APOD
The Italian Aviation Industry Paper 2 Part Bombers
Breda Ba.65 bis
The Ba.65 sprang from the concept popular in the 1930s, the ‘battleplane’. Such a machine would be jack-of-all-trades. This was what Colonel Amadeo Mecozzi sought as modern ground-attack plane for the RAI. Mecozzi wanted a fighter, light bomber, army cooperation and photo- reconnaissance amchine. The design of the Societa Italiana Ernesto Breda, was selected.
Ba.64. Developed in 1932 from the Ba.27 single-seat fighter, the Ba.64 was completed early in 1933 as a cantilever monoplane with a Bristol Pegasus radial engine license-built by Alfa Romeo, in a long-chord cowling. This was later replaced by a 650 hp Alfa Romeo 125 RC35. Armament was four 7.7mm Breda-SAFAT wing guns and 880lb of bombs in racks under the wings. The basic problem with the Ba.64 was its large size and slow speed (220mph) which made it useless for recce or fighter duties and marginal for ground attack. .Production Ba.64s were delivered in mid 1936 and were a profound disappointment: the type was a failure. Few were built.
Ba.65. Evolved from the Ba.64, the Ba.65 was intended as an interceptor and attack-reconnaissance plane with two 12.7mm and two 7.7mm Breda-SAFAT machine guns, internal stowage for a 440lb bomb-load and external racks able to take another 2,200lb. The prototype flew in Sep 35 using a Fiat A80 RC41 18-cylinder, twin-row radial engine with a takeoff rating of 1,000 hp. Production began in 1936, the initial model having a Gnôme-Rhône 14K 14-cylinder radial of 900 hp. The single-seat Gnôme- Rhône version of the Ba.65, of which 81 were built, attained a maximum speed of 258 mph at 16,400 feet and 217 mph at sea level. Maximum cruising speed was 223 mph at 13,125 feet, and range was 466 miles with a 440-pound bomb load. The service ceiling was 25,590 feet. The type saw service in the Spanish Civil War.
Ba.65 bis. While the Ba.65 was in Spain, the two seat Ba-65bis was developed. When Italy entered World War II the RAI had 154 Breda Ba.65s in its inventory, including 119 fitted with Fiat A80 RC41 engines and a small number of Ba.65bis two-seaters with a manually operated 12.7mm machine gun in the rear gunner's pit rather than the Breda L turret. Owing to the unsatisfactory performance of the Fiat A80 RC41 under desert conditions, all Ba.65s with that power plant were re-engined with the Isotta-Fraschini-built Gnôme- Rhône 14K before being committed to North Africa. In 9/39, Ba.65s equipped the 101st and 102nd Squadrons of the 19th Group of the 5th Stormo, the 159th and 160th Squadrons of the 12th Group, and 167th and 168th Squadrons of the 16th Group, both components of the 50th Stormo. Soon after Italy entered the war on 6/10/40, however, it became clear that the large single-engine attack bomber was as vulnerable to enemy fighters as was the contemporary Fairey Battle.
War Experience. By mid- 1940, the only Ba.65s in a position to see any combat were those of the 50th Stormo in North Africa (159th Squadron and the 160th Squadron), and they contributed little. Attrition, a shortage of spare parts and a realization by the Italian army that the Ba.65s were not really an effective weapon resulted in the replacement of the Ba.65 in the 160th Squadron with the Fiat C.R.32 quater, a close-support fighter-bomber adaptation of the 1932-vintage C.R.32 biplane fighter.
In September, the 168th Squadron, equipped with 14K-powered Bredas, commenced operations alongside the beleaguered 159th. In December the British went over to the offensive, and the Ba.65s, joined by a few reinforcements from Italy, fought valiantly but vainly to stem the onslaught. At the end of December, the 168th Squadron, its aircraft decimated by foul weather conditions as well as combat losses, was disbanded. At the end of 1/41, the advancing British found six dilapidated Ba.65s lying abandoned at Benghazi airfield. The surviving aircrews of the 159th Squadron were transferred either to fighter squadrons or to dive-bombing units equipped with the Junkers Ju-87B Stuka.
APOD. In APOD, the ~120 surviving Ba.65 and Ba.65bis are progressively withdrawn and stored at the end of 1940 except for those in Africa. The basic problem with this now-elderly machine are the usual ones. It is seriously underpowered and it is conceptually obsolete. However, the RAI is perennially short of aircraft.
