CANT 18 (1926)

29 built 1927-28

Development

In 1926, SISA asked the Cosulich group to build an acrobatic seaplane for advanced training to be assigned to new pilots of the Portorose Flight School. The result was a wooden hulled seaplane, sesquiplane with top wing suspended engine, tow bladed wooden propeller and a structural safety coefficient of 12, allowing the most extreme acrobatic maneuvers without limitations. The tCANT 18 was designed by Chief Engineer Raffaele Conflenti and built by the Cantiere Navale Triestino (CANT). It was essentially a development of the previous CANT 7, and had to have a trainer available for the new generation of pilots deployed on newly created commercial routes owned by the Cosulich Brothers of Trieste, the same ones who had founded CANT.

Design

The CANT 18 was in straight line designed along the same line of previous models going back to Macchi, themselves based on Austro-Hungarian models such as the Lohner L. There was an all-wooden bult hull, carefully shaped and very aerodynamic, as well as quite rigid, fitted with internal bulkheads to provide buoyancy in case the hull was punctured. The fuselage provided the main floatation, with two smaller floats under the lower wings. The upper wing supported by reinfirced struts in N style arrangement rested on top of the main pushed engine. The wooden two-blased propeller was indeed at the rear, far from the pilot. The CANT 18 was unarmed and if some were two-seaters, used for training, the bulk were one-seaters, so there was no machine gun nor bombs carried. The model was mostly used in WW2 for training and liaison.

Compared to its predecessor, improvements were made both to the overall aerodynamics and hydrodynamics with a reworked central hull. While maintaining a similar appearance to the previous CANT 7, the CANT 18 had the structure of its wings modified and reinforced. The conventional structure was replaced by a more advanced Warren truss system, characterized by tense and compressed diagonal beams and the absence of struts. Thus, causing less drag and increasing performances. The CANT 18 was still a demanding machine, requiring particular care for pilots but it was able to give great satisfaction to experts due to its qualitied. Extremely robust, the CANT 18 could have been used as a fighter or even dive bomber to some extent.

The CANT 18 came out in three variants with gradual improvements in engines and performances. The first serie had the sotta Fraschini V6 260cv while the bis had the Asso 200 rated for 250cv and one and onl ter used the army choice Fiat A20 da 410 hp. The latter had even greater performances but the weight of the engine and limits of the structure made it unsuitable as a fighter. The first serie was 960 kgs empty, the Bis was 975 kg. and the ter weighted 1050 kg. Loaded figures, max take off weight are unknown. The first serie was capable of 180 km/h and the CANT 18 bis of 190 km/h (bis), the Ter was capable of 230 km7h but in 1929 it was seen as unsufficient. Ceiling was 5500 for the first serie and bis, and 5800 meters for the CANT 18 ter. Autonomy and range were of 600 km for the CANT 18 bis and 800 km for the CANT 18 ter.

Versions

CANT 18: single-seater, 250 HP (187 kW) Isotta Fraschini V.6 engine, 17 made
CANT 18bis: 2-seater with a 260 HP (191 kW) Isotta Fraschini Asso 200, 10 made
CANT 18ter: Military version with a 410 HP (302 kW) Fiat A.20 engine, one tested.

Production and Planned replacement:

Most of the aircraft produced were used by S.I.S.A. owned by the Cosulich Brothers. In all, there were 17 made of the 1st serie, ten of the CANT 18 bis and two CANT 18 ter. The CANT 18 proved to be robust and reliable, remaining in service from 1926 to 1944. In all, 25 were used for civilian service: the I-OCIA I-OCIB I-OCIC I-AZAS I-AZAD I-OCIE I-AZAN I-AZAI I-AZAO I-AZAU I-AZAX I-AAKE I-AAKA I-AAKB I-AAKC I-AAKD I-AAKF I-AAKG I-AAKH I-AAKY I-AAKI I-AAKX I-AAKJ I-AAKX I-AAKW. In 1940 the ones still in service were used to train pilots and for liaison. Overall, the Italian Air Services Company (S.I.S.A.) operated with 25 CANT 18 and 18bis models.

The Regia aeronautica operated 12 of them, of the two types and the single CANT 18ter until 1944 for liaison and reconnaissance.
The third operator was the Uruguay Navy (Servicio Aéronautico de la Marina Uruguaya) which operated two CANT 18bis, delivered in September 1929, operated from the Isla de la Libertad seaplane base. They were still listed as active in WW2.

Originally, two were ordered for tests by the Regia Aeronautica. The first was the only CANT. 18ter (1927) planned as a seaplane fighter but not adopted. It was assigned to the High Speed Flight Department of Desenzano. The second one was a modified CANT. 18bis ordered in 1929 and, after evaluation tests, it was reassigned to SISA so in civilian service. In 1933, the Portorose School was transferred to the military authorites which also gained its 11 CANT 18, which were all passed on to the Regia Aeronautica. The last was retired in 1944. In 1934 another CANT 18bis was donated to the “Ernesto Gramaticopulo” Aeroclub of Trieste.

⚙ specifications
Empty Weight	975 kg (2,150 lb)
Lenght	8.68 m (28 ft 6 in)
Wingspan	10.50 m (34 ft 5 in)
Engine	Isotta Fraschini V6 water-cooled in-line 187 kW (250 hp)
Top Speed	190 km/h (120 mph, 100 kn)
Range	600 km (374 mi, 325 nmi)
Ceiling	5,500 m (18,040 ft)
Armament	None
Crew	2, pilot and instructor