The Caproni Ca.4 was an Italian heavy bomber of the World War I era.

Contents

1 Development 2 Variants 3 Service history 4 Technical description 5 References 6 Specifications (Caproni Ca.42) 6.1 General characteristics 6.2 Performance 6.3 Armament 7 Related content

Development

After designing the successful Caproni Ca.3 heavy bomber, Gianni Caproni of theCaproni works designed a much bigger aircraft. It shared the unusual layout of the Caproni Ca.3, being a twin-boom aircraft with one pusher engine at the rear of a central nacelle and two tractor engines in front of twin booms. The most distinguishing feature of the new plane was, that it was built in a rare triplane layout, instead of the more common biplane.

The huge new bomber was accepted the Italian Army under a military designation Ca.4, but it was produced in several variants, differing in factory designations.

Variants

Note: during the war, all these aircraft were designated Ca.4 by the Italian Army. At the time, Caproni referred to the various designs by the total power of their engines. After the war, Caproni devised a new designation scheme for their own design - these are used below.

• Ca.40 - single prototype
• Ca.41 - production variant, essentially similar to the prototype and powered by 3 Fiat A.12 inline engines of 281 kW (210 hp). A few Ca.41s were powered by 186 kW (250 hp) Isotta-Fraschini engines instead. These were referred to internally by Caproni as the Caproni 750 hp. 41 built
• Ca.42 - powered by Liberty 298 kW (400 hp) inline engines and known internally as the Caproni 1,200 hp. 12 built
• Ca.43 - single example of a floatplane variant.
• Ca.48 - airliners converted from Ca.42s after the war. Capacity of 23 passengers
• Ca.51 - single example of a considerably enlarged design with biplane tail and tail barbette. 3x 522 kW (700 hp) Fiat A.14 engines
• Ca.52 - Ca.42s built for the RNAS. 6 built
• Ca.58 - Ca.48s re-engined with Fiat A.14 or Isotta-Fraschini V.6
• Ca.59 - as for the Ca.58, but this designation used for customers outside Italy.

Production figures differ in publications. The most likely number is 38 of all Ca.4 variants (other quoted figures are: 38 of Ca.40 and Ca.41 and 6 Ca.42 or 32 Ca.42 and 21 of other variants). Numerous publications incorrectly refer to all variants as the Ca.42.

Service history

Ca.4s were tested by the Italian Air Force in 1917 and began operations in 1918. They were used for attacking targets in Austro-Hungary. In April 1918, 6 Ca.42s were used by the British RNAS (No. 227 Sqn ). At least three CA.42s were sent to the USA for evaluation. After the war, the Ca. 4 was replaced in Italy by the Ca.36.

Despite its fragile looks, the Ca.4 was quite a good design. Its size, except for height, was not bigger than that of foreign heavy bombers. With Liberty engines, it had a good speed, comparable with other heavy bombers, while its bomb load was one of the biggest in that period. With other engines its performance was not so good.

Technical description

Three-engine, twin-boom triplane of a wooden construction, covered with fabric. The open center nacelle was attached to the undersurface of the center wing. It contained the pusher engine, pilot, and forward gunner. Two rear gunners were positioned in each boom behind the center wing. An engineer or 2nd pilot could also be accommodated there.

Armament: 4 (but up to 8) machineguns Revelli 6.5 mm or 7.7 mm in front ring mounting and two boom ring mountings. Bombs were suspended in a bomb bay, which was a long and narrow container fixed to a lower wing.

References

• Caproni Ca.4
• AEREI ITALIANI (Italian)
• Quest for Performance: The Evolution of Modern Aircraft, Chapter 2: Design Exploration, 1914-18

Specifications (Caproni Ca.42)

General characteristics

• Crew: five
• Length: 13.10 m (42 ft 11 in)
• Wingspan: 29.90 m (98 ft 1 in)
• Height: 6.30 m (20 ft 8 in)
• Wing area: 200 m² (2,153 ft²)
• Empty: 4,000 kg (8,818 lb)
• Loaded: kg ( lb)
• Maximum takeoff: 7,500 kg (16,534 lb)
• Powerplant: 3x Liberty engines , 298 kW (400 hp) each

Performance

• Maximum speed: 140 km/h (87 mph)
• Range: 700 km (438 miles)
• Service ceiling: 3,000 m (9,845 ft)
• Rate of climb: 125 m/min (410 ft/min)
• Wing loading: kg/m² ( lb/ft²)
• Power/Mass: kW/kg ( hp/lb)

Armament

• 4x 6.5 mm Revelli machine guns , 2 in forward mounting and 1 in each of 2 rearward positions.
• 1,775 kg (3,913 lb) of bombs

Related content

Related development:

Comparable aircraft:

Designation sequence: Ca.1 - Ca.2 - Ca.3 - Ca.4 - Ca.5