Ba.65C. In 1941, as Stella Dorata production ramps up, the type is reworked by Breda as a short-range night bomber. The 900hp Isotta-Fraschini K.14 is replaced with a more reliable 1300hp engine, the wing guns are removed and the type redesignated Ba.65C; a night bomber. All the conversions are completed by December 1941 and the type sees extensive service against Malta and later against Allied targets in Sicily. It is a modest success in this relatively undemanding role. By 1944 the survivors have been withdrawn to training and anti-partisan duties.
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Caproni CA.135
In 1934 Cesare Pallavicino arrived at Caproni (as chief designer) from Breda, and the RAI issued a requirement for an advanced twin-engine medium bomber.
it called for a maximum speed of 240 mph at optimum altitude, the ability to carry a bomb load of 2,646 pounds over a range of 621 miles and the ability to maintain an altitude of 16,450 ft on the power of one engine. Pallavicino’s design was a cantilever monoplane of mixed construction. The fuselage had a forward section of light alloy semi- monocoque construction and a rear fuselage section of welded steel tube with fabric covering. The wings were of mixed metal and wood construction. Defensive armament was provided in the form of three Breda turrets: with either a single 12.7mm MG or two 7.7mm.
The prototype flew April 1935 with two 800 hp Isotta-Fraschini Asso XI RC Vee engines. The Italian air force felt it had potential and in 1936 ordered 14 examples of the Ca.135 Tipo Spagna (Spanish model). None of the aircraft served in Spain. It was then re-designated as the Ca.135/Asso for its engines. Its weight had increased a lowering of the maximum speed to 249 mph and the cruising speed to 227 mph at optimum altitude. The climb rate and service ceiling were lowered while range was increased.
The RAI felt the Ca.135 was underpowered. Early in 1938 the Ca.135 Tipo Spagna airframes were revised for trials with a pair of 1,000 hp engines, either Fiat A.80 RC.41s or Piaggio P.XI.RC.40 radials. Trials revealed that the Fiat engines were unreliable and failed to improve performance as significantly as the Piaggio engines.
The Piaggio engine aircraft proved successful, especially after they had been revised with a cleaner nose. The original Breda dorsal turret was replaced with a more modern Caproni-Lanciani turret. Despite its improved performance, the Ca.135/P.XI was not ordered by the RAI, which preferred tri-motor bombers. The Imperial Japanese army air force evaluated the type in competition to the Fiat BR.20 and preferred the latter.
Thus production of the Ca.135/P.XI was undertaken for a sole export customer, which was the Hungarian air force that received 100 of the type in 1939 and 1940. These aircraft operated with some success against the Soviets in 1942 once Hungary joined operations on the Eastern Front.
The last development of the series was the Ca.135bis/Alfa that was fitted with a dihedral tailplane and two 1,400 hp Alfa Romeo 135 RC.32 Tornado radial engines. This prototype had a maximum speed of 301 mph, but it was clear by this time that the development potential left in the Ca.135 was marginal and no production was authorised. This left Caproni with a production gap, which was filled with the new dive bomber.
Cant Z.1007 Alcione Series
The Cant Z.1007, SM.79 and BR.20, constituted the Regia Aeronautica's standard equipment in 1940. A total of 1,560 aircraft were built in four production series from 1939 to 1945. The Alcione was widely used on all fronts, proving to be an effective aircraft, despite the emergence of problems of structural weakness in extreme climates, such as Russia, due to its being built entirely of wood. This feature kept it in production in 1944/45.
The project was launched in 1935 with the first prototype flying on 3 Nov 37. The test flights were disappointing as the machine was underpowered. Modifications were carried out but lack of engine plagued the aircraft built from 2/39-10/39. The problem was so great that the evaluation tests, carried out mainly by units of the 16th Stormo based in Venice, advised against the Z.1007 being used operationally.
Cant Z.1007bis In the meantime, the design had been completely reworked, incorporating three 1,000 hp Piaggio IX radials. The redesigned Z.1007bis flew in 1938. The effectiveness of the changes were shown in flight-testing and evaluations of the 8 pre-series aircraft. The Z.1007bis proved to have a maximum speed of 283 mph at an altitude of 15,100 ft, a range of 1,242 miles and a maximum ceiling of 27,630 ft, with a 5 man crew. Defensive armament was 2-12.7mm machine guns in ventral and top turrets and 2-7.7mm machine guns in beam positions. The Z.1007bis had a maximum bomb load of 2,646 lbs of bombs or 2 17.7-inch torpedoes.
