Air Zaïre airline was also operating Curtiss C-46s and DC-4s equipment, leased from Aerovias Panama Airways to complement the Sabena-leased aircraft. After the Republic of the Congo gained independence from Belgium in 1960, the Belgian national airline Sabena continued to operate routes in the country. Plans for the formation of a Congolese airline were delayed due to the Congo Crisis; however, in January 1961 a protocol was signed with Sabena for the creation of a limited liability company to be named "Air Congo". On the company was formed, and incorporated on 28 June with Sabena providing technical assistance and personnel. The Congolese
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