Krohn (423), 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 (in 429) together with four other Gladiators. He attacked an aircraft, which he identified as a Heinkel, which started to go down before he lost sight of it. This claim is not confirmed with German sources although Captain Erling Munthe Dahl, wing commander of Jagevingen, saw this machine spin and crash near the airfield. Perhaps it was the Bf 110. Maybe this was the Bf 110 of 1./ZG76 flown by Leutnant Erhard Kort, who was shot down and killed together with his air gunner Unteroffizier Heinrich Bockheimer by Krohn (which identified it as a ‘Do 17’).
Waaler was then attacked by Bf 110s. In the thick of a dogfight, he ran out of ammunition and turned for base. His engine began to give problems however and started to cut as he went in to land. His Gladiator had probably been hit by Unteroffizier Mütschele, which claimed a Gladiator at 08.38 On the field he found Sergeant Lütken’s aircraft. Re-arming of Waaler’s aircraft began at once, but at this point the Bf 110s of 1./ZG 76 came in to strafe, and he was forced to leap from the cockpit and into a trench. Looking out, he saw both Gladiators in flames. The two Gladiators were destroyed by Oberleutnant Werner Hansen, which led eight Bf 110s of 1./ZG76 in the attack on the airfield.

Per Waaler escaped to the U.K.

In 1941, he served as an instructor in Canada.

In 1943, he was assigned to the Bomber Command.

On night of 23/24 May 1943, he flew his first (of a planned two) missions as co-pilot on a Halifax out in the attck on Dortmund. Near the city they were attacked by a Ju 88 night-fighter. In the first attack it damaged and started a fire in the outer starboard engine. They managed to get that fire under control but the Ju 88 attacked a second time and the Halifax caught fire. The crew baled out but four men were killed while four of them survived. Waaler managed to stay on the run for five days before he was captured and emprisoned in Stalag Luft III for the remainder of the war.

Waaler ended the war with one biplane victory, this one being claimed while flying the Gloster Gladiator.

After the war, Waaler returned to Oslo with his Canadian wife Ruth.

Per Waaler lived in Oslo and passed away in 2014.

Claims:

Kill no.	Date	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1940
1	09/04/40	1	He 111 (a)	Destroyed	Gladiator	425	Oslo/Fornebu	Jagevingen

Biplane victories: 1 destroyed.
TOTAL: 1 destroyed.
(a) Not confirmed with German sources but confirmed by his wing commander. Perhaps shared with Lieutenant Krohn. Totally Norwegian units claimed 19 aircraft during the day of which fighters (the rest was claimed by ground gunners) claimed six. Luftwaffe lost two Bf 110s and a Ju 52/3m in combat, six Ju 52/3ms, one Bf 110 and one He 111 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.
Additional information kindly provided by Tor Idar Larsen.