on 9 April 1940, German Luftwaffe-aircraft landed at Fornebu. There was no attempt by the civilian airport authorities to hinder this, such as driving cars onto the runway, although several German aircraft collided with each other during the landing. A KLM aircraft had a scheduled service that morning, and the captain was ordered to leave the passengers, take the crew and return to Oslo. On 12 April, the airport was bombed by the British Royal Air Force. On 14 April, the KLM captain was granted permission to fly back to Amsterdam with the crew, albeit without any passengers. The German military used Fornebu heavily during the war, but it was never of any strategic importance, since it was located far from any battle zones. During the war, the airport officially remained owned by the municipality. By orders of the German authorities, the main north–south runway was expanded to , and all facilities not yet built were completed. However, during the war all other runways than the main north–south were taken out of use. At the north end of the runway, the Luftwaffe built several hangars and a prison camp. Prisoners were used to keep the runways free of snow during winter, by marching along them and stomping the snow down. In May 1945, as German forces were ousted from Norway, the airport was taken over by the Allies and the Royal Norwegian Air Force. None of the civilian airlines were in operation, and the Air Force started flying commercial flights. In addition to previous lines, a route was started to Northern Norway, although it had to be terminated for the winter. Due to the lack of qualified personnel, the international services had to be terminated as well. In early 1946, management of the airport was transferred back to the municipality. Due to the technological development of aviation during the war, the runway needed to be expanded. The runway was sufficient for Douglas DC-3 aircraft, but insufficient for larger Douglas DC-4s. The latter were all used by American Overseas Airways, DNL on its North America routes and British European Airways on its route to London, which were all transferred to Oslo Airport, Gardermoen. Expansion On 1 November 1947, Norsk Spisevognselskap established a restaurant at the airport. In 1946, DNL launched plans to expand the north–south runway to by taking into use the whole peninsula. In addition, it wanted a second east–west