03/31/2011. The S.66 twin-hull flying boat, in essence, was an enlarged development of the S.55, with three separately-mounted engines and a greater carrying capacity, and is described in the October 13, 1932 issue of Flight, page 958 and page 959. Although built for commercial use the prototype (c/n 15001) flew for the first time in 1932 with the military serial MM229. Initially powered by 500 hp Fiat A.22R twelve-cylinder water-cooled V-engines, these were later replaced by similar 750 hp A.24R engines, which became the standard powerplant for production aircraft.
The prototype was followed by another twenty-three aircraft, the first of which became operational in late 1933, while the last was delivered in December 1937. The Italian airlines Aero Espresso Italiana, Societa Idrovolanti Alta Italia, Navigazione Aerea and Societa Aerea Mediterranea, all operated the S.66s. However, on October 28, 1934, Mussolini celebrated the anniversary of Rome's capitulation to Fascism by inaugurating the new combine of all the Italian airlines into one body called Ala Littoria (which meant, in a broad sense, 'Fascist Wings').
The pictured aircraft was registered I-NAVE on May 11, 1935, and started Ala Littoria operations from Malta on Saturday June 15, 1935, although for a very brief period, as only a week later, June 22, it crashed. While en route from Rome to Tripoli the aircraft was to make a scheduled stop at Malta. On the night approach, the aircraft encountered downdraft at a height of 50 ft (15 m) and crashed into the Marsaxlokk Seaplane Base, 4 mls (6.5 km) south-east of Malta's capital Valletta. All occupants were rescued, one of them seriously injured.
With thanks to Phillip Hayes, and Kenneth Cocks, chief librarian of "The Times of Malta", here is the article scanned from that news paper's June 26, 1935 issue.