SABCA S.11 SABCA S.11 The SABCA S.11 or SABCA S.XI was a prototype Belgian airliner of the 1930s. It was a three-engined high-winged monoplane intended for service in the Belgian Congo, but only a single example was built. In 1926, the Belgian government issued a specification for an all-metal trimotor airliner to replace the wooden Handley Page W.8 biplanes used by Belgian airline SABENA in the Belgian Congo. To meet this requirement, Sociétés Anonyme Belge de Constructions Aéronautiques (SABCA) offered a high-winged monoplane, the S.XI, designed by Henri Jullien, its chief engineer, which was intended to fly in 1928. The S.XI had
Airline teletype system although it is now owned by Rockwell Collins. In 1949, the Société Internationale de Télécommunication Aeronautique (SITA) was formed as a cooperative by 11 airlines: Air France, KLM, Sabena, Swissair, TWA, British European Airways, British Overseas Airways Corporation, British South American Airways, Swedish AB Aerotransport, Danish Det Danske Luftfartselskab A/S, and Norwegian Det Norske Luftfartselskap. Their aim was to enable airlines to be able to use the existing communications facilities in the most efficient manner. Morse code was the general means of relaying information between air communications stations prior to World War II. Generally, it was only necessary to relay