Air Zaïre the government. Part of the contract with Sabena saw the Belgian airline train Air Congo personnel for a six-year period, and by the end of 1962 Air Congo had 2,400 employees, of which some 1,100 were seconded from Sabena. By this time the airlines' destinations included Entebbe, Lagos, Nairobi, Ndola, Salisbury and Usumbura. Jet service to Brussels was inaugurated in March 1963 utilising a Boeing 707 which was leased from Sabena, and in April 1963 the airline joined the International Air Transport Association, becoming the 94th overall member. The airline signed an agreement with French airline Union des Transports Aériens
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.