Sabena from Seaboard World Airlines, using them mainly on transatlantic routes. In the same period, there were experiments with helicopter passenger service using Sikorsky S-58 aircraft from Brussels to Antwerp, Rotterdam, Eindhoven and the Paris heliport at Issy-les-Moulineaux. 1960 saw the introduction of the Boeing 707-320 intercontinental jet for trans-Atlantic flights to New York. SABENA was mainland Europe's first airline to operate a jet across the Atlantic (BOAC had been flying jet transatlantic services using the de Havilland Comet 4 since 4 October 1958). One of Sabena's aircraft became the first Boeing 707 to crash while in commercial service when Flight
Boeing 707 the McDonnell Douglas MD-95 to Boeing 717 after the company was merged with Boeing. Boeing's customer codes used to identify specific options and livery specified by customers was started with the 707, and has been maintained through all Boeing's models. In essence the same system as used on the earlier Boeing 377, the code consisted of two digits affixed to the model number to identify the specific aircraft version. For example, Pan American World Airways was assigned code "21". Thus, a 707-320B sold to Pan Am had the model number 707-321B. The number remained constant as further aircraft were purchased;