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
Alcazar (airline) States started negotiating open skies agreements with the European Union (EU), which would allow any European airline to fly from any airport in their home country to any airport in the US, and similarly any US airline to fly from any US airport to any European airport. In the 1980s, SAS, Swissair, Austrian Airlines and Finnair had attempted to establish European Quality Alliance (EQA). In addition to codesharing and joint marketing, the alliance was largely based around technical issues and using the EQA brand as a "seal of quality". These had largely stranded because Finnair felt that SAS goal was