Mining ceased in Ny-Ålesund in 1929; it was taken up again in 1941, but because of the Second World War the town was evacuated the following year. From 1946, the Royal Norwegian Air Force started serving Ny-Ålesund with their Consolidated PBY Catalina amphibian aircraft. The aircraft were able to land if there was no ice on the fjord and lighting and weather permitted it. The first flight took place on 10 May and consisted of post drops. No further flights were carried out until 1949; one of the flights that year was an air ambulance operation. The service also dropped post at the other Norwegian settlements in Svalbard. In 1961, the Catalinas were replaced with Grumman HU-16B Albatross aircraft.