Caproni Ca.111 - Design and Development

Design and Development

A robust and simple aircraft, it was meant to be used in harsh conditions with minimal support. It was designed by the engineer Rodolfo Verduzio of Gianni Caproni in 1931, and first flew in February 1932 as MM 205.

This aircraft was a high-wing monoplane, built with a robust but simple structure consisting of a tubular steel skeleton with a fabric and wood skin. Derived from the earlier Ca.101, it used a different engine. The fuselage was of square section, and the wing was practically rectangular, with the extremities sloped and the ailerons running the whole length of the trailing edge. Steel tubing was also used for the undercarriage. This was fixed and had a complex structure that had two legs supported by several steel tubes between the fuselage and the wings.

The crew consisted of three men. The pilot, a co-pilot/observer and a flight engineer/gunner.

The main innovation was the engine. While the previous Ca.101 had three units, the newer type had only one. This was a risk because the engines of the time were not very reliable. It seems that the gamble paid off as the Ca.111 was faster than the three-engine Ca.101 and even the Ca.133. The engine was a water-cooled Isotta Fraschini Asso 750RC 18-cylinder in a 'W' layout. The first examples were equipped with a four-blade wooden propeller. Later models were fitted with a three-blade metal propeller with variable pitch. The required pitch had to be set on the ground and was not variable in flight. It was heavier and more expensive but provided a worthwhile improvement.

Fuel capacity was 1,690 L (446 US gal) in two tanks, one of 1,060 L (280 US gal) and one of 440 L (116 US gal). Range was 2,000 km (1,240 mi). The oil tank was below the engine and contained 150 L (40 US gal).

Maximum payload was 2,000 kg (4,410 lb), but if necessary could be raised to 2,500-2,800 kg (5,510-6,170 lb).

The cockpit instruments were repeated for each pilot. The instrument fit included a 'Pezzoni' compass, a 'Sonia' aerometer, a variometer, 'OMI' altimeters and fire detectors with extinguisher controls. The canopy was detachable to allow for exit in an emergency. There was also a rice-transmitter radio, for the marconist-gunner. This consisted of a RE 350 and AR 5 transmitter-receiver. This allowed both telegraphic and voice transmissions. To make this possible, there were two radio antennas: one fixed, one flexible. There were two accumulators and two air-generators. Finally, there was a photographic, photoplanimetric O.M.I. 13x18 camera, or a OMI APR 3 panoramic. Sometimes, a cine-machine-gun was also fitted.

Defensive armament varied between three and six 7.7 mm (.303 in) machine guns. Initially, the armament was quite weak, one 7.7 mm (.303 in) Lewis Gun in the dorsal position, and one in each beam position. This was a serious failing as the gunner could only man one weapon at a time. One improvement was the replacement of the single dorsal gun by a turret fitted with two 7.7 mm (.303 in) Bredas. Another machine gun was sometimes fitted in the ventral position, both for offensive and defensive tasks. Some examples also had a machine gun fixed in the nose, firing with a synchronizer through the propeller disk.

Bombload, theoretically was up to 600 kg (1,320 lb), in practice, it was more. This load was held vertically inside the fuselage, and consisted of two launchers for:

• 6 × 100 kg/220 lb (total practical, 780 kg/1,720 lb)
• 6 × 50 kg/110 lb (total practical, 420 kg/930 lb)
• 6 × 24, 20, 15, 12, 10 kg (50, 40, 33, 26, 20 lb).

Up to 15 × 12 kg (26 lb), 15 kg (33 lb) or 24 kg (50 lb) bombs could be carried in a third launcher. It was also possible to carry two bombs of 250 kg (550 lb) or 500 kg (1,100 lb) or incendiaries (144 × 1 kg/2 lb and 144 × 2 kg/4 lb). Finally, chemical bombs could also be dropped.

The door for entry into the aircraft was on the left-hand side.

A civil version was built with seven seats. The Caproni Ca.140 was, instead, a retractable version of the basic project, but remained prototype. Another prototype was a version with a 3,000 km (1,860 mi) range, but the redesigned Ca.112 was not put into production. Its most notable difference was a new elliptic and enlarged wing.

One example had a 746 kW (1,000 hp) A.80 engine.

Possibly the most important version was the seaplane, fitted with two 'shoes' under the belly. It had been tested in 1932 and was called the Ca.111 Idro. The Idro version was the first to enter service. It was almost identical to the land version, but weighted 3,500 kg (7,720 lb) and had a 2,000 kg (4,410 lb) payload. The two shoes were made of cedarwood. The engine remained the same but with 1,940 L (510 US gal) of fuel. Range was greater, but speed was reduced. Defensive weapons were four 7.7 mm (.303 in) Lewis guns with 2,000 cartridges each. Bombload was similar to that shown above. An 800 kg (1,760 lb) torpedo could also be carried.