GOT: The Caproni Ca. 331
Posted 25 August 2008 - 03:38 PM
Caproni Ca.331 Raffica
The number of Italian aircraft, which are registered being the creation of eng. Cesare Pallavicino, project manager at Caproni's, is to be completed by the competition for a terrestrial reconnaissance aircraft in 1938, which was delegated to the firm C.A.B (Cantieri Aeronautici Bergamaschi). The main innovation was to form an entirely metallic construction. The plan foresaw a fuselage of metallic shell structure and the covering made of duraluminium, with an extended glazed nose occupying the bow of the aircraft. The low-fixed wing had an (inverted, RT) gull form, chest structure and was covered in duraluminium too.
The crew consisted of three persons: pilot, observer/gunner and wireless operator/gunner. Their positions were armoured. The armament based on a dorsal turret containing a Breda/SAFAT machine gun of caliber 12.7 mm, a ventral station carrying a same weapon and two more located in the wing roots. Last, there was an internal bomb bay able to contain a load of 1,000 kg, and four additional racks under the wings. For motorization, 2 Isotta-Fraschini Delta RC.40 engines of 770 hp each were chosen.
The aircraft became commissioned by the Regia Aeronautica in three prototypes (Ca.331A) on 15 October 1938 by contract No. 4136 for an amount of 3,932,512 Italian Lira, and were assigned the military matriculation 426, 427 and 428. The first copy had its maiden flight under the control of test pilot Ettore Wengi on 31 August 1940 from the airfield of Ponte San Pietro. The first results were better than expected.
In 1941, the military evaluations started at Guidonia under the command of Mario de Bernardi. In spite of the good test results, the direction of the Regia Aeronautica gave no resources to the type and handed it back to the firm. There it was examined by a German commission, which was favourably impressed by the performances and demanded a transfer to the German test center at Rechlin. Also here, the good performances did not result in an order for serial production, because of the use of precious light alloys caused big problems (see my remarks at the ending, RT).
When in 1942 the defensive situation got worse, Caproni received the demand for a modification of the aircraft into a nightfighter. The new version was called Ca.331B or Ca.331CN ("CN" = "caccia notturna", nightfighting, RT). The main difference was the change of the nose from glazed to solid, containing four guns, initially of same type. The engines were replaced by the more powerful Delta IV of 825 hp and equipped with new propellers. The second sample, MM.428, flew for the first time on 28 April 1941 under the control of Wengi from Ponte San Pietro (again see my remarks at the ending, RT).
Subsequently, both aircraft came back to the factory for to perform the necessary modifications. The successive tests on Furbara range showed positive results. The third sample, MM.426, was completed on 21 March 1941, but the wing realized in wood. The decision of its transformation to metal followed. In the light of the evolving situation the Regia decided the supply by 1,000 aircraft.
For what was found in the successive period, the reply of three store clerks claim an order stock of 100 samples by May 1942 (to C.A.B., Reggiane and Caproni Taliedo), but everything became cancelled in January 1943.
The manufacturer also produced motorization variants: first using Daimler-Benz DB 605 of 1,475 hp, then Isotta-Fraschini Zeta RC.42 of 1,250 hp, but the cancellation of orders stopped it all. In August 1945 (???, there surely was no post-war continuation of development, RT), the adoption of four Maser ("Mauser"?, RT) guns of caliber 20 mm in the snout was proposed, also an antitank-version carrying a cannon of caliber 37 mm.
To the date of the armistice, MM.427 and MM.428 were at Caproni Taliedo for completion and were dismantled by the Germans, while MM.426 was still in the phase of assemblage and did not carry out any flight. A realization characteristic of this aircraft is that the construction of different parts was performed in several firms of the Caproni group: front part by Caproni Taliedo, fuselage and engine nacelles by C.A.B, tail units by Caproni Trento and wing by Reggiane.
An optimal solution, had there been not too much time passing until to the final assemblage. Thus the life of an aircraft of interesting characteristics concludes, blocked by too long time needed for projecting and realization, a situation similar to other Italian planes.
Additional information by airwar.ru:
The aircraft is nicknamed "Raffica", what can mean "gust of wind" as well as "fire burst".
Germany considered an order for a certain G version - an assault trainer with double controls.