Deliveries of the Z.1007bis commenced in early 1940 to the 106th and 107th Groups of the 47th Stormo. However, none could be considered operational when Italy entered the war. The Z.1007's first mission occurred in September with attacks on Malta and Tunis.
The 1007bis was the last bomber to retain Piaggio engines until 1942, when Piaggio began building Fiat ‘Stella Dorata’ series engines with power ratings from 1,000 to 1,500hp.
Cant Z.1007ter The final version was the Z.1007ter, which was the most numerous of the type. Stella Dorata series engines of 1,100hp were installed, this rating being selected as it required only minor changes to the aircraft, which (being wooden) could not absorb much additional pwoer. This variant appeared late in 1942. With this engine fit the Z.1007ter had a top speed of 304 mph and a ceiling of 32,890 ft.
Cant Z.1018 Leone
The finest bomber produced in Italy during World War II and a match for any medium bomber produced anywhere else, , the Leone (lion) the last by Filippo Zappata before he left CANT for Breda, and also his first airplane of all-metal construction.
The Z.1018 embodied the lessons of all of Zappata's previous warplanes for CANT. The Z.1018 was a very clean cantilever low-wing monoplane type with two engines. The first prototype was basically an aerodynamic test machine.
The prototype made its maiden flight in 1940 and demonstrated exceptional promise. It was soon followed by five more all-metal prototypes which refined the design. By the end of 1940 it was quite obvious that this machine was the replacement for the RAI medium bomber fleet. The prototypes were used for the evaluation of a number of power plants including:
- two 1,500-hp Piaggio P.XII RC.35 radials,
- two 1,400-hp Piaggio P.XV RC.45 radials,
- two 1,400-hp Alfa Romeo 135 RC.32 Tornado radials
- two imported Kinsei 1,500hp radials
- two 1,475-hp Fiat RA.1050 RC.58 Tifone inverted-Vee engines.
By early 1941 it was obvious that this bomber held second priority for Stella Dorata engines in the 1,500hp class, and Marshall Balbo was throwing his own weight behind the type’s production. It was actually clear from the beginning of the flight test program that the performance of the Leone was so high that a production order was certain. This materialized in January 1941 in the form of an initial contract for 600 aircraft. Despite this, it did not really start to flow from the production lines in quantity until August 1942. This was mostly due to Cant and Caproni (the major subcontractor) having to both retool and reform their production processes.
With the increasing Allied bombing, the Leone was the first Italian aircraft to be produced in dispersed facilities, and this contributed to the production delay.
Such was the potential of the basic design that two important derivatives were proposed. The first of these was a heavy fighter was a fixed forward armament of 7 20mm cannon as well as a defensive outfit based on three 12.7mm trainable machine guns. The second was a night-fighter with German Lichtenstein SN-2 radar with the antenna in the nose. Both these fighter models had an estimated maximum speed of 395 mph, but they remained prototypes, the IMAM Ro.58 proving to adequately fill these roles.
The Leone was a much-respected opponent from the Allied perspective. It was used in the longer range and more dangerous RAI strikes and earned an enviable reputation. A postwar version was also produced.
Fiat BR.20 Cigogna
This bomber was first proposed by Celestino Rosatelli , who envisioned a standardized bomber, in 1934. The BR.20 was first flown on 10 February 1936 at Torino Alitalia and the first 20 units were delivered on 26 November 1937. The Fiat BR.20 Cicogna was the standard Italian bomber of the mid to late 1930's, but it proved to be obsolescent during the French campaign during Italy's entry into World War Two
Although the aircraft looked realtively sleek and modern, it was already outclassed by other competitors. Nevertheless, a total of 234 BR.20's, 279 BR.20M's and 15 BR.20Bis were built. The BR.20M (Modified) and the BR.20Bis were unique to the original in the change of nose section and engines.
BR.20bis. The only new variant to appear during the war was the BR.20bis. These were rebuilt BR.20 with 1,300hp Stella Dorata engines, crew and fuel tank protection, two bunks, a galle and new nose and dorsal turrets with a 12.7mm SAFAT MG in each. Bomb load was reduced to a maximum of 1,000lb, but this was rarely used, additional fuel normally replacing it. This variant had greatly increased fuel supply and a normal range of 2,560 nautical miles. The BR.20bis served in relatively small numbers, and most were based at Bordeaux as convoy scouts for the Italian submarine force based there.
