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 Flight 503 communication was cut off. The aircraft had crashed somewhere in the mountains of Rieti, Italy North-East of Rome and was now missing. Sabena itself got notified about the missing aircraft that same night at 23:15 but would not make an official statement until the morning of the following day. The airplane had crashed somewhere in the mountains of Rieti, Italy North East of Rome which were known for being difficult to access and also lay in a nature reserve where wolves roamed. The Italians immediately started a search and rescue mission to locate the missing aircraft and rescue its occupants.