SILA originally ordered the Boeing 377 Stratocruiser to replace the unpressurized DC-4 on intercontinental routes, but delays at Boeing resulted in SAS ordering the Cloudmaster instead. One aircraft perished in 1948 in the Northwood mid-air collision. The aircraft remained the flagships of the fleet until 1952, when the intercontinental routes were taken over by the DC-6B. They were then used on European flights until being sold.