Piaggio P.108
The Piaggio P.108 was the only RAI heavy four-engine bomber of World War Two. Too few were built to play a decisive role in the war, even though over 400 P.108 were built. The first prototype was finished in 10/39 and had a very advanced defensive armament for its day of two 7.7 mm machine waist guns, a 12.7 mm machine gun in the lower turret and a similar weapon in the nose turret, and two remotely-controlled twin gun turrets in outer engine nacelles. The first Allied bomber with a similar armament was the Boeing B 29, developed four years later.
The bomb load of the first production version (P.108B) was 7,700 lbs, all carried internally in the bomb bay. The P.108 B was an all-metal cantilever low-wing monoplane with a retractable under-carriage, originally driven by four 1,350 hp Piaggio P.XII radial engines. Nine were built.
The major problem with the type was these engines. They were hard to build, and temperamental, rarely delivering the rated power. When Fiat started to produce the Stella Dorata series, there were already p.108C airframes waiting for the engines. Marshall Balbo had arranged for Piaggio to obtain ten Mitsubishi 1,530hp Kasei engines for trials with two of these airframes. As part of this deal the Japanese Military Mission assisted with and obtained access to the results of the trials. The trials were very successful, and the Fiat versions of the Kasei (also built under the Stella Dorata series) were scheduled for the type.
Operational experience and the trend of the war saw the type built as the Piaggio P.108C night bomber, with reduced armament, heavier bombload and longer range. The nose turret was deleted, as were the waist guns for night missions. However, the barbette guns actually worked, they and the belly turret were retained. In this form, the P.108 was not much inferior to an Avro Lancaster, and was superior in most respects to the Handley-Page Halifax.
All of this, and the need for a different training regime delayed introduction of the type. The first unit of the RAI to operate the P.108 C was the 274th Long-Range Bombardment Group. This unit was formed in April 1941 as the first machines came off the production line. The training of the crews lasted far longer than anticipated and it took nearly a year for the 274th to become operational (February 1942). The most spectacular raids with the P. 108 B were flown in 1942 when very effective night attacks were conducted against Algiers and Gibraltar. Several versions were planned from the P. 108. These included the P.108A, which had a 102 mm anti-shipping gun in the nose; the P.108D airliner and the P.108T transport. The latter two versions had a larger diameter fuselage for transporting passengers or freight. However, the demand for P.108C was so strong that few were built.
The second P.108C group (275th Long-Range Bombardment Group) were established in June 1941 and became operational in May 1942. They were quickly transferred to the East where they quickly established an excellent reputation, with the Luftwaffe nicknaming them ‘Group Ural’. They were responsible for devastating attacks on the enormous new Soviet industrial facilities built east of Moscow, these huge facilities proving to be very vulnerable to bombing. The P.108C also conducted riverine aerial minelaying in the USSR, causing serious disruption to transport. The Luftwaffe were quick to see advantage in the type which in 1943 became the only RAI type to be operational with Hs.293 and Fritz X. These were fitted to only a few machines which were then used for attacks on the Soviet railway system. The flights fitted with Fritz X became proficient at destroying Soviet railway bridges, and had a disproportionate impact on the war.
The two groups rotated regularly. While few in number, the P.108C force had an impact out of proportion to its size.
Savoia-Marchetti SM.79 Sparviero (Sparrowhawk)
The SM.79 was a rugged tri-motor which formed a mainstay of the RAI during WWII. In 1940, well over 50% of Italy's 1,000 bombers were SM.79s, which also turned out to be one of the best land based torpedo bombers of the war.
The prototype flew on 9 Feb 35 powered by 3 750 hp Alpha Romeo 125 RC.34 engines. It was developed from a civil airliner and had the distinctive hump on the upper forward fuselage that housed the forward and dorsal gunner's position, earning it the nickname of "Gobbo Maledetto" (Damned Hunchback). The last RAI bomber mission of the war was conducted by SM.79 and the type earned a legendary reputation.
The plane was a mix of steel tubes, light alloy, wood and fabric with a high wing load that demanded long airstrips.
Maximum speed was 270 mph with a range of 1,243 miles and a service ceiling of 23,000 ft. The SM.79 was armed with a 12.7mm machine gun firing ahead through the roof of the humpback, a 12.7mm machine gun firing from the dorsal (rear) part of the hump, a 12.7 mm machine gun firing through the ventral position of the gondola and 2 7.7 mm machine guns firing from the side windows. Up to 2,750 lbs of bombs or a 17.7 in torpedo could be carried.
