The 333 Sqn had continued to operate the Catalinas through the 1950s, although they by the end of the decade were all but modern. The Norwegian authorities agreed to receive eighteen Grumman HU-16B-ASW Albatrosses through the Marshall Plan. These flying boats were intended for maritime surveillance and transport to Svalbard, as well as submarine sweeping. 330 and 333 Sqn would receive nine airframes each. Combined they would provide 8,100 flight-hours annual, up from 2,400 with the Catalinas. Training was carried out by the United States Coast Guard and Air Force.