Using the FIAT RA-1050 RC.58 "Tifone" engines, the Italian copy of the Daimler-Benz DB 605, a maximum speed of 644 km/h was expected.
The dismantled aircraft were taken to Germany, where their trace is lost.
It is not the first time that I have some troubles with the texts of Sg. Dorati, often finding violations of the chronological and logical order within them. Above you see that the B version was ordered in 1942, but flew already in 1941. While German authorities ordered manufacturing of the aircraft in wood, MM.426 was discontinued because it already partly consisted of wood. Also, Sg. Dorati complains the long delays in development, but never gives a real explanation for that. Instead, he confuses reason and effect by remarking "blocked by too long time needed...". However, the underdog status of the Ca.331 is special even under Italian circumstances.
airwar.ru quotes a statement about the Ca.331 having "too many uncommon design characteristics". If so, what were they? Obviously to be seen there is only the use of inline engines, which were nearly discontinued in development in Italy. Concerning German demands about the material realization, further studies showed me that there never was any shortage of aluminium (remember the German production numers in 1944), so any consideration in this direction was wrong (although it was done during WWII, if you consider the transformation of the Ju 252 to the Ju 352).
Speculations about Caproni having political troubles in fascist Italy are allowed, but keep on being unfounded by sources. A general reason of the ineffectivity of Italian WWII warfare, including development of combat aircraft, might be seen in the unwillingness of levels below the highest command to truly cooperate with Germany, because a victory of the Axis powers would have brought Italy into a lasting dependence from the Nazi empire, not even for the fascists this being a very attractive expectation.
I also like to add some pictures, which are better than the ones you can find on the net because I improved them a bit using XnView. Sorrily, especially the first ones showed no improvement concerning the underwing structures.
#1-4: The first four ones are from the G.M.S. website and show the A version (MM.427):
Here in pic. #3 you can see the machine gun of the Caproni-Lanciani Delta turret pointing to the left side (from your position) and the balancing rod pointing to the right side:
#5 is from airwar.ru and shows the B version (MM.428), probably at shooting trials in Furbara. You see in wears three openings for gun muzzles on the left side, so contrary to the text the B version carried at least six frontal barrels, could have been eight if the wing root positions of the A version were not dropped:
#6 is from ww2aircraft.net, shows the B version (compare #3 showing the A version from a similar position) and gave me the only success in enlighting the underwing structure. I believe to see two bomb racks (the A version was told having four ones). I think, an armoured nose would make the B version a fine ground attacker too, especially regarding Italy having no own radar equipment for a nightfighter...
#7-8: I would like to add some model pictures too. #7 is from amv-liliput.org, #8 from modellingmadness.com. Sorrily the models of the B version don't repeat the attractive frontal window scheme the real B version had, see pic. #5. At least, the A version had a fine spotted camouflage scheme:
Hope you enjoyed, and best regards, RT
Posted 26 August 2008 - 02:31 PM
quote:Originally posted by Romantic Technofreak
... and the balancing rod pointing to the right side:
I always wondered what those were - thanks!
Posted 02 September 2008 - 05:31 PM
nice GOT as usual from you, and nice plane
I hope you do agree if I post a little bonus here: an image of the Lanciani turret with all the structure and mechanism unveiled
Posted 02 September 2008 - 06:40 PM
Good work, Romantic Technofreak.
Posted 02 September 2008 - 10:47 PM
Nice planes, nice photos.
And nice turret.
Posted 03 September 2008 - 12:42 AM
Nice post! We can talk about this one when you get here this coming weekend. As was mentioned, a nice art-deco style Italian classic. Might make a great turboprop! ... without the gunner, of course.
Hey Trexx! Wanna' get together with me and RT?
Let me know!
Posted 04 September 2008 - 12:13 PM
One of my fearless displays of ignorance: What is the long thin structure sticking up out of the turret? Not the gun - the other one.
Posted 04 September 2008 - 01:54 PM
Nick, what you see ist the balancing rod that always points in exactly the opposite ankle as the machine gun does. Thus gunners can turn the turret only by muscle power at any speed, as Italians were not willing or able to employ motors to drive turrets.
(I would have preferred a second machine gun instead, so I can fight two different targets at the same time...)
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