Caproni Ca.4

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

Development

After designing the successful Caproni Ca.3 heavy bomber, Gianni Caproni of the Caproni 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, making a push-pull configuration. 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.

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. At least one variation of the center nacelle seated the crew in a two-seat tandem format with the forward position a gunner/pilot and the rear position the pilot. Others used a forward gunner with side by side pilot positions to the rear of the gunner. Two rear gunners were positioned one in each boom behind the center wing. An engineer or 2nd pilot could also be accommodated there.

Armament: 4 (but up to 8) machine guns 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. Photographs show at least four different arrangements with regard to the bombing nacelle.
* 1. No nacelle - presumably not a combat configuration.
* 2. A tall, narrow nacelle that housed approximately 12 internal bombs vertically and another 18 -20 strapped to the outside.
* 3. A shorter nacelle that may be the lower half of the tall nacelle but with no external bombs.
* 4. No nacelle but with a single long bomb/torpedo slung under the bottom wing.

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.

ervice 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 unstable and fragile appearance, the Ca.4 was well-designed. Its size, without regards to its height, was not any larger than that of other foreign heavy bombers. With Liberty engines, it had a fast speed, similar to other heavy bombers, while its bomb load had one of the largest capacities of that era. If it had been flown with other engines, its performance would have suffered.

Operators

* : Corpo Aeronautico Militare
*
*

pecifications (Ca.36)

aircraft specifications
plane or copter?= plane
jet or prop?= prop
ref=
crew= Four (pilot, co-pilot, front gunner, and rear gunner/mechanic)
capacity=
length main= 13.10 m
length alt= 42 ft 11 in
span main= 29.90 m
span alt= 98 ft 1 in
height main= 6.30 m
height alt= 20 ft 8 in
area main= 200 m²
area alt= 2,153 ft²
airfoil=
empty weight main= 6,709 kg
empty weight alt= 8,818 lb
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main= 7,500 kg
max takeoff weight alt= 16,534 lb
more general=
engine (prop)= Isotta Fraschini
type of prop=
number of props=3
power main= 201 kW
power alt=270 hp
power original=
max speed main= 140 km/h
max speed alt= 76 knots, 87 mph
cruise speed main=
cruise speed alt=
never exceed speed main=
never exceed speed alt=
stall speed main=
stall speed alt=
range main= 700 km
range alt= 378 nm, 438 mi
ceiling main= 3,000 m
ceiling alt= 9,845 ft
climb rate main= 125 m/min
climb rate alt= 410 ft/min
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
armament=
* 4 × 6.5 mm FIAT-Revelli machine guns, two in forward mounting and one in each of two rearward positions.
* 1,450 kg (3,913 lb) of bombs
avionics=

References

* [http://www.theaerodrome.com/aircraft/italy/caproni_ca4.html Caproni Ca.4]
* [http://www.aerei-italiani.net/Liste/aereicacciabombIgm.html AEREI ITALIANI] (Italian)
* [http://www.hq.nasa.gov/office/pao/History/SP-468/ch2-3.htm Quest for Performance: The Evolution of Modern Aircraft, Chapter 2: Design Exploration, 1914-18]

ee also

aircontent
related=

similar aircraft=

sequence=
Ca.1 -
Ca.2 -
Ca.3 -Ca.4 -
Ca.5

lists=
* List of military aircraft of Entente Powers in WWI
* List of bomber aircraft
see also=