The first SM.79s entered service in late 1936, just in time to fly in the Spanish civil war with the Italian contingent where it established an excellent reputation. In October 1939, the RAI began receiving the SM.79II with 1,000 hp Piaggio engines, which was the main version built. The SM.79III, of which a handful were built, had a 20mm cannon in place of the forward firing 12.7mm machine gun and did away with the ventral gondola.
In 1943, the SM.79IV enters service. By this time the machine’s margin for improvement was nearly at an end. This was known and it was the reason that it was the last Italian bomber to benefit from engine replacement. It received Stella Dorata series engines with a 1,300hp rating. Speed improvement was small but performance when damaged and survivability was improved, as was load carrying capacity.
Scheduled to be replaced by the Cant Z.1018 Leone, the SM.79 had to remain in production as it consumed much less light metal to build. In effect, it was the ‘Italian Wellington’, performing a multiplicity of tasks further back in the threat envelope than the Leone.
A total of approximately 2,200 were built.
Savoia-Marchetti SM.81
In 1935, the SM.81 Pipistrello (Bat) made its debut and marked a definite step forward in the development of military aviation. The excellent overall qualities of this aircraft were first tested in the Ethiopian campaign and then in the Spanish Civil War. The SM.81s success in combat directly transformed into a series of orders that eventually led to the production of 534 SM.81. However, as in the case of other combat planes produced in that same period, the Spanish Civil War did not provide very reliable proof of what subsequent needs were to be. The SM.81, clearly out of date by the outbreak of World War II, remained in service for the duration of hostilities, operating on almost all fronts, although it was gradually phased out to play a secondary role as a transport.
The SM.81's direct predecessor was the trimotor SM.73, a commercial airplane, whose prototype appeared on 6/4/34, and which was an immediate commercial success. The SM.73 provided the basis for SIAI Marchetti's construction formula, a three-engine, low-wing monoplane with a wood and metal structure and wood and fabric covering. The military version was presented toward the end of the year and was subjected to a whole series of operational tests by the RAI before going into mass production.
As in the case of the civilian version, the fitting of several types of engines was also planned for the SM.81, and each of the engines characterized a particular version of the aircraft. These included the 680 hp Piaggio IX, 700 hp Piaggio X, 680 hp Alfa Romeo, 900 hp Alfa Romeo and the 1,000-hp Gnome Rhone 14K engines. Defensive armament consisted of 6 - 7.7mm machineguns, a pair in the retractable ventral position, a pair firing rearward from the back of the cockpit and two in lateral positions in the fuselage. Normal bomb load was 2,000 lbs, but the maximum load was 4,415 lbs of bombs.
The SM.81 went into service early in 1935 and made its military debut in Africa that same year. After the experiences of the Spanish Civil War, the appearance of the stronger and more reliable SM.79 consigned the older SM.81 to a secondary role. At the beginning of World War II, the SM.81 was gradually withdrawn from front-line service in national territory and was used mainly as transport aircraft.
The SM.81 with the 670 hp Piaggio X engines had a maximum speed of 211 mph at 3,281 ft; a service ceiling of 22,966 ft; and a range of 1,243 miles. With the 680 hp Alfa Romeo engines, the maximum speed was 211 mph at 13,210 ft; service ceiling of 23,000 ft and a range of 1,200 miles.
Savoia-Marchetti SM.84
In 1939, the RAI began to think about a replacement for the successful SM.79. The first flight of the prototype took place on 6/5/40. Marchetti based the design on the SM.79 airframe, using the same wings and modifying the fuselage and empennage. The fuselage lacked the SM.79 humpback and had a twin tail. It was powered by three 1,000-hp Piaggio P.XI radial engines driving three-bladed variable-pitch metal propellers. Defensive armament consisted of four 12.7mm machineguns in the back, belly and 2 on the sides of the aircraft. The bomb load could be housed either in the belly (2,207-lb) or under wing (2 torpedoes, rockets or 3,532 lbs of bombs). Top speed was 268 mph at 15,000 ft with a service ceiling of 25,900 ft and a range of 1,137 miles.
When the SM.84 prototype began its evaluation tests it immediately proved to have a series of problems, especially at takeoff and landing, principally caused by the weight of the wings and by the inadequacy of the vertical empennage. The hydraulic system was prone to failure, which would cause the loss of an operational aircraft. The Piaggio engines were also unreliable and difficult to build. With the SM.79 exhibiting better performance and reliability, and the much more advanced Cant Z.1018 also at prototype stage in 1940, the SM.84 was cancelled in October of that year. The sole prototype was used as a company transport until it was lost due to a hydraulic failure which caused the flaps and undercarriage to lower while in flight.
