Sabena airliners which were augmented and later replaced by Douglas DC-6Bs. The DC-4s also restarted the airline's traditional route to the Belgian Congo. Sabena was the first airline to introduce transatlantic schedules from the north of England, when one of its DC-6Bs inaugurated the Brussels-Manchester-New York route on 28 October 1953. The Convair 240 was introduced in 1949 to partially replace the DC-3s that until then had flown most European services. As of 1956, improved Convair 440 "Metropolitan" twins began replacing the Convair 240 twins and were used successfully well into the 1960s between European regional destinations. In 1957, the long-range
Sun Country Airlines DC-10 in early 2001. In June 1999, the management of Sun Country launched a transformation from a charter carrier into a scheduled airline. New service from Minneapolis and Milwaukee began to destinations including Los Angeles, Seattle, Detroit, Washington, D.C. and Phoenix. The airline also started a frequent flyer program, Smile Awards. In 2001, Sun Country began to replace its entire fleet with Boeing 737 aircraft. As Sun Country reinvented itself, heavy competition from local incumbent carrier Northwest Airlines and the September 11 attacks caused a sharp decrease of traffic and revenue. The airline was losing large amounts of money by