SIAI-Marchetti S.55 flying-boat I-AABF (c/n 97), thought to be the S.55P prototype (with deeper hulls faired into the upper surface of the wing), joined the SAM fleet in June 1928. It was used predominantly on the Rome - Cagliari service, as marked on the forward section of the port hull in this rare flying shot of a SAM S.55R. This machine was withdrawn from use in 1933.

In 1925 Italian car and railway magnate Nicola Romeo acquired the licence to build the Fokker F. VIIB/3m trimotor; only three were built - I-AAXY, I-AAXZ and I-FERO - all of which served with ALI. The first two are seen here at a snowy Taliedo airport in Milan; I-AAXZ was lost when it crashed on Mt Basso, near Turin, in April 1936.

Designed by Rodolfo Verduzio, the Caproni Ca.133 was a development of the same company’s Ca.101 and was used extensively by Ala Littoria on its East African services. The airline’s services from the home country to its colonies and territories in the Horn of Africa were operated as part of the Linea dell’Impero, as the 1939 timetable, INSET, shows.

The Ca.133 was itself developed into the beefier 460 h.p. Piaggio Stella VII-engined Ca.148, which also incorporated a strengthened undercarriage and a deeper fuselage. Seven were operated by Avio Trasporti SA from Assab in Eritrea, including I-POGG (c/n 4145), seen here in pristine condition in Italy before its departure to Africa.

Designed as a successor to the SM.73, the SIAI-Marchetti SM.75 made its first flight in November 1937 and was the largest of the manufacturer’s trimotor transports. The type was the first of the company’s civil transports to be fitted with a retractable undercarriage and joined the ALSA fleet in 1938 to serve on long-distance routes.

The Caproni Ca.308 Borea (North Wind) was originally designed by Cesare Pallavicino, chief engineer at the Bergamaschi company, which was acquired by Caproni in the 1930s. The twin-engined wooden monoplane could carry three crew and up to seven passengers. This example, I-DRIA, joined the ALSA fleet in January 1936 and was one of five used along the North African coast by the airline. It was destroyed in March 1938.

Caproni Ca.101bis I-ABCB (c/n 3252) was one of six operated by Nord Africa Aviazione (NAA) along the North African coast between Benghazi and Tripoli in Libya. The tri motors entered service with the airline in mid-December 1931, but I-ABCB is listed as having been destroyed in March 1934. The Ca.101 bis was a slightly enlarged variant with more powerful engines for colonial service.

Aircrew and passengers pose for a photograph beside one of NAA’s six Ca.101s in North Africa. Only 18 civil Ca.101s were built.

Another type used exclusively by ALI, the Fiat G.18 was designed by Giuseppe Gabrielli and made its maiden flight in March 1935. After one prototype and two production examples, the type was modified with a revised fin and rudder and more powerful Fiat A.80 engines, to become the G.18V, of which a total of six was built.

The cabin of the Fiat G.18V accommodated up to 18 passengers in two single rows. In addition to the passengers, a standard crew for a G.18V was two pilots and a radio operator.

Essentially a civil version of the SIAI-Marchetti SM.79 three-engined bomber, the SM.83 was the smallest of the company’s trimotors and the prototype, I-LUCE, made its maiden flight in November 1938. This SM.83T (Terrestre), I-AZUR (c/n 34015), initially joined ALSA’s Atlantic Division, in whose colours it is seen here, but was transferred to the LATI fleet on the latter’s formation in September 1939.

Of similar configuration to the Junkers Ju 52/3m - but with the German utilitarian lines softened to provide a far more characteristically elegant Italian profile - the SIAI-Marchetti SM.73 trimotor first flew in 1934. Avio Linee Italiane’s six Alfa Romeo 126 RC.10-engined examples - I-SAMO, ’SETI, ’SUTO, 'SAUL, ’SITA and 'STAR - joined the ALI fleet in early 1937.

During 1934-35 SIAI-Marchetti built three SM.74 four-engined 24-passenger landplanes for Ala Littoria - I-URBE (as seen here), I-ALPE and I-ROMA. The first two were powered by four 700 h.p. Piaggio Stella X.RC radial engines, while l-ROMA was fitted with Alfa Romeo Pegasus IIIs. All three later served with the Regia Aeronautica.

The CANT Z.506 seaplane, designed by Filippo Zappata, became a stalwart of the Ala Littoria fleet, the first production batch, powered by Wright Cyclone engines, joining the fleet in 1936. This Z.506C, I-DUNA, fitted with Alfa Romeo engines, joined the fleet in September 1938 and was impressed into military service in June 1940.

The cabin of the CANT Z.506C was divided into two sections, each containing six seats (although up to 15 or 16 in total were sometimes fitted). The forward section was immediately aft of the cockpit and radio operator’s station, as seen here. Note the rather elegant oxygen hoses attached to the cabin wall, for use on services over high terrain.

Designed by Celestino Rosatelli specifically for ALI’s Venice-Milan-Paris service, the sole Fiat APR.2, I-VEGA, first flew in 1935 and began plying its trade on the route the following year. Accommodating two pilots and 12 passengers, the APR.2 was reported to be the world’s fastest airliner in regular service on its introduction.

Designed by Mario Castoldi, the Macchi MC.100 trimotor twin-finned flying-boat was a development of the twin-engined single-finned MC.94, and joined the ALSA fleet in the spring of 1939. The three examples built - I-PACE, l-PLIO (seen here) and I-PLUS - all served with Ala Littoria, often on services to Spain and Portugal.

SIAI-Marchetti SM.71 I-EOLO was one of at least five absorbed into the Ala Littoria fleet from SAM, and served with ALSA until October 1939, when it was destroyed. The trimotor, which first flew in late 1930, was the first of SIAI-Marchetti’s multi-engined landplanes and could accommodate three crew and up to ten passengers.

SIAI-Marchetti S.59P I-AACO (c/n 9566) joined the SAM fleet from AEI in late 1934.

The sole SIAI-Marchetti S.84 at Zurich.