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 720 producing each. At one point in the development phase, it was known as the 707-020, then 717-020, although this was the Boeing model designation of the KC-135 and remained unused for a commercial airliner until it was applied to the MD-95 following Boeing's merger with McDonnell Douglas in 1997. Because the aircraft systems were similar to the Boeing 707, no prototype Boeing 720 was built; any different systems were tested on the Boeing 367-80. The first 720 took its maiden flight on November 23, 1959. The type certificate for the 720 was issued on June 30, 1960. It was first